CN115347791A

CN115347791A - Resonant switching type power conversion circuit

Info

Publication number: CN115347791A
Application number: CN202210359067.9A
Authority: CN
Inventors: 刘国基; 杨大勇; 白忠龙
Original assignee: Richtek Technology Corp
Current assignee: Richtek Technology Corp
Priority date: 2021-05-13
Filing date: 2022-04-07
Publication date: 2022-11-15
Also published as: TW202245393A; TWI801187B

Abstract

A resonant switching power conversion circuit, comprising: the switching converter, the control circuit and the pre-charging circuit; the control circuit is used for controlling a first switch of a plurality of switches in the switching converter in a pre-charging mode so as to control the electric connection relation between a first power supply and a first capacitor of a plurality of capacitors in the switching converter, and controlling other switches so as to control the pre-charging circuit to charge the voltage drop of at least one capacitor to a preset voltage when the voltage drop of the capacitor is lower than the preset voltage; in the starting mode, the first operating signal and the second operating signal are respectively used for operating the plurality of switches so as to switch the electrical connection relation of the corresponding capacitors, so that the switching converter operates in the starting mode after the pre-charging mode is finished; in the start-up mode, the first and second operation signals are respectively switched to the conduction level for a conduction period, and the time lengths of the conduction periods of the plurality of segments are gradually increased.

Description

Resonant switching type power conversion circuit

Technical Field

The present invention relates to a resonant switching power conversion circuit, and more particularly, to a resonant switching power conversion circuit capable of being pre-charged.

Background

Fig. 1 shows a conventional power converter 10. The conventional power converter 10 includes a front-end dc-dc converter 101 for start-up control, which has two switches Qf1 and Qf2, an inductor Lf, a capacitor Cf, and a buck controller 1011. In steady state operation, the front-end dc-dc converter 101 generates additional power consumption and heat energy, so the overall efficiency is reduced.

In view of the above, the present invention provides an innovative resonant switching power conversion circuit to overcome the above-mentioned shortcomings in the prior art.

Disclosure of Invention

In one aspect, the present invention provides a resonant switching power conversion circuit for converting a first power to a second power or vice versa, the resonant switching power conversion circuit comprising: at least one switching converter; a control circuit for controlling the switching converter; and a pre-charge circuit coupled between the control circuit and the at least one switching converter; wherein the switching converter comprises: a plurality of capacitors; a plurality of switches, which are correspondingly coupled with the plurality of capacitors and controlled by the control circuit, and are used for switching the electrical connection relation of the corresponding capacitors; at least one first inductor connected in series with at least one of the capacitors; and at least one second inductor connected in series with at least one of the plurality of capacitors; the control circuit is coupled to the first power supply, the second power supply and the plurality of switches, and is configured to control a first switch of the plurality of switches to control an electrical connection relationship between the first power supply and a first capacitor of the plurality of capacitors when the switching converter operates in a pre-charge mode, and to control the other switches to control the pre-charge circuit to charge a voltage drop of at least one of the plurality of capacitors to a predetermined voltage when the voltage drop of the at least one of the plurality of capacitors is lower than the predetermined voltage; wherein, the first switch is electrically connected between the first power supply and the first capacitor; in a starting mode, a first operation signal and at least one second operation signal are respectively used for correspondingly operating the switches so as to switch the electrical connection relation of the capacitors corresponding to the switches, so that the resonant switching type power conversion circuit is operated in the starting mode after the pre-charging mode is finished; in the start-up mode, the first operating signal and the at least one second operating signal are respectively switched to a conducting level for a conducting period, and the conducting periods of the segments are not overlapped with each other, wherein the time lengths of the conducting periods of the segments are gradually increased; in a resonant voltage conversion mode, the first operation signal and the at least one second operation signal are respectively used for correspondingly operating the switches to switch the electrical connection relation of the capacitors corresponding to the switches, so that the resonant switching power conversion circuit is operated in the resonant voltage conversion mode after the start mode is finished to convert the first power supply into the second power supply or convert the second power supply into the first power supply; in the resonant voltage conversion mode, the first operating signal and the at least one second operating signal are respectively switched to the conducting level for a conducting period, and the conducting periods are not overlapped with each other, so that a first program and at least one second program of the resonant voltage conversion mode are not overlapped with each other; in the first program, the switches are controlled by the first operation signal, so that the capacitors and the at least one first inductor are connected in series between the first power supply and the second power supply to form a first current path; in the at least one second program, the switches are controlled by the at least one second operation signal, so that each capacitor and the corresponding second inductor are connected in series between the second power supply and a ground potential, and a plurality of second current paths are formed at the same time or alternately; the first program and the at least one second program are repeatedly and alternately sequenced to convert the first power source into the second power source or convert the second power source into the first power source.

In one embodiment, in the first procedure, the first operation signal controls the switches to connect at least one of the capacitors in parallel with the second power source, and in the second procedure, the second operation signal controls the switches to connect at least one of the capacitors in parallel with the second power source, wherein the capacitor connected in parallel with the second power source in the first procedure is different from the capacitor connected in parallel with the second power source in the second procedure.

In one embodiment, the plurality of capacitors includes the first capacitor, a second capacitor, and a third capacitor coupled to each other; in the first program, the switches control the first capacitor and the third capacitor to be connected in series between the first power supply and the second power supply, and control the second capacitor and the second power supply to be connected in parallel; in the second procedure, the switches control the second capacitor and the first capacitor to be connected in series between the second power supply and the grounding potential, and control the third capacitor to be connected in parallel with the second power supply.

In one embodiment, the plurality of switches includes: a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a seventh switch, an eighth switch, a ninth switch and a tenth switch; in the first procedure, the first switch, the second switch and the third switch are conducted to control the first capacitor and the third capacitor to be connected in series between the first power supply and the second power supply, the fourth switch and the fifth switch are conducted to control the second capacitor and the second power supply to be connected in parallel, and the sixth switch to the tenth switch are not conducted; in the second procedure, the sixth switch, the seventh switch and the eighth switch are turned on to control the second capacitor and the first capacitor to be connected in series between the second power supply and the ground potential, and the ninth switch and the tenth switch are turned on to control the third capacitor and the second power supply to be connected in parallel.

In one embodiment, the plurality of capacitors further includes an output capacitor coupled to the first capacitor, the second capacitor, and the third capacitor, the predetermined voltage includes a first predetermined voltage and a second predetermined voltage, and the control circuit performs at least one of the following operations in the pre-charge mode: (1) Turning on the fourth switch, the fifth switch, the seventh switch, the ninth switch and the tenth switch, and controlling the pre-charge circuit to charge the voltage drop of the output capacitor, the third capacitor and the second capacitor to the first preset voltage; (2) Turning on the second switch and the tenth switch, and controlling the pre-charge circuit to charge the voltage drop of the third capacitor to the first preset voltage; (3) Turning on the fifth switch, the seventh switch and the eighth switch, and controlling the pre-charge circuit to charge the voltage drop of the second capacitor and the first capacitor to the first preset voltage; or (4) turning on the eighth switch and controlling the pre-charge circuit to charge the voltage drop of the first capacitor to the second preset voltage.

In one embodiment, the first predetermined voltage is a target voltage of a second voltage of the second power supply, and the second predetermined voltage is twice the target voltage of the second power supply.

In one embodiment, the resonant switching power conversion circuit further includes one of: (1) The third capacitor is also directly connected in series with the first inductor to form a first resonant tank, and the second capacitor is also directly connected in series with the second inductor to form a second resonant tank; wherein in the first program, the switches further control the first resonant tank and the first capacitor to be connected in series between the first power supply and the second power supply, and further control the second resonant tank and the second power supply to be connected in parallel; wherein in the second procedure, the switches also control the second resonance tank and the first capacitor to be connected in series between the second power supply and the ground potential, and also control the first resonance tank and the second power supply to be connected in parallel; (2) The first inductor and the second inductor are a single same inductor, and the inductor is coupled between the second power supply and a switching node; in the first program, the switches further control the first capacitor and the third capacitor to be connected in series between the first power supply and the second power supply after being connected in series with the inductor through the switching node, and control the second capacitor to be connected in parallel with the second power supply after being connected in series with the inductor through the switching node; in the second procedure, the switches also control the second capacitor and the first capacitor to be connected in series between the second power supply and the ground potential after being connected in series with the inductor through the switching node, and also control the third capacitor to be connected in parallel with the second power supply after being connected in series with the inductor through the switching node; or (3) wherein the first inductor is coupled between the second power source and a first switching node, and the second inductor is coupled between the second power source and a second switching node; in the first procedure, the switches also control the first capacitor and the third capacitor, and are connected in series between the first power supply and the second power supply after being connected in series with the first inductor through the first switching node, and also control the second capacitor to be connected in parallel with the second power supply after being connected in series with the second inductor through the second switching node; in the second procedure, the switches also control the second capacitor and the first capacitor to be connected in series between the second power supply and the ground potential after being connected in series with the second inductor through the second switching node, and also control the third capacitor to be connected in parallel with the second power supply after being connected in series with the first inductor through the first switching node.

In one embodiment, the at least one switching converter includes a first switching converter and a second switching converter, wherein the first switching converter and the second switching converter are coupled in parallel between the first power source and the second power source, and the first switching converter and the second switching converter switch the corresponding switches of each switching converter in opposite phases.

In one embodiment, the resonant switching power conversion circuit has the feature (3), and the first inductor and the second inductor are both operated in a continuous conduction mode.

In one embodiment, the resonant switching power conversion circuit further includes an upper capacitor and a plurality of upper switches, wherein the at least one switching converter includes a first switching converter and a second switching converter; wherein the upper capacitor, the plurality of upper switches, the first switching converter and the second switching converter are coupled to each other in a basic topology; in the first procedure, the upper layer switches control the first switching converter and the upper layer capacitor to be connected in series between the first power supply and the second power supply and control the second switching converter to be connected in parallel with the second power supply; in the second procedure, the upper switches control the second switching converter and the upper capacitor to be connected in series between the second power supply and the ground potential, and control the first switching converter and the second power supply to be connected in parallel.

In one embodiment, the ratio of the first voltage of the first power source to the second voltage of the second power source is 8.

In one embodiment, the resonant switching power converter circuit further comprises a further upper capacitor, a plurality of further upper switches, a further upper first switching converter and a further upper second switching converter, wherein the further upper capacitor, the plurality of further upper switches, the further upper first switching converter and the further upper second switching converter are further coupled to each other in a recursive expansion corresponding to the basic topology; wherein the first switching converter of the upper layer and the second switching converter of the upper layer correspond to the resonant switching power conversion circuit of the next layer recursively.

In an embodiment, the at least one first inductor is a plurality of charging inductors respectively connected in series with the plurality of capacitors in a corresponding manner, wherein the at least one second inductor is a plurality of discharging inductors, and in the first procedure, the plurality of capacitors and the plurality of charging inductors are connected in series between the first power source and the second power source by switching the plurality of switches to form the first current path; in the second procedure, the plurality of charging inductors are used as the plurality of discharging inductors, and the plurality of discharging inductors and the plurality of capacitors are respectively connected in series between the second power supply and the ground potential correspondingly through the switching of the plurality of switches to form the plurality of second current paths, wherein the plurality of second current paths are connected in parallel with each other.

In an embodiment, the at least one first inductor and the at least one second inductor have mutual inductance (coupled inductance) therebetween.

In an embodiment, the at least one first inductor and the at least one second inductor having mutual inductance with each other are configured as mutual inductors (coupled inductors) or as a transformer.

In one embodiment, the at least one first inductor is a single first inductor, and the at least one second inductor is a single second inductor.

In one embodiment, the inductance of the single first inductor is equal to the inductance of the single second inductor.

In an embodiment, the at least one first inductor and the at least one second inductor are a single same inductor.

In one embodiment, the first process has a first resonant frequency, and the second process has a second resonant frequency, and the first resonant frequency is the same as the second resonant frequency.

In one embodiment, the first program has a first resonant frequency, the second program has a second resonant frequency, and the first resonant frequency is different from the second resonant frequency.

In one embodiment, a voltage conversion ratio of the first voltage of the first power source to the second voltage of the second power source of the switching converter is 4:1, 3:1 or 2:1.

In one embodiment, a voltage conversion ratio of the first voltage of the first power source to the second voltage of the second power source of the switching converter is 4:1.

In an embodiment, in a steady state, a ratio of the voltage across the first capacitor to the second voltage is 2, a ratio of the voltage across the third capacitor to the second voltage is 1, and a ratio of the voltage across the second capacitor to the second voltage is 1.

In an embodiment, the first inductor and the second inductor are a single same inductor, and in a 2-fold conversion mode, a part of the switches are constantly turned on, another part of the switches are constantly turned off, another part of the switches are used for switching a capacitor of the second capacitor or the first capacitor, so that the capacitor and the inductor are connected in series between the first power supply and the second power supply in the first procedure, and after the capacitor and the inductor are connected in series in the second procedure, the capacitor and the second power supply are connected in parallel, so that a ratio of a first voltage of the first power supply to a second voltage of the second power supply is 2, wherein the inductor and the capacitor operate in a resonant mode to realize power conversion between the first power supply and the second power supply.

In an embodiment, in a 2-time conversion mode, a part of the switches are constantly turned on, another part of the switches are constantly turned off, and another part of the switches are used to switch the first capacitor, so that the first capacitor and the first inductor are connected in series between the first power supply and the second power supply in the first procedure, and are connected in parallel to the second power supply after the first capacitor and the second inductor are connected in series in the second procedure, so that a ratio of a first voltage of the first power supply to a second voltage of the second power supply is 2, wherein the first inductor, the second inductor, and the first capacitor operate in a resonant mode to realize power conversion between the first power supply and the second power supply.

In an embodiment, the first inductor and the second inductor are a single same inductor, and in a 3-fold conversion mode, a part of the switches are constantly turned on, another part of the switches are constantly turned off, and another part of the switches are used to switch the first capacitor and the third capacitor, so that the first capacitor, the third capacitor and the inductor are connected in series between the first power supply and the second power supply in the first procedure, and the first capacitor and the third capacitor are connected in parallel and then connected in series with the inductor and then connected in parallel with the second power supply in the second procedure, so that a ratio of a first voltage of the first power supply to a second voltage of the second power supply is 3, wherein the inductor and the first capacitor, and/or the inductor and the third capacitor operate in a resonant manner to realize power conversion between the first power supply and the second power supply.

In one embodiment, in a 3-fold conversion mode, a part of the switches are constantly turned on, another part of the switches are constantly turned off, and another part of the switches are used to switch the first capacitor and the third capacitor, so as to connect the first capacitor, the third capacitor and the first inductor in series between the first power source and the second power source in the first procedure, and connect the first capacitor and the third capacitor in series with the second inductor and the first inductor respectively in the second procedure, and then connect the first capacitor and the third capacitor in parallel with the second power source, so that a ratio of a first voltage of the first power source to a second voltage of the second power source is 3, wherein the second inductor and the first capacitor, and/or the first inductor and the third capacitor operate in a resonant manner to realize power conversion between the first power source and the second power source.

In one embodiment, the predetermined voltage has a fixed proportional relationship with the first voltage of the first power source.

In one embodiment, the first inductor and the second inductor are a single same inductor, and the capacitance of the first capacitor is much larger than the capacitance of the third capacitor and the second capacitor, so that the first resonant frequency of the third capacitor and the inductor and the second resonant frequency of the second capacitor and the inductor are both higher than or equal to 10 times of the third resonant frequency of the first capacitor and the inductor.

In another aspect, the present invention provides a resonant switching power conversion circuit for converting a first power to a second power or vice versa, the resonant switching power conversion circuit comprising: at least one resonant tank having a resonant capacitor and a resonant inductor connected in series with each other; a plurality of switches, coupled to the at least one resonant tank, for switching an electrical connection relationship of the corresponding resonant tank according to a corresponding first operation signal and a corresponding second operation signal in a resonant voltage conversion mode to correspond to a first resonant procedure and a second resonant procedure, wherein in the first resonant procedure, the corresponding resonant tank is resonantly charged, and wherein in the second resonant procedure, the corresponding resonant tank is resonantly discharged; a control circuit for controlling the plurality of switches; a pre-charge circuit coupled between the control circuit and the switches except for a first switch; and at least one non-resonant capacitor coupled to the at least one resonant tank, wherein in the resonant voltage conversion mode, the first operating signal and the second operating signal switch the electrical connection between the non-resonant capacitor and the at least one resonant tank, and the voltage across the non-resonant capacitor is maintained in a fixed ratio to the first power supply; the control circuit is coupled to the first power supply, the second power supply and the switches, and is configured to control the first switch of the switches to control an electrical connection relationship between the first power supply and the at least one resonant tank and control the other switches to control the pre-charge circuit to charge at least one of the resonant capacitor and the at least one non-resonant capacitor to a predetermined voltage when a voltage drop of the at least one of the resonant capacitor and the at least one non-resonant capacitor is lower than the predetermined voltage when the resonant switching power conversion circuit operates in a pre-charge mode; wherein, the first switch is electrically connected between the first power supply and the resonant capacitor; in a starting mode, the first operation signal and the second operation signal are respectively used for correspondingly operating the switches to switch the electrical connection relation between the non-resonant capacitor and the at least one resonant tank, so that the resonant switching power conversion circuit is operated in the starting mode after the pre-charging mode is finished; in the start mode, the first operation signal and the second operation signal are respectively switched to a conducting level for a conducting period, and the conducting periods of the segments are not overlapped with each other, wherein the time lengths of the conducting periods of the segments are gradually increased; in the resonant voltage conversion mode, the first operating signal and the second operating signal are respectively switched to the on level for a section of on period, and the plurality of sections of on periods are not overlapped with each other, so that the first resonant procedure and the second resonant procedure are not overlapped with each other, and the resonant switching power conversion circuit is operated in the resonant voltage conversion mode after the start-up mode is finished, and the first resonant procedure and the second resonant procedure are repeatedly and alternately sequenced to convert the first power into the second power or convert the second power into the first power.

In an embodiment, the predetermined voltage is a target voltage of the second power source.

In an embodiment, the predetermined voltage is a positive integer multiple of a target voltage of the second power source.

In one embodiment, the pre-charge circuit includes: a current source for generating a pre-charge current; and a pre-charge switch circuit coupled between the current source and the plurality of switches except the first switch, wherein in the pre-charge mode, the control circuit controls the pre-charge switch circuit and the plurality of switches except the first switch to control an electrical connection relationship between the current source and the at least one of the resonant capacitor and the at least one non-resonant capacitor, and further charges a voltage drop of the at least one of the resonant capacitor and the at least one non-resonant capacitor to the predetermined voltage according to the pre-charge current.

In one embodiment, the control circuit includes: a duty ratio decision circuit for comparing a ramp-up voltage of a ramp-up node with a periodic waveform signal to generate a duty ratio signal; a duty ratio distribution circuit for generating the first operation signal and the second operation signal according to the duty ratio signal; and a ramp-up voltage generating circuit coupled to the duty cycle determining circuit for generating the ramp-up voltage of the ramp-up node in the start-up mode; the gradually-rising voltage of the gradually-rising node gradually rises in the starting mode, so that the duty ratio of the first operation signal and the duty ratio of the at least one second operation signal correspondingly gradually rise.

In one embodiment, in the pre-charge mode, the control circuit controls a conduction level of the first switch, so that a pre-charge current flows from the first power source to the at least one of the resonant capacitor and the at least one non-resonant capacitor through the first switch, so as to charge a voltage drop of the at least one of the resonant capacitor and the at least one non-resonant capacitor to the predetermined voltage.

In an embodiment, at least one of the resonant capacitors includes a first resonant capacitor and a second resonant capacitor, the predetermined voltage includes a first predetermined voltage, a second predetermined voltage and a third predetermined voltage, the switches include a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a seventh switch, an eighth switch, a ninth switch and a tenth switch, and the control circuit performs at least one of the following operations in the pre-charge mode: (1) Turning on the sixth switch and controlling the pre-charge circuit to charge the voltage drop of the first resonant capacitor to the first preset voltage; (2) Conducting the second switch and the eighth switch, and controlling the pre-charge circuit to charge the voltage drop of the non-resonant capacitor to the second preset voltage; or (3) turning on the second switch, the third switch and the tenth switch, and controlling the pre-charge circuit to charge the voltage drop of the second resonant capacitor to the third preset voltage.

In one embodiment, the first predetermined voltage is three times a target voltage of a second voltage of the second power source, the second predetermined voltage is two times the target voltage of the second voltage, and the third predetermined voltage is the target voltage of the second voltage.

The invention has the advantages that the invention can use the prior switch to achieve the pre-charge operation mode and the hot plug function, can use the prior power level element to realize the start operation, does not need an additional front end DC-DC converter to carry out the start control, can use less elements and save space, can improve the power conversion efficiency without the power loss of the front end DC-DC converter, can reduce the surge current, can support the soft-start and can support the parallel operation for the multiphase resonant switching type capacitance converter (RSCC).

The purpose, technical content, features and effects of the present invention will be more readily understood by the following detailed description of specific embodiments.

Drawings

Fig. 1 is a schematic diagram of a conventional power converter.

Fig. 2 is a circuit diagram of a resonant switching power conversion circuit according to an embodiment of the invention.

Fig. 3 is a circuit diagram illustrating a controller in a resonant switching power conversion circuit according to an embodiment of the invention.

Fig. 4 is a schematic diagram illustrating a control circuit in a resonant switching power conversion circuit according to an embodiment of the invention.

Fig. 5A is a signal waveform diagram illustrating related signals in a start-up mode of a control circuit of a resonant switching power converter circuit according to an embodiment of the invention.

Fig. 5B is a signal waveform diagram illustrating related signals in a start-up mode of a resonant switching power converter circuit according to an embodiment of the invention.

FIG. 6 is a circuit diagram of a resonant switching power conversion circuit according to another embodiment of the present invention.

FIG. 7 is a circuit diagram of a resonant switching power conversion circuit according to another embodiment of the present invention.

FIG. 8 is a circuit diagram of a resonant switching power conversion circuit according to another embodiment of the present invention.

FIG. 9 is a circuit diagram of a resonant switching power conversion circuit according to another embodiment of the present invention.

FIG. 10 is a circuit diagram of a resonant switching power conversion circuit according to another embodiment of the present invention.

Fig. 11 is a circuit diagram of a resonant switching power conversion circuit according to another embodiment of the invention.

FIG. 12 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention.

FIG. 13 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention.

FIG. 14 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention.

FIG. 15 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention.

FIG. 16 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention.

Fig. 17 is a circuit diagram of a resonant switching power conversion circuit according to still another embodiment of the invention.

FIG. 18A is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention.

Fig. 18B is a block diagram of a resonant switching power conversion circuit according to an embodiment of the invention.

FIG. 19 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention.

FIG. 20 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention.

FIG. 21 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention.

FIG. 22 is a circuit diagram of a resonant switching power conversion circuit according to another embodiment of the present invention.

FIG. 23 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention.

FIG. 24 is a circuit diagram of a resonant switching power conversion circuit according to another embodiment of the present invention.

FIG. 25 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention.

Description of the symbols in the figures

10: known power converter

100b: pipeline type resonance switching power supply conversion circuit

101: front-end DC-to-DC converter

1011: voltage reduction controller

20 20a,20b,30, 30a,40, 40a,40b,50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170: resonant switching type power conversion circuit

201 201a,201b,301, 301a,401, 401a,401b,501, 601, 701, 801, 901, 1001, 1101, 1201, 1301, 1401, 1501, 1601, 1701: controller

2011: control circuit

20111: duty ratio decision circuit

20112: duty ratio distribution circuit

20113: gradual-rise voltage generation circuit

2012: pre-charging circuit

202 202a,202b,302, 302a,402, 402a,402b,502, 1502, 1602, 1702: switching converter

1402 1403, 3021, 3021a,3022, 3022a,6021, 6022, 6031, 6032, 10021, 10022, 10031, 10032: resonance tank

5021: transformer device

602 702, 802, 902, 1002, 1002b,1102, 1202, 1302: first switching converter

603 703, 803, 903, 1003, 1003b,1103, 1203, 1303: second switching converter

C1 to C3, C11 to C13, C21, ca, cf, CV1, CV2: capacitor with a capacitor element

CLK: clock signal

CS1, CS2: current source

GA: a first operation signal

GB: second operation signal

Gpr0, gpr1', gpr2, gpr3: precharge operation signal

I1: a first current

I2: the second current

IL1: current of inductor L1

IL2: inductor L2 current

Ipr: pre-charge current

L, L1, L11, L12, L2, L3, lf: (resonant) inductor

Lgc-H: signal

LX: switching node

LX1, LX11: first switching node

LX2, LX12: second switching node

Q1 to Q21, Q28, qf1, qf2: switch with a switch body

S1: pre-charging switch circuit

S2: reset switch

Srst: reset signal

V1: first voltage

V2: second voltage

Va: step-up voltage of step-up node

VC1: capacitor C1 voltage

VC2: capacitor C2 voltage

VC3: capacitor C3 voltage

Vd: duty ratio signal

Vm: intermediate signal

Vpr: second preset voltage

Vramp: periodic waveform signal

Vtgt: target voltage

Detailed Description

The drawings in the present disclosure are schematic and are intended to show the coupling relationship between circuits and the relationship between signal waveforms, and the circuits, signal waveforms and frequencies are not drawn to scale.

Fig. 2 is a schematic diagram of an embodiment of a resonant switching power conversion circuit according to the invention. The resonant switching power conversion circuit 20 is used to convert a first power (corresponding to a first voltage V1 and a first current I1) into a second power (corresponding to a second voltage V2 and a second current I2), or convert the second power into the first power. In this embodiment, the resonant switching power conversion circuit 20 includes a switching converter 202, and the switching converter 202 includes a first capacitor (a capacitor C1), a second capacitor (a capacitor C2), a third capacitor (a capacitor C3), and a plurality of switches Q1 to Q10 coupled to each other.

In one embodiment, in the first procedure, the switches Q1 to Q10 control the first capacitor (capacitor C1) and the third capacitor (capacitor C3) to be connected in series between the first power source and the second power source, and control the second capacitor (capacitor C2) to be connected in parallel with the second power source, and the other end of the second capacitor (capacitor C2) is controlled to be coupled to the ground potential. Specifically, the switches Q1, Q2 and Q3 are turned on to control the first capacitor (capacitor C1) and the third capacitor (capacitor C3) to be connected in series between the first power supply and the second power supply, the switches Q4 and Q5 are turned on to control the second capacitor (capacitor C2) to be connected in parallel with the second power supply, and the switches Q6 to Q10 are turned off. In the first procedure, the control signal GA is enabled to turn on the switch controlled by the control signal GA, and the control signal GB is disabled to turn off the switch controlled by the control signal GB.

In the second procedure, the switches Q1 to Q10 control the second capacitor (capacitor C2) and the first capacitor (capacitor C1) to be connected in series between the second power supply and the ground potential, and control the third capacitor (capacitor C3) to be connected in parallel with the second power supply. In the second procedure, the second capacitor (capacitor C2) and the first capacitor (capacitor C1) are connected in series in reverse between the second power source and the ground potential. Specifically, the switches Q6, Q7 and Q8 are turned on to control the second capacitor (capacitor C2) and the first capacitor (capacitor C1) to be connected in series between the second power supply and the ground potential, the switches Q9 and Q10 are turned on to control the third capacitor (capacitor C3) to be connected in parallel with the second power supply, and the switches Q1 to Q5 are turned off. In the second procedure, the control signal GA is disabled to turn off the switch controlled by the control signal GA, and the control signal GB is enabled to turn on the switch controlled by the control signal GB.

The resonant switching power conversion circuit 20 performs power conversion between the first power and the second power by the above-described periodic operation. In this embodiment, the ratio of the first voltage V1 to the second voltage V2 is 4.

In the second procedure, the second capacitor (the capacitor C2) and the first capacitor (the capacitor C1) are connected in series in an "inverse" manner, which means that the voltage across the second capacitor (the capacitor C2) is opposite to the voltage across the first capacitor (the capacitor C1) (i.e., the positive and negative terminals are opposite in direction).

In the embodiment of converting the first power source into the second power source, in the first process, the first power source charges the first capacitor (capacitor C1) and the third capacitor (capacitor C3) connected in series, and the second capacitor (capacitor C2) is discharged to supply the second power source, i.e., the second capacitor (capacitor C2) charges the capacitor CV2 coupled to the second power source. In the second procedure, the first capacitor (capacitor C1) charges the second capacitor (capacitor C2) and the second power source.

In addition, in the embodiment of converting the second power source into the first power source, in the first procedure, the second power source charges the first capacitor (capacitor C1) and the third capacitor (capacitor C3) which are connected in series, and the second power source charges the second capacitor (capacitor C2). In the second procedure, the second power source charges the third capacitor (capacitor C3), and the second power source charges the first capacitor (capacitor C1) through the second capacitor (capacitor C2).

Through the above-mentioned periodic operation, in the present embodiment, in a steady state (i.e., when the switching converter 202 operates in the resonant voltage conversion mode, as described in detail later), a ratio of the voltage VC1 of the first capacitor (the capacitor C1) to the second voltage V2 is 2, a ratio of the voltage VC3 of the third capacitor (the capacitor C3) to the second voltage V2 is 1, and a ratio of the voltage VC2 of the second capacitor (the capacitor C2) to the second voltage V2 is 1. In the embodiment where the second voltage V2 is 12V, the voltage VC3 across the third capacitor (capacitor C3) and the voltage VC2 across the second capacitor (capacitor C2) are both 12V in the steady state, and it should be noted that since the present invention can maintain the voltage across the capacitor at a lower voltage in the steady state, the capacitor can maintain a higher effective capacitance, and thus the withstand voltage and the volume required by the capacitor can be effectively reduced, and meanwhile, the resonant frequency is more stable and has better transient response. It is also noted that the output current (e.g., corresponding to the second current I2) of the present invention is provided by two channels, thereby reducing ripple.

The capacitors CV1 and CV2 are coupled to the first power source and the second power source, respectively, and correspond to the input capacitor and the output capacitor, respectively, in the embodiment where the first power source is converted into the second power source, or correspond to the output capacitor and the input capacitor, respectively, in the embodiment where the second power source is converted into the first power source.

The switching converter 202 further includes an inductor L1 and an inductor L2, wherein the inductor L1 is coupled between the second power source and the first switching node LX1, and the inductor L2 is coupled between the second power source and the second switching node LX 2. In the first procedure, the switches Q1 to Q10 control the first capacitor (capacitor C1) and the third capacitor (capacitor C3) to be connected in series between the first power source and the second power source after being connected in series with the inductor L1 via the first switching node LX1, and control the second capacitor (capacitor C2) to be connected in parallel with the second power source after being connected in series with the inductor L2 via the second switching node LX 2. On the other hand, in the second routine, the switches Q1 to Q10 control the second capacitor (capacitor C2) and the first capacitor (capacitor C1), and are connected in series between the second power supply and the ground potential via the second switching node LX2 and the inductor L2, and control the third capacitor (capacitor C3) to be connected in series with the inductor L1 via the first switching node LX1, and then connected in parallel with the second power supply. In one embodiment, the inductor L1 and the inductor L2 are both operated in a continuous conduction mode, so that the inrush current and the ripple current can be further reduced.

In one embodiment, the capacitance of the first capacitor C1 is much larger than the capacitance of the third capacitor (capacitor C3) and the capacitance of the second capacitor (capacitor C2), so that the first resonant frequency of the third capacitor (capacitor C3) and the inductor and the second resonant frequency of the second capacitor (capacitor C2) and the inductor are much higher than the third resonant frequency of the first capacitor (capacitor C1) and the inductor, and in a preferred embodiment, the first resonant frequency and the second resonant frequency are both greater than or equal to 10 times the third resonant frequency.

Fig. 3 is a circuit diagram illustrating a controller in a resonant switching power conversion circuit according to an embodiment of the invention. Referring to fig. 2 and fig. 3, the resonant switching power conversion circuit 20 further includes a controller 201. The controller 201 includes a control circuit 2011 and a precharge circuit 2012. The control circuit 2011 is coupled to the first power source, the second power source, the switches Q1 to Q10 and a node between the first switch (e.g., the switch Q1) and the seventh switch (e.g., the switch Q7) for controlling the switching converter 202, and the pre-charge circuit 2012 is coupled between the control circuit 2011 and the switching converter 202. The control circuit 2011 is configured to generate the precharge operation signal Gpr1 to control a first switch (e.g., the switch Q1) of the plurality of switches Q1 to Q10, further control an electrical connection relationship between the first power source and a first capacitor (e.g., the capacitor C1) of the plurality of capacitors (the capacitors C1 to C3) (e.g., the switch Q1 is not turned on to disconnect the first power source from the capacitor C1), and generate the precharge operation signals Gpr2 and Gpr3 to control the other switches (e.g., the switches Q2 to Q10), so as to control the precharge circuit 2012 to charge the voltage drop of at least one of the plurality of capacitors (the capacitors C1 to C3) to a predetermined voltage when the voltage drop of the at least one of the plurality of capacitors (the capacitors C1 to C3) is lower than the predetermined voltage when the switching converter 202 operates in the precharge mode. The control circuit 2011 also generates the precharge operation signal Gpr0 to control the precharge switch circuit S1 in the precharge mode, so that the capacitor CV2, the capacitor C1, the capacitor C2, and/or the capacitor C3 are charged when the precharge operation signals Gpr2 and Gpr3 control the other switches (for example, the switches Q2 to Q10) in the precharge mode, and the precharge current Ipr generated by the current source CS 1.

In one embodiment, during the precharge mode, the control circuit 2011 generates the precharge operation signals Gpr0, gpr1, gpr2, and Gpr3 to perform at least one of the following operations: (1) Turning on the switch Q4, the switch Q5, the switch Q7, the switch Q9, and the switch Q10, and controlling the pre-charge circuit 2012 to charge the voltage drops of the capacitor CV2, the capacitor C3, and the capacitor C2 to a first preset voltage; (2) Turning on the switch Q2 and the switch Q10, and controlling the pre-charge circuit 2012 to charge the voltage drop of the capacitor C3 to the first predetermined voltage; (3) Turning on the switch Q5, the switch Q7 and the switch Q8, and controlling the pre-charge circuit 2012 to charge the voltage drops of the capacitor C2 and the capacitor C1 to a first preset voltage; or (4) turn on the switch Q8, and control the pre-charge circuit 2012 to charge the voltage drop of the capacitor C1 to the second preset voltage. In one embodiment, the first predetermined voltage is a target voltage of the second voltage V2, and the second predetermined voltage is twice the target voltage of the second voltage V2.

In another embodiment, in the pre-charge mode, the control circuit 2011 controls a conducting degree of the first switch (e.g., the switch Q1) to enable a pre-charge current to flow from the first power source to at least one of the capacitors (e.g., the capacitors C1 to C3) through the first switch, so as to charge the voltage drop of the at least one of the capacitors (e.g., the capacitors C1 to C3) to a predetermined voltage. In one embodiment, the predetermined voltage is a target voltage of the second voltage V2 of the second power source. In another embodiment, the predetermined voltage is a positive integer multiple, such as but not limited to one or two times, of the target voltage of the second voltage V2 of the second power source. In this embodiment, the first switch is a switch Q1, and the first capacitor is a capacitor C1. As shown in fig. 2 and 3, the first switch (the switch Q1) is electrically connected between the first power source and the first capacitor (the capacitor C1).

In the start-up mode, the first operation signal GA and the at least one second operation signal GB are respectively used to correspondingly operate the switches Q1 to Q10 to switch the electrical connection relationship of the capacitors corresponding to the switches Q1 to Q10, so that the resonant switching power conversion circuit 20 operates in the start-up mode after the pre-charge mode is finished. In the active mode, the first operation signal GA and the at least one second operation signal GB are respectively switched to the on-level for a conducting period, and the conducting periods of the segments do not overlap each other. In one embodiment, the time duration of the segment conducting periods gradually increases.

And entering a resonant voltage conversion mode after the starting mode is finished. In the resonant voltage conversion mode, the first operation signal GA and the at least one second operation signal GB are respectively used to correspondingly operate the switches Q1 to Q10 to switch the electrical connection relationship of the capacitors corresponding to the switches Q1 to Q10, so that the resonant switching power conversion circuit 20 operates in the resonant voltage conversion mode after the start-up mode is finished to convert the first power into the second power or convert the second power into the first power. In one embodiment, the resonant switching power converter circuit 20 of the present invention can be hot-plugged (hot swap) from the whole circuit after the first power.

As shown in fig. 3, in an embodiment, the pre-charge circuit 2012 includes a current source CS1 and a pre-charge switch circuit S1. The current source CS1 is configured to generate a precharge current Ipr, and the precharge switch circuit S1 is coupled between the current source CS1 and a plurality of switches (e.g., the switches Q2 to Q10) other than the first switch. In the pre-charge mode, the control circuit 2011 generates a pre-charge operation signal Gpr0 to control the pre-charge switch circuit S1; and generates the precharge operation signals Gpr2 and Gpr3 to control the switches (the switches Q2 to Q10) except the first switch (the switch Q1), and to control the electrical connection relationship between the current source CS1 and the at least one of the capacitors (the capacitors C1 to C3), so as to charge the voltage drop of the at least one of the capacitors (the capacitors C1 to C3) to the preset voltage according to the precharge current Ipr.

In the precharge mode, the control circuit 2011 may generate the precharge operation signal Gpr1 to control the on-state of the switch Q1, so that the first current I1 is used as the precharge current; the control circuit 2011 further generates the precharge operation signals Gpr2 and Gpr3 to control the other switches (e.g., the switches Q2 to Q10) such that the first current I1 flows from the first power source to at least one of the capacitors (e.g., the capacitors C1 to C3) through the switch Q1 to charge the voltage drop of the at least one of the capacitors (e.g., the capacitors C1 to C3) to the predetermined voltage, and controls the conduction degree of the switch Q1 to charge the voltage drop of the at least one of the capacitors (e.g., the capacitors C1 to C3) to the predetermined voltage when the voltage drop of the at least one of the capacitors (e.g., the capacitors C1 to C3) is lower than the predetermined voltage; alternatively, the control circuit 2011 may generate the precharge operation signal Gpr0 to turn on the precharge switch circuit S1 to generate the precharge current Ipr, and the control circuit 2011 may generate the precharge operation signals Gpr2 and Gpr3 to control the other switches (e.g., the switches Q2 to Q10) so as to control the precharge circuit 2012 to charge at least one of the capacitors (the capacitors C1 to C3) to the predetermined voltage when the voltage drop of the at least one of the capacitors (the capacitors C1 to C3) is lower than the predetermined voltage. Of course, the two pre-charging modes can be operated alternatively or simultaneously.

Fig. 4 is a schematic diagram illustrating a control circuit in a resonant switching power conversion circuit according to an embodiment of the invention. The present embodiment shows a more specific exemplary embodiment of the control circuit 2011, but the control circuit 2011 of the present invention may be implemented with other architectures. As shown in fig. 4, in an embodiment, the control circuit 2011 includes a duty cycle determining circuit 20111, a duty cycle allocating circuit 20112, and a ramp-up voltage generating circuit 20113. The duty ratio determining circuit 20111 is used for comparing a ramp-up voltage Va generated by the ramp-up voltage generating circuit 20113 at a ramp-up node between the current source CS2 and the capacitor Ca with a periodic waveform signal Vramp to generate a duty ratio signal Vd. Wherein the periodic waveform signal Vramp is, for example but not limited to, a triangular wave as shown in fig. 5A. The duty cycle allocating circuit 20112 is configured to generate the first operation signal GA and the at least one second operation signal GB according to the duty cycle signal Vd. In one embodiment, as shown in fig. 4, the duty ratio determining circuit 20111 includes a comparator and a logic and gate, and the duty ratio distributing circuit 20112 includes a flip-flop and a logic and gate. The ramp-up voltage generating circuit 20113 includes a current source CS2, a capacitor Ca, and a reset switch S2.

In the start mode, the current source CS2 of the ramp voltage generating circuit 20113 charges the capacitor Ca to gradually increase the ramp voltage Va at the ramp node, and when the duty ratio determining circuit 20111 compares the ramp voltage Va with the periodic waveform signal Vramp, the duty ratio of the duty ratio signal Vd is gradually increased, so that the duty ratio of the first operation signal GA and the at least one second operation signal GB is also gradually increased, and when the first power source is converted into the second power source or the second power source is converted into the first power source, the inrush current is reduced, and the flexible start is supported.

In an embodiment, when the ramp-up voltage Va rises above the maximum value of the periodic waveform signal Vramp, the duty ratio distribution circuit 20112 may directly enter the resonant voltage conversion mode according to the first operation signal GA and the at least one second operation signal GB generated by the duty ratio signal Vd. Of course, after entering the resonant voltage conversion mode, the duty ratio distribution circuit 20112 may also be turned off, and the other circuits generate the first operation signal GA and the at least one second operation signal GB. In addition, the ramp-up voltage generating circuit 20113 may turn on the reset switch S2 at an appropriate time (e.g., before the start of the next start-up mode) according to the reset signal Srst to discharge the capacitor Ca, so as to reset the ramp-up voltage Va.

Fig. 5A is a signal waveform diagram illustrating signals related to a start-up mode of a control circuit of a resonant switching power conversion circuit according to an embodiment of the invention. A ramp-up voltage Va at the ramp-up node, a periodic waveform signal Vramp, a clock signal CLK, a duty ratio signal Vd, a first operation signal GA, and a second operation signal GB are shown in fig. 5A. As shown in fig. 5A, the ramp-up voltage Va of the ramp-up node gradually rises in the start-up mode. As shown in fig. 5A, in the start-up mode, the time length of the plurality of segment on periods t1 to t4 gradually increases. Therefore, in one embodiment, the duty cycle is gradually increased from 0 to 50%.

Fig. 5B is a signal waveform diagram illustrating signals involved in a start-up mode of a resonant switching power converter circuit according to an embodiment of the invention. The second voltage V2, the second current I2, the capacitor C1 cross-voltage VC1, the capacitor C2 cross-voltage VC2, the capacitor C3 cross-voltage VC3, and the inductor L1 current IL1 are shown in fig. 5B. Fig. 5B shows the resonant switching power conversion circuit after the pre-charge mode, and it can be seen from fig. 5B that the surge current can be further reduced by gradually increasing the time length of the on period in the start-up mode and the resonant voltage conversion mode of the resonant switching power conversion circuit after the pre-charge mode.

As shown in fig. 5B, in the precharge mode, the control circuit 2011 generates the precharge operation signals Gpr2 and Gpr3 to perform, for example, but not limited to, the following operations (4): the switch Q8 is turned on, and the precharge switch circuit S1 in the precharge circuit 2012 is controlled by the precharge operation signal Gpr0, so as to charge the voltage drop of the capacitor C1 to the second predetermined voltage. The second preset voltage Vpr is, for example, twice the target voltage Vtgt of the second voltage V2. Then, in the start mode, the second voltage V2 is gradually increased to the target voltage Vtgt. The voltage ranges of the switching of the capacitor C1 across voltage VC1, the capacitor C2 across voltage VC2, and the capacitor C3 across voltage VC3 are gradually increased to the stable ranges. In the present embodiment, in the pre-charge mode before the start-up mode, the voltage drop of the capacitor C1 is pre-charged to the second predetermined voltage Vpr, so as to reduce the inrush current and the ripple current of the output current (e.g. corresponding to the second current I2).

FIG. 6 is a circuit diagram of a resonant switching power conversion circuit according to another embodiment of the present invention. The switching converter 302 in this embodiment is similar to the switching converter 202 of fig. 2, and the difference is that the inductor L1 of the switching converter 302 is directly connected in series with the third capacitor (capacitor C3) to form the resonant tank 3021, and the inductor L2 of the switching converter 302 is directly connected in series with the second capacitor (capacitor C2) to form the resonant tank 3022. In one embodiment, in the first procedure, the switches Q1 to Q10 control the resonant tank 3021 and the first capacitor (capacitor C1) to be connected in series between the first power source and the second power source, and control the resonant tank 3022 to be connected in parallel with the second power source. On the other hand, in the second routine, the switches Q1 to Q10 control the resonant tank 3022 and the first capacitor (capacitor C1) to be connected in series between the second power supply and the ground potential, and control the resonant tank 3021 to be connected in parallel with the second power supply, and the switching converter 302 performs the power conversion between the first power supply and the second power supply by the above-described periodic operation and the resonant operation. The control details of the switches Q1 to Q10 can be found in the embodiment of fig. 2. The controller 301 of the present embodiment can be implemented by using the controller architecture of fig. 3 and 4, please refer to the detailed description of fig. 3 and 4.

FIG. 7 is a circuit diagram of a resonant switching power conversion circuit according to another embodiment of the present invention. The switching converter 402 in this embodiment is similar to the switching converter 202 of fig. 2, except that the switching converter 402 shares an inductor L coupled between the second power source and the switching node LX, and in the first procedure, the switches Q1-Q10 control the first capacitor (capacitor C1) and the third capacitor (capacitor C3) to be connected in series between the first power source and the second power source after being connected in series with the inductor L via the switching node LX, and control the second capacitor (capacitor C2) to be connected in parallel with the second power source after being connected in series with the inductor L via the switching node LX. On the other hand, in the second routine, the plurality of switches Q1 to Q10 control the second capacitor (capacitor C2) and the first capacitor (capacitor C1) to be connected in series with the inductor L between the second power source and the ground potential via the switching node LX, and control the third capacitor (capacitor C3) to be connected in series with the inductor L via the switching node LX and then connected in parallel with the second power source. In this embodiment, the first capacitor (capacitor C1), the second capacitor (capacitor C2), and the third capacitor (capacitor C3) perform the conversion between the first power source and the second power source by resonating with the inductor L. The control details of the switches Q1 to Q10 can be found in the embodiment of fig. 2. The controller 401 of the present embodiment can be implemented by using the controller architecture of fig. 3 and 4, please refer to the detailed description of fig. 3 and 4.

It should be noted that the capacitor and the inductor are operated in a resonant manner during the charging and discharging processes of the present embodiment, so that the surge current of the capacitor during the charging and discharging processes can be effectively reduced, and the zero current switching or the zero voltage switching can be realized by the resonant characteristic.

FIG. 8 is a circuit diagram of a resonant switching power conversion circuit according to another embodiment of the present invention. The switching converter 302a shown in fig. 8 may correspond to the switching converter 302 of fig. 6, specifically, in the present embodiment, in the 2-fold conversion mode, the switch Q1 of the switching converter 302a is constantly turned on (shown by short circuit), the switches Q2, Q3, Q8 to Q10 are constantly turned off, and the switches Q4 to Q7 are used to switch the second capacitor (capacitor C2), so that the second capacitor (capacitor C2) and the inductor L2 are connected in series between the first power source and the second power source in the first procedure, and after the second capacitor (capacitor C2) and the inductor L2 are connected in series in the second procedure, the second capacitor (capacitor C2) is connected in parallel to the second power source, so that a ratio of the first voltage V1 of the first power source to the second voltage V2 of the second power source is 2, wherein the second capacitor (capacitor C2) and the inductor L2 operate in a resonant manner to realize the power conversion between the first power source and the second power source. In this embodiment, since the switches Q2, Q3, and Q8 to Q10 are constantly off, at least one end of the resonant tank 3021a (the third capacitor (capacitor C3), the inductor L1) and the first capacitor (capacitor C1) are also constantly floating. The controller 301a of the present embodiment can be implemented by using the controller architecture of fig. 3 and 4, please refer to the detailed description of fig. 3 and 4.

Fig. 9 is a circuit diagram of a resonant switching power conversion circuit according to another embodiment of the invention. The switching converter 402a shown in fig. 9 can correspond to the switching converter 402 of fig. 7, specifically, in the present embodiment, in the 2-fold switching mode, the switch Q1 of the switching converter 402a is constantly turned on (shown as a short circuit), the switches Q2, Q3, Q8 to Q10 are constantly turned off, the switches Q4 to Q7 are used to switch the second capacitor (capacitor C2), so that in the first procedure, the second capacitor (capacitor C2) is controlled to be connected in series with the inductor L through the switching node LX before being connected in series between the first power source and the second power source, and in the second procedure, the second capacitor (capacitor C2) is controlled to be connected in parallel with the second power source after being connected in series with the inductor L through the switching node LX, in other words, the switches Q4 to Q7 in the second procedure, the second capacitor (capacitor C2) is controlled to be connected in series between the second power source and the ground potential through the switching node LX, so that the ratio between the first voltage V1 of the first power source and the second voltage V2 of the second power source is 2, wherein the second capacitor C2 operates in a resonant mode for switching between the first power source and the second power source. In this embodiment, since the switches Q2, Q3, and Q8 to Q10 are constantly off, at least one end of each of the first capacitor (capacitor C1) and the third capacitor (capacitor C3) is constantly floating. The controller 401a of the present embodiment can be implemented by using the controller architecture of fig. 3 and 4, please refer to the detailed description of fig. 3 and 4.

FIG. 10 is a circuit diagram of a resonant switching power conversion circuit according to another embodiment of the present invention. The switching converter 202a shown in fig. 10 can correspond to the switching converter 202 of fig. 2, specifically, in the present embodiment, in the 2-fold conversion mode, the switches Q4 and Q9 of the switching converter 202a are constantly turned on (shown as short-circuited), the switches Q3, Q5, Q6 and Q10 are constantly turned off, the switches Q1, Q2, Q7 and Q8 are used to switch the first capacitor (capacitor C1), so that in the first procedure, the first capacitor (capacitor C1) is controlled to be connected in series with the inductor L1 through the first switching node LX1 and then connected in parallel with the second power supply after being connected in series with the inductor L1 through the second switching node LX2, and in the second procedure, the first capacitor (capacitor C1) is controlled to be connected in series with the inductor L2 through the second switching node LX2 and then connected in parallel with the second power supply, in other words, the switches Q4 to Q7 are in the second procedure, the first capacitor (capacitor C1) is controlled to be connected in series with the inductor L2 and connected between the second power supply and the ground, so that the ratio of the first power supply voltage V1 to the second power supply V2 and the inductor L2 is switched between the first power supply voltage. In this embodiment, since the switches Q3, Q5, Q6, and Q10 are constantly off, at least one end of each of the third capacitor (capacitor C3) and the second capacitor (capacitor C2) is constantly floating. The controller 201a of the present embodiment can be implemented by using the controller architecture of fig. 3 and 4, please refer to the detailed description of fig. 3 and 4.

FIG. 11 is a circuit diagram of a resonant switching power conversion circuit according to another embodiment of the present invention. The switching converter 402b shown in fig. 11 may correspond to the switching converter 402 of fig. 7, in the embodiment, in the 3-fold conversion mode, the switch Q4 of the switching converter 402b is constantly turned on (shown by a short circuit), the switches Q5 and Q6 are constantly turned off, the switches Q1 to Q3 and Q7 to Q10 are used to switch the first capacitor (capacitor C1) and the third capacitor (capacitor C3), so as to control the first capacitor (capacitor C1), the third capacitor (capacitor C3) and the inductor L to be connected in series between the first power source and the second power source in the first procedure, and control the first capacitor (capacitor C1) and the third capacitor (capacitor C3) to be connected in series with the inductor L and then to be connected in parallel with the second power source in the second procedure, so that a ratio of the first voltage V1 of the first power source to the second voltage V2 of the second power source is 3, where the first capacitor (capacitor C1) and the third capacitor (capacitor C3) and the inductor L operate in a resonant manner to realize the conversion between the first power source and the second power source. In this embodiment, since the switches Q5 and Q6 are constantly off, one end of the second capacitor (capacitor C2) is also constantly floating. The controller 401b of the present embodiment can be implemented by using the controller architecture of fig. 3 and 4, please refer to the detailed description of fig. 3 and 4.

FIG. 12 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention. The switching converter 202b shown in fig. 12 may correspond to the switching converter 202 of fig. 2, and the operations of the switches thereof are similar to the switching converter 402b, with the difference that in the first procedure, the first capacitor (capacitor C1), the third capacitor (capacitor C3) and the inductor L1 of the switching converter 202b are connected in series between the first power source and the second power source, and in the second procedure, the third capacitor (capacitor C3) and the first capacitor (capacitor C1) are connected in series with the inductor L1 and the inductor L2, respectively, and then connected in parallel with the second power source, so that the ratio of the first voltage V1 to the second voltage V2 is 3. The details of the operation of the switch can be found in the embodiment of fig. 11. The controller 201b of the present embodiment can be implemented by using the controller architecture of fig. 3 and 4, please refer to the detailed description of fig. 3 and 4.

In fig. 8 to 12, the switches and the elements corresponding to the switch and the element arrangement of fig. 6, 7 and 2 are arranged such that the ratio of the first voltage V1 to the second voltage V2 can be set to several different multiples by switching some switches to be constantly turned on, the other switches to be constantly turned off, and the other switches according to a desired mode. In addition, fig. 8 to 12 are equivalent circuit diagrams showing the embodiments of fig. 6, 7 and 2, wherein the switch that is constantly off and the capacitor that is constantly floating are omitted in the drawings to simplify the drawings.

FIG. 13 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention. The switching converter 502 shown in fig. 13 is similar to the switching converter 202 shown in fig. 2, in the embodiment, the inductors L1 and L2 of the switching converter 502 have mutual inductance, so that the inductor L1 current IL1 and the inductor L2 current IL2 of the switching converter 502 can have better current balance therebetween, and simultaneously, the capacitors C3 and C2 can have better voltage balance therebetween. The controller 501 of the present embodiment can be implemented by using the controller architecture of fig. 3 and 4, please refer to the detailed description of fig. 3 and 4.

In one embodiment, the inductors L1 and L2 may be configured as mutual inductors (or transformers, for example), or as a transformer (such as transformer 5021).

FIG. 14 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention. In one embodiment, the resonant switching power converter circuit 60 includes a first switching converter 602 and a second switching converter 603, the first switching converter 602 and the second switching converter 603 are coupled in parallel between the first power source and the second power source, in this embodiment, the first switching converter 602 and the second switching converter 603 correspond to the switching converter 302 of fig. 6, for example, in this embodiment, the output power can be increased or the ripple current and the ripple current can be reduced by a plurality of switching converters operating in parallel. The term "parallel connection" of the switching converters means that the input ends of the switching converters are electrically connected to each other, for example, the first power supply, and the output ends of the switching converters are electrically connected to each other, for example, the second power supply.

In one embodiment, the first switching converter 602 and the second switching converter 603 switch the corresponding switches in each switching converter with opposite phases to each other, so as to perform power conversion in an interleaved manner, specifically, as shown in fig. 14, the control signals GA and GB of the switches Q1 to Q10 of the first switching converter 602 are in phase with the switching converter 302 of fig. 6, and the control signals GA and GB of the switches Q11 to Q20 of the second switching converter 603 are in anti-phase with the switching converter 302 of fig. 6 (and thus are also in anti-phase with the first switching converter 602).

The first switching converter 602 and the second switching converter 603 include inductors L1, L2, L11, and L12, and are connected in series with capacitors C3, C2, C13, and C12 to form

resonant tanks

6021, 6022, 6031, and 6032, respectively. In the present embodiment, the first switching converter 602 and the second switching converter 603 are operated in an interleaved manner to perform power conversion, and the first switching converter 602 and the second switching converter 603 are respectively similar to the switching converter 302 in fig. 6, and perform power conversion in a resonant manner. The controller 601 of the present embodiment can be implemented by using the controller architecture of fig. 3 and 4, please refer to the detailed description of fig. 3 and 4. As shown in fig. 14, the controller 601 of the present embodiment is coupled to the first power source, the second power source, the first switch (e.g., the switch Q1 and the switch Q11), and a node between the first switch and the seventh switch (e.g., a node between the switch Q1 and the switch Q7, and a node between the switch Q11 and the switch Q17).

FIG. 15 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention. The resonant switching power conversion circuit 70 of fig. 15 is similar to the resonant switching power conversion circuit 60 of fig. 14, and the resonant switching power conversion circuit 70 includes a first switching converter 702 and a second switching converter 703, which differ in that the first switching converter 702 shares an inductor L1, and the second switching converter 703 shares an inductor L11, and is connected in series with the inductor L1 after the capacitors C3 and C2 are connected in parallel in a manner similar to the embodiment of fig. 7, and is connected in series with the inductor L11 after the capacitors C13 and C12 are connected in parallel in a manner similar to the embodiment of fig. 7. Like the resonant switching power conversion circuit 60 of fig. 14, the present embodiment also performs power conversion by operating the first switching converter 702 and the second switching converter 703 in an interleaved manner, and the first switching converter 702 and the second switching converter 703 are respectively similar to the switching converter 402 of fig. 7, and perform power conversion in a resonant manner. The controller 701 of the present embodiment can be implemented by using the controller architecture of fig. 3 and 4, please refer to the detailed description of fig. 3 and 4. As shown in fig. 15, the controller 701 of the present embodiment is coupled to the first power source, the second power source, the first switch (e.g., the switch Q1 and the switch Q11), and a node between the first switch and the seventh switch (e.g., a node between the switch Q1 and the switch Q7, and a node between the switch Q11 and the switch Q17).

FIG. 16 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention. The resonant switching power conversion circuit 80 of fig. 16 is similar to the resonant switching power conversion circuit 60 of fig. 14, and the resonant switching power conversion circuit 80 includes a first switching converter 802 and a second switching converter 803, and the difference is that the inductances L1, L2, L11, L12 of the first switching converter 802 and the second switching converter 803 are not directly connected in series with the capacitances C3, C2, C13, C12, respectively, but are connected in series with the capacitances C3, C2, C13, C12, respectively, via a first switching node LX1, a second switching node LX2, a first switching node LX11, and a second switching node LX 12. Like the resonant switching power conversion circuit 60 of fig. 14, the present embodiment also operates the first switching converter 802 and the second switching converter 803 in an interleaved manner to perform power conversion, and the first switching converter 802 and the second switching converter 803 are respectively similar to the switching converter 202 of fig. 2, and perform power conversion in a resonant manner. The controller 801 of the present embodiment can be implemented by using the controller architecture of fig. 3 and 4, please refer to the detailed description of fig. 3 and 4. As shown in fig. 16, the controller 801 of the present embodiment is coupled to the first power source, the second power source, the first switch (e.g., the switch Q1 and the switch Q11), and a node between the first switch and the seventh switch (e.g., a node between the switch Q1 and the switch Q7, and a node between the switch Q11 and the switch Q17).

FIG. 17 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention. The resonant switching power conversion circuit 90 of fig. 17 is similar to the resonant switching power conversion circuit 80 of fig. 16, and the inductors L1, L2, L11, and L12 of the resonant switching power conversion circuit 90 have mutual inductance, so that the inductor L1 current IL1, the inductor L2 current IL2, the inductor L11 current IL11, and the inductor L12 current IL12 of the resonant switching power conversion circuit 90 can have better current balance, and the capacitors C3, C2, C13, and C12 can have better voltage balance. In one embodiment, the resonant switching power conversion circuit 90 may be configured to have mutual inductance between all of the inductors L1, L2, L11, and L12, or only some of the inductors, as required. In one embodiment, the inductors L1, L2, L11, and L12 may be configured as at least one transformer. The controller 901 of the present embodiment can be implemented by using the controller architecture of fig. 3 and fig. 4, please refer to the detailed description about fig. 3 and fig. 4. As shown in fig. 17, the controller 901 of the present embodiment is coupled to the first power source, the second power source, the first switch (e.g., the switch Q1 and the switch Q11), and a node between the first switch and the seventh switch (e.g., a node between the switch Q1 and the switch Q7, and a node between the switch Q11 and the switch Q17).

FIG. 18A is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention. The resonant switching power converter circuit 100 shown in fig. 18A includes a first switching converter 1002, a second switching converter 1003, an upper capacitor (capacitor C21), and a plurality of upper switches (e.g., switches Q21, Q28), wherein the first switching converter 1002 and the second switching converter 1003 may correspond to the switching converter 302 of fig. 6, for example. In one aspect, the resonant switching power converter circuit 100 shown in fig. 18A is a resonant switching power converter circuit configured to have more layers based on the switching converter 302 of fig. 6, for example, specifically, the upper layer capacitor (capacitor C21), the plurality of upper layer switches (switches Q21, Q28), the first switching converter 1002 and the second switching converter 1003 are coupled to each other in a basic topology, as shown in fig. 18B, the "basic topology" refers to a basic coupling relationship between the upper layer capacitor (capacitor C21), the plurality of upper layer switches (switches Q21, Q28, for example), the first switching converter 1002 and the second switching converter 1003 in one embodiment, which will be described in detail later. The controller 1001 of the present embodiment can be implemented by using the controller architecture of fig. 3 and 4, please refer to the detailed description of fig. 3 and 4. As shown in fig. 18A, in an embodiment, the upper switch (e.g., the switch Q21) is turned off when the controller 1001 is in the precharge mode, in other words, the controller 1001 of this embodiment is coupled to a node between the first power source, the second power source, the upper switch (e.g., the switch Q21) and the first switch (e.g., the switch Q1) of the second switching converter 1003.

In one embodiment, according to the basic topology described above, the input terminal of the first switching converter 1002 (corresponding to the first switching converter 1002B, fig. 18B) and one terminal of the upper capacitor (capacitor C21) are electrically connected to each other, the input terminal of the second switching converter 1003 (corresponding to the second switching converter 1003B, fig. 18B) and the other terminal of the upper capacitor (capacitor C21) are electrically connected to each other, and further, the output terminal of the first switching converter 1002, the output terminal of the second switching converter 1003 and the second power source are electrically connected to each other.

In a first procedure (e.g., when the control signal GA is disabled and the control signal GB is enabled), the switches (e.g., the switches Q21 and Q28) of the upper layer switch 1002 and the switches (e.g., the switches Q11 to Q20) of the first switch converter 1002 control the upper layer capacitor (e.g., the capacitor C21) to be connected in series with the first switch converter 1002 and establish at least one current path between the first power source and the second power source, and the switches (e.g., the switches Q21 and Q28) of the upper layer switch 1003 and the switches (e.g., the switches Q1 to Q10) of the second switch converter 1003 control the upper layer capacitor (e.g., the capacitor C21) to be disconnected from the second switch converter 1003 and control the second switch converter 1003 to establish at least one current path between the second power source and the ground potential.

On the other hand, in the second procedure (for example, when the control signal GA is enabled and the control signal GB is disabled), the switches (Q1 to Q10) of the upper switches (Q21, Q28) and the second switching converter 1003 control the second switching converter 1003 and the upper capacitor (capacitor C21) to be connected in series between the second power source and the ground potential, and at least one current path is established between the second power source and the ground potential, and the switches (Q11 to Q20) of the upper switches (Q21, Q28) and the first switching converter 1002 control the upper capacitor (capacitor C21) and the first switching converter 1002 to be disconnected, and control the first switching converter 1002 to establish at least one current path between the second power source and the ground potential.

The current paths are, for example, current paths established by correspondingly turned-on switches when the control signal GA is enabled or when the control signal GB is enabled.

The first switching converter 1002 and the second switching converter 1003 are also configured with resonant slots, i.e.,

resonant slots

10021, 10022, 10031, 10032, as in the embodiment of fig. 6, so that the first power source and the second power source are switched by the

resonant slots

10021, 10022, 10031, 10032 in a resonant manner.

In this embodiment, the ratio of the first voltage V1 to the second voltage V2 shown in fig. 18A is 8. In detail, in steady state, the voltage across the capacitor C21 is 4 × V2, the voltages across the capacitors C1 and C11 (both corresponding to the first capacitor in the foregoing embodiment) are 2 × V2, and the voltages across the capacitors C3 and C13 (both corresponding to the third capacitor in the foregoing embodiment) and the capacitors C2 and C12 (both corresponding to the second capacitor in the foregoing embodiment) are V2.

With continuing reference to FIG. 18B, according to the present invention, the number of stages of the pipeline resonant switching power conversion circuit can be recursively expanded through the basic topology of FIG. 18B, thereby achieving a higher conversion ratio between the first voltage and the second voltage. As shown in fig. 18B, any pipeline resonant switching power conversion circuit with the basic topology shown in fig. 18B may be used to replace the first switching converter 1002 and the second switching converter 1003 (for example, the first switching converter 1002B and the second switching converter 1003B in the figure may correspond to N layers of pipeline resonant switching power conversion circuits, where N is an integer greater than or equal to 2), so as to obtain a pipeline resonant switching power conversion circuit with a higher number of layers, that is, the pipeline resonant switching power conversion circuit 100B will become an N +1 layer of pipeline resonant switching power conversion circuit.

Specifically, for example, if the pipeline resonant switching power conversion circuit 100 of fig. 18A is substituted into the first switching converter 1002B and the second switching converter 1003B of fig. 18B, the pipeline resonant switching power conversion circuit 100B of fig. 18B is configured as a pipeline resonant switching power conversion circuit of 16.

In this embodiment (16.

FIG. 19 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention. The resonant switching power conversion circuit 110 shown in fig. 19 is similar to the resonant switching power conversion circuit 100 shown in fig. 18A, except that the first switching converter 1102 shares the inductor L11, and the second switching converter 1103 shares the inductor L1, and is connected in series with the inductor L1 after the capacitors C3 and C2 are connected in parallel in a manner similar to the embodiment shown in fig. 7, and is connected in series with the inductor L11 after the capacitors C13 and C12 are connected in parallel in a manner similar to the embodiment shown in fig. 7. Like the resonant switching power conversion circuit 100 in fig. 18A, the present embodiment also operates the first switching converter 1102 and the second switching converter 1103 in an interleaved manner to perform power conversion, and the first switching converter 1102 and the second switching converter 1103 are respectively similar to the switching converter 402 in fig. 7 to perform power conversion in a resonant manner. The controller 1101 of the present embodiment can be implemented by using the controller architecture of fig. 3 and 4, please refer to the detailed description of fig. 3 and 4. As shown in fig. 19, in an embodiment, the controller 1101 is an upper switch (e.g., the switch Q21) in the precharge mode, that is, the controller 1101 of the embodiment is coupled to a node between the first power source, the second power source, the upper switch (e.g., the switch Q21) and the first switch (e.g., the switch Q1) of the second switching converter 1103.

FIG. 20 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention. The resonant switching power conversion circuit 120 shown in fig. 20 is similar to the resonant switching power conversion circuit 100 shown in fig. 18A, except that the inductances L1, L2, L11, L12 of the first switching converter 1202 and the second switching converter 1203 are not directly connected in series with the capacitances C3, C2, C13, C12, respectively, but are connected in series with the capacitances C3, C2, C13, C12 through the first switching node LX1, the second switching node LX2, the first switching node LX11, and the second switching node LX12, respectively, in other words, the resonant switching power conversion circuit 120 performs switching operation in a manner similar to the resonant switching power conversion circuit 100, and further performs conversion between the first power supply and the second power supply in a resonant manner as in the embodiment of fig. 2 through the inductances L1, L2, L11, L12 and the corresponding capacitances, and in this embodiment, the ratio of the first voltage V1 to the second voltage V2 is also 8. The controller 1201 of the present embodiment can be implemented by using the controller architecture of fig. 3 and 4, please refer to the detailed description about fig. 3 and 4. As shown in fig. 20, in an embodiment, the one that the controller 1201 is turned off in the precharge mode is an upper switch (e.g., the switch Q21), in other words, the controller 1201 of the embodiment is coupled to a node between the first power source, the second power source, the upper switch (e.g., the switch Q21) and the first switch (e.g., the switch Q1) of the second switching converter 1203.

FIG. 21 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention. The resonant switching power conversion circuit 130 of fig. 21 is similar to the resonant switching power conversion circuit 120 of fig. 20, and the inductors L1, L2, L11, and L12 of the resonant switching power conversion circuit 130 have mutual inductance, so that the inductor L1 current IL1, the inductor L2 current IL2, the inductor L11 current IL11, and the inductor L12 current IL12 of the resonant switching power conversion circuit 130 can have better current balance, and the capacitors C3, C2, C13, and C12 can have better voltage balance. In one embodiment, the resonant switching power conversion circuit 130 may be configured to have mutual inductance between all of the inductors L1, L2, L11, and L12, or only some of the inductors, as required. In one embodiment, the inductors L1, L2, L11, and L12 may be configured as at least one transformer. The controller 1301 of the present embodiment can be implemented by using the controller architectures of fig. 3 and fig. 4, please refer to the detailed description about fig. 3 and fig. 4. As shown in fig. 21, in an embodiment, the upper switch (e.g., the switch Q21) is turned off when the controller 1301 is in the precharge mode, in other words, the controller 1301 of the embodiment is coupled to a node between the first power source, the second power source, the upper switch (e.g., the switch Q21), and the first switch (e.g., the switch Q1) of the second switching converter 1303.

FIG. 22 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention. As shown in fig. 22, the resonant switching power conversion circuit 140 includes resonant capacitors C1 and C3, at least one non-resonant capacitor C2, switches Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, Q10, resonant inductors L1 and L2, and a controller 1401. The controller 1401 of the present embodiment can be implemented by using the controller architecture of fig. 3 and 4, please refer to the detailed description of fig. 3 and 4. As shown in fig. 22, in an embodiment, the first switch (e.g., the switch Q1) is turned off when the controller 1401 is in the precharge mode, in other words, the controller 1401 of the embodiment is coupled to a node between the first power source, the second power source, the first switch (e.g., the switch Q1), and the first resonant capacitor (e.g., the resonant capacitor C1).

In one embodiment, in the precharge mode, the control circuit of the controller 1401 generates the precharge operation signal to perform at least one of the following operations: (1) Turning on the switch Q6, and controlling the pre-charge circuit to charge the voltage drop of the first resonant capacitor (e.g., the resonant capacitor C1) to a first preset voltage; (2) The switch Q2 and the switch Q8 are conducted, and the pre-charging circuit is controlled to charge the voltage drop of the non-resonant capacitor C2 to a second preset voltage; or (3) turning on the switch Q2, the switch Q3, and the switch Q10, and controlling the pre-charge circuit to charge the voltage drop of the second resonant capacitor (e.g., the resonant capacitor C3) to the third predetermined voltage. In one embodiment, the first predetermined voltage is three times the target voltage of the second voltage V2 of the second power source, the second predetermined voltage is two times the target voltage of the second voltage V2, and the third predetermined voltage is the target voltage of the second voltage V2.

As shown in fig. 22, the controller 1401 is configured to generate a first operation signal GA and a second operation signal GB for the resonant voltage conversion mode, so as to respectively correspond to a first resonant procedure and a second resonant procedure, and operate the corresponding switches Q1-Q10 to switch the electrical connection relationship between the corresponding resonant capacitors C1 and C3 and the non-resonant capacitor C2. The resonant switching power conversion circuit 140 includes at least one resonant tank, such as resonant tanks 1402 and 1403, in which the resonant tank 1402 has a resonant capacitor C1 and a resonant inductor L1 connected in series, and the resonant tank 1403 has a resonant capacitor C3 and a resonant inductor L2 connected in series. The switches Q1-Q10 are correspondingly coupled to at least one resonant tank 1402, 1403, and respectively switch the electrical connection relationship of the corresponding resonant tank 1402, 1403 according to the corresponding first operation signal GA and the second operation signal GB to correspond to the first resonant procedure and the second resonant procedure in the resonant voltage conversion mode. In the first resonance process, the corresponding resonance tank 1402, 1403 is resonance charged, and in the second resonance process, the corresponding resonance tank 1402, 1403 is resonance discharged. The at least one non-resonant capacitor C2 is coupled to the at least one resonant tank 1402, 1403, and in the resonant voltage conversion mode, the first operation signal GA and the second operation signal GB switch the electrical connection relationship between the non-resonant capacitor C2 and the at least one resonant tank 1402, 1403. The voltage across the non-resonant capacitor C2 is maintained at a fixed ratio to the first voltage V1 of the first power supply, for example, one-half of the first voltage V1 in this embodiment. The resonant switching power conversion circuit 140 operates in a start mode after the pre-charge mode is ended, and operates in a resonant voltage conversion mode after the start mode is ended, wherein the first resonant procedure and the second resonant procedure are repeatedly and alternately sequenced to convert the first power into the second power or convert the second power into the first power. In the resonant voltage conversion mode, the first operation signal GA and the second operation signal GB are respectively switched to the on level for an on period, and the on periods of the plurality of segments are not overlapped with each other, so that the first resonant process and the second resonant process are not overlapped with each other.

In the first resonance process, according to the first operation signal GA, the switches Q1, Q3, Q5, Q8, and Q9 are turned on, and the switches Q2, Q4, Q6, Q7, and Q10 are turned off, so that the resonant capacitor C1 and the resonant inductor L1 of the resonant tank 1402 are connected in series between the first power source and the second power source, and the non-resonant capacitor C2 and the resonant capacitor C3 and the resonant inductor L2 of the resonant tank 1403 are connected in series between the ground potential and the second power source, thereby charging the resonant capacitors C1 and C3 and discharging the non-resonant capacitor C2. In the second resonance process, the switches Q2, Q4, Q6, Q7, Q10 are turned on and the switches Q1, Q3, Q5, Q8, Q9 are turned off according to the second operation signal GB, so that the non-resonant capacitor C2, the resonant capacitor C1 of the resonant tank 1402, and the resonant inductor L1 are connected in series between the ground potential and the second power source, and the resonant capacitor C3 of the resonant tank 1403 and the resonant inductor L2 are connected in series between the ground potential and the second power source, thereby discharging the resonant capacitors C1, C3 and charging the non-resonant capacitor C2.

The operation of the resonant switching power conversion circuit 140 having the resonant slots 1402 and 1403 shown in fig. 22 is well known to those skilled in the art and will not be described herein. In one embodiment, the resonant switching power converter circuit 140 of the present invention can be hot-plugged (hot swap) from the whole circuit after the first power.

Fig. 23 is a circuit diagram of a resonant switching power conversion circuit according to still another embodiment of the invention. As shown in fig. 23, the resonant switching power converter circuit 150 of the present invention includes capacitors C1 to C3, switches Q1 to Q10, and inductors L1 to L3. The switches Q1-Q3 are respectively connected in series with corresponding capacitors C1-C3, and the capacitors C1-C3 are respectively connected in series with corresponding inductors L1-L3. It should be noted that the number of capacitors in the power conversion circuit of the present invention is not limited to three in the present embodiment, and may also be two or more, and the number of inductors is not limited to three in the present embodiment, and may also be two or more.

The switches Q1-Q10 can switch the electrical connection relationship between the corresponding capacitors C1-C3 and the inductors L1-L3 according to the corresponding operation signals. In the first process, the switches Q1-Q4 are turned on and the switches Q5-Q10 are turned off, so that the capacitors C1-C3 and the inductors L1-L3 are connected in series between the first power supply and the second power supply to form a first current path for performing the charging process. In the second procedure, the inductors L1-L3 can be used as discharging inductors, the switches Q5-Q10 are turned on, the switches Q1-Q4 are turned off, so that the capacitor C1 and the corresponding inductor L1 are connected in series between the second power supply and the ground potential, the capacitor C2 and the corresponding inductor L2 are connected in series between the second power supply and the ground potential, and the capacitor C3 and the corresponding inductor L3 are connected in series between the second power supply and the ground potential to form a plurality of second current paths for performing the discharging procedure. It should be noted that the first process and the second process are performed alternately, not simultaneously, in different time periods to convert the first power source into the second power source or to convert the second power source into the first power source. The first program and the second program are repeatedly and alternately ordered to convert the first power supply into the second power supply or convert the second power supply into the first power supply. In the present embodiment, the dc bias of each of the capacitors C1, C2, and C3 is the second voltage V2 of the second power supply, so the capacitors C1, C2, and C3 in the present embodiment need to withstand a lower rated voltage, and thus a smaller capacitor can be used.

In one embodiment, the first program has a first resonant frequency, and the second program has a second resonant frequency. In a preferred embodiment, the first resonant frequency is the same as the second resonant frequency.

In one embodiment, the voltage conversion ratio of the first power source and the second power source of the resonant switching power conversion circuit 150 may be 4:1, 3:1, or 2:1. It should be noted that the embodiment is the power conversion circuit 4:1, but the power conversion circuit of this embodiment can be changed to the power conversion circuit 3:1 by controlling the switches Q1-Q10 to be turned off or on, for example, the switch Q7 is turned on constantly, and the switches Q4 and Q10 are turned off constantly, so that the power conversion circuit 3:1 can be changed to the power conversion circuit 2:1 in the same manner. The controller 1501 of the present embodiment can be implemented using the controller architecture of fig. 3 and 4, please refer to the detailed description of fig. 3 and 4. As shown in fig. 23, in an embodiment, the controller 1501 is a first switch (e.g., the switch Q1) that is turned off in the precharge mode, in other words, the controller 1501 of the embodiment is coupled to a node between the first power source, the second power source, the first switch (e.g., the switch Q1), and the fifth switch (e.g., the switch Q5).

FIG. 24 is a circuit diagram of a resonant switching power conversion circuit according to another embodiment of the present invention. The difference between this embodiment and the previous embodiment is that the capacitors of this embodiment share a charging inductor or a discharging inductor, so that only one charging inductor and one discharging inductor are needed no matter how many capacitors are, and the number of inductors can be further reduced. As shown in fig. 24, the resonant switching power converter circuit 160 of the present invention includes capacitors C1 to C3, switches Q1 to Q10, and inductors L1 to L2. Switches Q1-Q3 are connected in series with corresponding capacitors C1-C3, respectively, and switch Q4 is connected in series with inductor L1. It should be noted that the number of capacitors in the resonant switching power conversion circuit of the present invention is not limited to three in this embodiment, and may be two or more than four.

The switches Q1 to Q10 can switch the electrical connection relationship between the corresponding capacitors C1 to C3 and the inductors L1 and L2 according to the corresponding operation signals. In the first process, the switches Q1-Q4 are turned on and the switches Q5-Q10 are turned off according to the first operation signal GA, so that the capacitors C1-C3 are connected in series with each other and then connected in series with the inductor L1 between the first power supply and the second power supply to form a first current path for performing the charging process. In the second process, the switches Q5 to Q10 are turned on and the switches Q1 to Q4 are turned off according to the second operation signal GB, so that the capacitors C1 to C3 are connected in parallel and then connected in series with the inductor L2 between the second power source and the ground potential to form a plurality of second current paths for performing the discharging process. It should be noted that the first process and the second process are performed alternately, not simultaneously, in different time periods to convert the first power source into the second power source or to convert the second power source into the first power source. In the present embodiment, the dc bias of each of the capacitors C1, C2, and C3 is the second voltage V2 of the second power supply, so the capacitors C1, C2, and C3 in the present embodiment need to withstand a lower rated voltage, and thus a smaller capacitor can be used.

In one embodiment, the first program has a first resonant frequency, and the second program has a second resonant frequency. In a preferred embodiment, the first resonant frequency is the same as the second resonant frequency. In another embodiment, the first resonant frequency is different from the second resonant frequency. In one embodiment, the inductance of the inductor L1 is equal to the inductance of the inductor L2. In another embodiment, the inductance of the inductor L1 is different from the inductance of the inductor L2. The controller 1601 of the present embodiment can be implemented by using the controller architecture of fig. 3 and 4, please refer to the detailed description of fig. 3 and 4. As shown in fig. 24, in an embodiment, the controller 1601 is a first switch (e.g., the switch Q1) that is turned off in the precharge mode, in other words, the controller 1601 of this embodiment is coupled to a node between the first power source, the second power source, the first switch (e.g., the switch Q1), and the fifth switch (e.g., the switch Q5).

FIG. 25 is a circuit diagram of a resonant switching power converter circuit according to another embodiment of the present invention. In this embodiment, the charging inductor and the discharging inductor may be the same inductor L1, and such an arrangement may further reduce the number of inductors. As shown in fig. 25, the resonant switching power converter circuit 170 of the present invention includes capacitors C1 to C3, switches Q1 to Q10, and an inductor L1. Switches Q1-Q3 are connected in series with corresponding capacitors C1-C3, respectively, and switch Q4 is connected in series with inductor L1. It should be noted that the number of capacitors in the resonant switching power conversion circuit of the present invention is not limited to three in this embodiment, and may be two or more than four.

In the present embodiment, the charging inductor and the discharging inductor are a single same inductor L1, and in the second procedure, the switches Q1 to Q10 are switched to connect the capacitors C1 to C3 in parallel to each other and then connect the same inductor L1 in series. The term "charging inductance" and "discharging inductance" refer to a single inductance L1, which means that in the first procedure (also referred to as charging procedure) and the second procedure (also referred to as discharging procedure), the inductance L1 current IL1 and the inductance L2 current IL2 respectively only flow through a single inductance L1, but do not flow through other inductance elements.

The switches Q1 to Q10 can switch the electrical connection relationship between the corresponding capacitors C1 to C3 and the inductor L1 according to the corresponding operation signals. In the first process, the switches Q1-Q4 are turned on and the switches Q5-Q10 are turned off according to the first operation signal GA, so that the capacitors C1-C3 are connected in series with each other and then connected in series with the inductor L1 between the first power supply and the second power supply to form a first current path for performing the charging process. In the second process, the switches Q5 to Q10 are turned on and the switches Q1 to Q4 are turned off according to the second operation signal GB, so that the capacitors C1 to C3 are connected in parallel to each other and then connected in series with the inductor L1 between the second power source and the ground potential to form a plurality of second current paths for performing the discharging process. It should be noted that the first and second processes are performed alternately and repeatedly, but not simultaneously, in different time periods to convert the first power source into the second power source or to convert the second power source into the first power source. In the present embodiment, the dc bias of each of the capacitors C1 to C3 is the second voltage V2 of the second power supply, so the capacitors C1 to C3 in the present embodiment need to withstand a lower rated voltage, and thus a smaller capacitor can be used.

In one embodiment, the voltage conversion ratio of the first power source and the second power source of the resonant switching power conversion circuit 170 may be 4:1, 3:1 or 2:1.

In one embodiment, the voltage conversion ratio of the resonant switching power conversion circuit 170 can be flexibly adjusted, for example, in the first and second processes, the voltage conversion ratio of the resonant switching power conversion circuit 170 can be adjusted to 3:1 by selectively turning on the switch Q7 and selectively turning off the switches Q10 and Q4. Similarly, for example, if the switch Q6 is selected to be constantly on and the switches Q9, Q3, Q7, Q10, and Q4 are selected to be constantly off, the voltage conversion ratio of the resonant switching power converter circuit 170 can be adjusted to 2:1. The controller 1701 in this embodiment can be implemented using the controller architecture of fig. 3 and 4, as described in detail with reference to fig. 3 and 4. As shown in fig. 25, in an embodiment, the controller 1701 is a first switch (e.g., the switch Q1) that is turned off in the pre-charge mode, in other words, the controller 1701 of the embodiment is coupled to a node between the first power source, the second power source, the first switch (e.g., the switch Q1), and the fifth switch (e.g., the switch Q5).

The present invention provides a resonant switching power conversion circuit, which can achieve a pre-charge operation mode and a hot plug function by using the existing switch through a special circuit design, can achieve a start operation by using the existing power stage element, does not need an additional front-end dc-dc converter for start control, can use fewer elements and save space, can improve power conversion efficiency without power loss of the front-end dc-dc converter, can reduce surge current, can support soft-start (soft-start), and can support parallel operation for a multi-phase Resonant Switching Capacitive Converter (RSCC).

The present invention has been described with respect to the preferred embodiments, but the above description is only for the purpose of facilitating the understanding of the present invention by those skilled in the art, and is not intended to limit the broadest scope of the present invention. The embodiments described are not limited to single use, but may be used in combination, for example, two or more embodiments may be combined, and some components in one embodiment may be substituted for corresponding components in another embodiment. Furthermore, equivalent variations and combinations may be considered by those skilled in the art within the spirit of the present invention, and for example, the term "processing or computing or generating an output result based on a signal" is not limited to the term "processing or computing or generating an output result based on a signal", and includes, if necessary, performing voltage-to-current conversion, current-to-voltage conversion, and/or scaling on the signal, and then processing or computing the signal based on the converted signal to generate an output result. It is understood that equivalent variations and combinations, not necessarily all illustrated, will occur to those of skill in the art, which combinations are not necessarily intended to be limiting. Therefore, the scope of the present invention should be construed to include all such and other equivalent variations.

Claims

1. A resonant switching power conversion circuit for converting a first power to a second power or vice versa, the resonant switching power conversion circuit comprising:

at least one switching converter;

a control circuit for controlling the switching converter; and

a pre-charge circuit coupled between the control circuit and the at least one switching converter;

wherein the switching converter comprises:

a plurality of capacitors;

a plurality of switches, which are correspondingly coupled with the plurality of capacitors and controlled by the control circuit, and are used for switching the electrical connection relation of the corresponding capacitors;

at least one first inductor connected in series with at least one of the capacitors; and

at least one second inductor connected in series with at least one of the capacitors;

the control circuit is coupled to the first power supply, the second power supply and the plurality of switches, and is configured to control a first switch of the plurality of switches to control an electrical connection relationship between the first power supply and a first capacitor of the plurality of capacitors when the switching converter operates in a pre-charge mode, and to control the other switches to control the pre-charge circuit to charge a voltage drop of at least one of the plurality of capacitors to a predetermined voltage when the voltage drop of the at least one of the plurality of capacitors is lower than the predetermined voltage;

wherein, the first switch is electrically connected between the first power supply and the first capacitor;

in a starting mode, a first operation signal and at least one second operation signal are respectively used for correspondingly operating the switches so as to switch the electrical connection relation of the capacitors corresponding to the switches, so that the resonant switching type power conversion circuit is operated in the starting mode after the pre-charging mode is finished;

in the start mode, the first operating signal and the at least one second operating signal are respectively switched to a conducting level for a conducting period, and the conducting periods of the segments are not overlapped with each other, wherein the time lengths of the conducting periods of the segments are gradually increased;

in a resonant voltage conversion mode, the first operation signal and the at least one second operation signal are respectively used for correspondingly operating the switches to switch the electrical connection relation of the capacitors corresponding to the switches, so that the resonant switching power conversion circuit is operated in the resonant voltage conversion mode after the start mode is finished to convert the first power supply into the second power supply or convert the second power supply into the first power supply;

in the resonant voltage conversion mode, the first operating signal and the at least one second operating signal are respectively switched to the conducting level for a conducting period, and the conducting periods are not overlapped with each other, so that a first program and at least one second program of the resonant voltage conversion mode are not overlapped with each other;

wherein, in the first procedure, the plurality of switches are controlled to be switched by the first operation signal, so that the plurality of capacitors and the at least one first inductor are connected in series between the first power supply and the second power supply to form a first current path;

in the at least one second program, the switches are controlled by the at least one second operation signal, so that each capacitor and the corresponding second inductor are connected in series between the second power supply and a ground potential, and a plurality of second current paths are formed at the same time or alternately;

the first program and the at least one second program are repeatedly and alternately sequenced to convert the first power source into the second power source or convert the second power source into the first power source.

2. The resonant switching power converter circuit of claim 1, wherein the predetermined voltage is a target voltage of the second power source.

3. The resonant switching power converter circuit of claim 1, wherein the predetermined voltage is a positive integer multiple of a target voltage of the second power source.

4. The resonant switching power converter circuit of claim 1, wherein the pre-charge circuit comprises:

a current source for generating a pre-charge current; and

and a pre-charge switch circuit coupled between the current source and the plurality of switches except the first switch, wherein in the pre-charge mode, the control circuit controls the pre-charge switch circuit and the plurality of switches except the first switch to control the electrical connection relationship between the current source and the at least one of the plurality of capacitors, and further charges the voltage drop of the at least one of the plurality of capacitors to the preset voltage according to the pre-charge current.

5. The resonant switching power converter circuit of claim 1, wherein the control circuit comprises:

a duty ratio determining circuit for comparing a ramp-up voltage of a ramp-up node with a periodic waveform signal to generate a duty ratio signal;

a duty ratio distribution circuit for generating the first operation signal and the at least one second operation signal according to the duty ratio signal; and

a step-up voltage generating circuit coupled to the duty ratio determining circuit for generating the step-up voltage of the step-up node in the start mode;

the gradually rising voltage of the gradually rising node gradually rises in the start mode, so that the duty ratio of the first operation signal and the duty ratio of the at least one second operation signal correspondingly gradually rise.

6. The resonant switching power converter circuit of claim 1, wherein in the precharge mode, the control circuit controls a conduction level of the first switch such that a precharge current flows from the first power source to the at least one of the plurality of capacitors through the first switch to charge a voltage drop of the at least one of the plurality of capacitors to the predetermined voltage.

7. The resonant switching power converter circuit of claim 1, wherein the first operation signal controls the switching of the plurality of switches to connect at least one of the plurality of capacitors in parallel with the second power source, and the second operation signal controls the switching of the plurality of switches to connect at least one of the plurality of capacitors in parallel with the second power source, wherein the capacitor connected in parallel with the second power source in the first operation is different from the capacitor connected in parallel with the second power source in the second operation.

8. The resonant switching power converter circuit of claim 1, wherein the plurality of capacitors comprises the first capacitor, a second capacitor, a third capacitor coupled to each other;

in the first program, the switches control the first capacitor and the third capacitor to be connected in series between the first power supply and the second power supply, and control the second capacitor to be connected in parallel with the second power supply;

in the second procedure, the switches control the second capacitor and the first capacitor to be connected in series between the second power supply and the grounding potential, and control the third capacitor and the second power supply to be connected in parallel.

9. The resonant switching power conversion circuit of claim 8, wherein the plurality of switches comprises:

a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a seventh switch, an eighth switch, a ninth switch and a tenth switch;

in the first procedure, the first switch, the second switch and the third switch are conducted to control the first capacitor and the third capacitor to be connected in series between the first power supply and the second power supply, the fourth switch and the fifth switch are conducted to control the second capacitor and the second power supply to be connected in parallel, and the sixth switch to the tenth switch are not conducted;

in the second procedure, the sixth switch, the seventh switch and the eighth switch are turned on to control the second capacitor and the first capacitor to be connected in series between the second power supply and the ground potential, and the ninth switch and the tenth switch are turned on to control the third capacitor and the second power supply to be connected in parallel.

10. The resonant switching power converter circuit of claim 9, wherein the plurality of capacitors further includes an output capacitor coupled to the first capacitor, the second capacitor, and the third capacitor, the predetermined voltage includes a first predetermined voltage and a second predetermined voltage, and the control circuit performs at least one of the following operations in the pre-charge mode:

turning on the fourth switch, the fifth switch, the seventh switch, the ninth switch and the tenth switch, and controlling the pre-charge circuit to charge the voltage drop of the output capacitor, the third capacitor and the second capacitor to the first preset voltage;

conducting the second switch and the tenth switch, and controlling the pre-charge circuit to charge the voltage drop of the third capacitor to the first preset voltage;

turning on the fifth switch, the seventh switch and the eighth switch, and controlling the pre-charge circuit to charge the voltage drop of the second capacitor and the first capacitor to the first preset voltage; or

And turning on the eighth switch, and controlling the pre-charge circuit to charge the voltage drop of the first capacitor to the second preset voltage.

11. The resonant switching power converter circuit of claim 10, wherein the first predetermined voltage is a target voltage of a second voltage of the second power source, the second predetermined voltage being twice the target voltage of the second power source.

12. The resonant switching power converter circuit of claim 8, further comprising one of:

(1) The third capacitor is also directly connected in series with the first inductor to form a first resonant tank, and the second capacitor is also directly connected in series with the second inductor to form a second resonant tank;

in the first program, the switches further control the first resonant tank and the first capacitor to be connected in series between the first power supply and the second power supply, and further control the second resonant tank and the second power supply to be connected in parallel;

wherein, in the second procedure, the switches further control the second resonance tank and the first capacitor to be connected in series between the second power supply and the ground potential, and further control the first resonance tank and the second power supply to be connected in parallel;

(2) The first inductor and the second inductor are a single same inductor, and the inductor is coupled between the second power supply and a switching node;

in the first program, the switches further control the first capacitor and the third capacitor to be connected in series between the first power supply and the second power supply after being connected in series with the inductor through the switching node, and control the second capacitor to be connected in parallel with the second power supply after being connected in series with the inductor through the switching node;

in the second program, the switches further control the second capacitor and the first capacitor to be connected in series between the second power supply and the ground potential after being connected in series with the inductor through the switching node, and control the third capacitor to be connected in parallel with the second power supply after being connected in series with the inductor through the switching node; or

(3) The first inductor is coupled between the second power supply and a first switching node, and the second inductor is coupled between the second power supply and a second switching node;

in the first program, the switches further control the first capacitor and the third capacitor, and are connected in series between the first power supply and the second power supply after being connected in series with the first inductor through the first switching node, and are also controlled in parallel with the second power supply after being connected in series with the second inductor through the second switching node;

in the second procedure, the switches also control the second capacitor and the first capacitor to be connected in series between the second power supply and the ground potential after being connected in series with the second inductor through the second switching node, and also control the third capacitor to be connected in parallel with the second power supply after being connected in series with the first inductor through the first switching node.

13. The resonant switching power conversion circuit of claim 1 or 12, wherein the at least one switching converter comprises a first switching converter and a second switching converter, wherein the first switching converter and the second switching converter are coupled in parallel with each other between the first power source and the second power source, and wherein the first switching converter and the second switching converter switch the corresponding switches of each switching converter in opposite phases.

14. The resonant switching power converter circuit of claim 12, wherein the resonant switching power converter circuit has characteristic (3) and the first inductor and the second inductor are both operated in continuous conduction mode.

15. The resonant switching power converter circuit of claim 1, further comprising an upper capacitor and a plurality of upper switches, wherein the at least one switching converter comprises a first switching converter and a second switching converter; wherein the upper capacitor, the plurality of upper switches, the first switching converter and the second switching converter are coupled to each other in a basic topology;

in the first program, the upper switches control the first switching converter and the upper capacitor to be connected in series between the first power supply and the second power supply, and control the second switching converter to be connected in parallel with the second power supply;

in the second procedure, the upper switches control the second switching converter and the upper capacitor to be connected in series between the second power supply and the ground potential, and control the first switching converter and the second power supply to be connected in parallel.

16. The resonant switching power converter circuit of claim 15, wherein a ratio of the first voltage of the first power source to the second voltage of the second power source is 8.

17. The resonant switching power converter circuit of claim 15, further comprising a further upper capacitor, a plurality of further upper switches, a further upper first switching converter, and a further upper second switching converter, wherein the further upper capacitor, the plurality of further upper switches, the further upper first switching converter, and the further upper second switching converter are further coupled to each other in a recursive-spread manner corresponding to the basic topology; the first switching converter of the upper layer and the second switching converter of the upper layer correspond to the resonant switching power conversion circuit of the next layer recursively.

18. The resonant switching power converter circuit of claim 1, wherein the at least one first inductor is a plurality of charging inductors respectively connected in series with the plurality of capacitors, and wherein the at least one second inductor is a plurality of discharging inductors, and wherein the plurality of capacitors and the plurality of charging inductors are connected in series between the first power source and the second power source by switching the plurality of switches to form the first current path; in the second procedure, the plurality of charging inductors are used as the plurality of discharging inductors, and the plurality of discharging inductors and the plurality of capacitors are respectively connected in series between the second power supply and the ground potential correspondingly through the switching of the plurality of switches to form the plurality of second current paths, wherein the plurality of second current paths are connected in parallel with each other.

19. The resonant switching power conversion circuit of claim 1, wherein the at least one first inductor and the at least one second inductor have mutual inductance with each other.

20. The resonant switching power conversion circuit of claim 19, wherein the at least one first inductor and the at least one second inductor having mutual inductance with respect to each other are configured as mutual inductors or as a transformer.

21. The resonant switching power converter circuit of claim 1, wherein the at least one first inductor is a single first inductor and the at least one second inductor is a single second inductor.

22. The resonant switching power converter circuit of claim 21, wherein an inductance of the single first inductor is equal to an inductance of the single second inductor.

23. The resonant switching power converter circuit of claim 1, wherein the at least one first inductor and the at least one second inductor are a single same inductor.

24. The resonant switching power converter circuit of claim 1 or 21, wherein the first program has a first resonant frequency and the second program has a second resonant frequency, and the first resonant frequency is the same as the second resonant frequency.

25. The resonant switching power converter circuit of claim 1, 21, 22 or 23, wherein the first program has a first resonant frequency and the second program has a second resonant frequency, and the first resonant frequency is different from the second resonant frequency.

26. The resonant switching power conversion circuit of claim 1, 21, 22, or 23, wherein a voltage conversion ratio of a first voltage of the first power supply to a second voltage of the second power supply of the switching converter is 4:1, 3:1, or 2:1.

27. The resonant switching power converter circuit of claim 8, wherein a voltage conversion ratio of a first voltage of the first power source to a second voltage of the second power source of the switching converter is 4:1.

28. The resonant switching power converter circuit of claim 27, wherein in a steady state, a ratio of a voltage across the first capacitor to the second voltage is 2, a ratio of a voltage across the third capacitor to the second voltage is 1, and a ratio of a voltage across the second capacitor to the second voltage is 1.

29. The resonant switching power converter circuit of claim 8, wherein the first inductor and the second inductor are a single same inductor, and in a 2-fold conversion mode, a portion of the switches are constantly turned on, another portion of the switches are constantly turned off, and another portion of the switches are used to switch a capacitor of the second capacitor or the first capacitor, such that the capacitor and the inductor are connected in series between the first power source and the second power source in the first procedure, and the capacitor and the inductor are connected in series and then connected in parallel to the second power source in the second procedure, such that a ratio of a first voltage of the first power source to a second voltage of the second power source is 2, wherein the inductor and the capacitor operate in a resonant manner to achieve power conversion between the first power source and the second power source.

30. The resonant switching power converter circuit of claim 8, wherein in a 2-fold conversion mode, a portion of the plurality of switches are constantly conducting, another portion of the plurality of switches are constantly non-conducting, and another portion of the plurality of switches are configured to switch the first capacitor such that the first capacitor and the first inductor are connected in series between the first power source and the second power source in the first procedure, and are connected in parallel to the second power source after the first capacitor and the second inductor are connected in series in the second procedure, such that a ratio of a first voltage of the first power source to a second voltage of the second power source is 2, wherein the first inductor and the second inductor operate in a resonant manner with the first capacitor to achieve power conversion between the first power source and the second power source.

31. The resonant switching power conversion circuit of claim 8, wherein the first inductor and the second inductor are a single same inductor, and in a 3-fold switching mode, a part of the switches are constantly turned on, another part of the switches are constantly turned off, and another part of the switches are used to switch the first capacitor and the third capacitor, such that the first capacitor, the third capacitor and the inductor are connected in series between the first power source and the second power source in the first procedure, and the first capacitor and the third capacitor are connected in series with the inductor after being connected in parallel in the second procedure, and then connected in parallel to the second power source, such that a ratio of a first voltage of the first power source to a second voltage of the second power source is 3, wherein the inductor and the first capacitor, and/or the inductor and the third capacitor operate in a resonant manner to achieve power conversion between the first power source and the second power source.

32. The resonant switching power converter circuit of claim 8, wherein in a 3-fold conversion mode, a portion of the switches are constantly conducting, another portion of the switches are constantly non-conducting, and another portion of the switches are used to switch the first capacitor and the third capacitor, such that the first capacitor, the third capacitor and the first inductor are connected in series between the first power source and the second power source in the first procedure, and the first capacitor and the third capacitor are connected in series with the second inductor and the first inductor, respectively, and then connected in parallel with the second power source in the second procedure, such that a ratio of a first voltage of the first power source to a second voltage of the second power source is 3, wherein the second inductor and the first capacitor, and/or the first inductor and the third capacitor operate in a resonant manner to achieve power conversion between the first power source and the second power source.

33. The resonant switching power converter circuit of claim 1, wherein the predetermined voltage has a fixed proportional relationship with the first voltage of the first power source.

34. The resonant switching power converter circuit of claim 8, wherein the first inductor and the second inductor are a single same inductor, and the capacitance of the first capacitor is much larger than the capacitance of the third capacitor and the second capacitor, such that the first resonant frequency of the third capacitor and the inductor and the second resonant frequency of the second capacitor and the inductor are both higher than or equal to 10 times the third resonant frequency of the first capacitor and the inductor.

35. A resonant switching power conversion circuit for converting a first power to a second power or vice versa, the resonant switching power conversion circuit comprising:

at least one resonant tank, which has a resonant capacitor and a resonant inductor connected in series with each other;

a plurality of switches, coupled to the at least one resonant tank, for switching an electrical connection relationship of the corresponding resonant tank according to a corresponding first operation signal and a corresponding second operation signal in a resonant voltage conversion mode to correspond to a first resonant procedure and a second resonant procedure, wherein the corresponding resonant tank is resonantly charged in the first resonant procedure, and wherein the corresponding resonant tank is resonantly discharged in the second resonant procedure;

a control circuit for controlling the plurality of switches;

a pre-charge circuit coupled between the control circuit and the switches except a first switch; and

at least one non-resonant capacitor coupled to the at least one resonant tank, wherein in the resonant voltage conversion mode, the first operating signal and the second operating signal switch the non-resonant capacitor to electrically connect to the at least one resonant tank, and the voltage across the non-resonant capacitor is maintained in a fixed ratio to the first power source;

the control circuit is coupled to the first power supply, the second power supply and the switches, and is configured to control the first switch of the switches to control an electrical connection relationship between the first power supply and the at least one resonant tank and control the other switches to control the pre-charge circuit to charge at least one of the resonant capacitor and the at least one non-resonant capacitor to a predetermined voltage when a voltage drop of the at least one of the resonant capacitor and the at least one non-resonant capacitor is lower than the predetermined voltage when the resonant switching power conversion circuit operates in a pre-charge mode;

wherein, the first switch is electrically connected between the first power supply and the resonant capacitor;

in a starting mode, the first operation signal and the second operation signal are respectively used for correspondingly operating the switches to switch the electrical connection relation between the non-resonant capacitor and the at least one resonant tank, so that the resonant switching power conversion circuit is operated in the starting mode after the pre-charging mode is finished;

in the start-up mode, the first operating signal and the second operating signal are respectively switched to a conducting level for a conducting period, and the conducting periods are not overlapped with each other, wherein the time lengths of the conducting periods are gradually increased;

in the resonant voltage conversion mode, the first operation signal and the second operation signal are respectively switched to the conducting level for a conducting period, and the conducting periods are not overlapped with each other, so that the first resonant procedure and the second resonant procedure are not overlapped with each other, and the resonant switching type power conversion circuit is operated in the resonant voltage conversion mode after the starting mode is finished, and the first resonant procedure and the second resonant procedure are repeatedly and alternately sequenced to convert the first power supply into the second power supply or convert the second power supply into the first power supply.

36. The resonant switching power converter circuit of claim 35, wherein the predetermined voltage is a target voltage of the second power source.

37. The resonant switching power converter circuit of claim 35, wherein the predetermined voltage is a positive integer multiple of a target voltage of the second power source.

38. The resonant switching power converter circuit of claim 35, wherein the precharge circuit comprises:

a current source for generating a pre-charge current; and

and a pre-charge switch circuit coupled between the current source and the plurality of switches except the first switch, wherein in the pre-charge mode, the control circuit controls the pre-charge switch circuit and the plurality of switches except the first switch to control the electrical connection relationship between the current source and the at least one of the resonant capacitor and the at least one non-resonant capacitor, and further charges the voltage drop of the at least one of the resonant capacitor and the at least one non-resonant capacitor to the preset voltage according to the pre-charge current.

39. The resonant switched-mode power converter circuit of claim 35, wherein the control circuit comprises:

a duty ratio decision circuit for comparing a ramp-up voltage of a ramp-up node with a periodic waveform signal to generate a duty ratio signal;

a duty ratio distribution circuit for generating the first operation signal and the second operation signal according to the duty ratio signal; and

the ramp-up voltage of the ramp-up node gradually rises in the start mode, so that the duty ratios of the first operating signal and the at least one second operating signal correspondingly gradually rise.

40. The resonant switching power converter circuit of claim 35, wherein in the precharge mode, the control circuit controls a conduction level of the first switch such that a precharge current flows from the first power source to the at least one of the resonant capacitor and the at least one non-resonant capacitor via the first switch to charge a voltage drop of the at least one of the resonant capacitor and the at least one non-resonant capacitor to the predetermined voltage.

41. The resonant switching power converter circuit of claim 35, wherein the predetermined voltage has a fixed proportional relationship with the first voltage of the first power source.

42. The resonant switching power converter circuit of claim 35, wherein at least one of the resonant capacitors comprises a first resonant capacitor and a second resonant capacitor, the predetermined voltages comprise a first predetermined voltage, a second predetermined voltage and a third predetermined voltage, the plurality of switches comprise a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a seventh switch, an eighth switch, a ninth switch and a tenth switch, and the control circuit performs at least one of the following operations in the pre-charge mode:

turning on the sixth switch and controlling the pre-charge circuit to charge the voltage drop of the first resonant capacitor to the first preset voltage;

conducting the second switch and the eighth switch, and controlling the pre-charge circuit to charge the voltage drop of the non-resonant capacitor to the second preset voltage; or

And the second switch, the third switch and the tenth switch are conducted, and the pre-charging circuit is controlled to charge the voltage drop of the second resonant capacitor to the third preset voltage.

43. The resonant switching power conversion circuit of claim 42, wherein the first predetermined voltage is three times a target voltage of a second voltage of the second power source, the second predetermined voltage is two times the target voltage of the second voltage, and the third predetermined voltage is the target voltage of the second voltage.