CN113098265B - Single-inductor double-output BUCK switching power supply and charge-discharge control method thereof - Google Patents
Single-inductor double-output BUCK switching power supply and charge-discharge control method thereof Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
- H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
- H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
- H02M3/158—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators including plural semiconductor devices as final control devices for a single load
- H02M3/1584—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators including plural semiconductor devices as final control devices for a single load with a plurality of power processing stages connected in parallel
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Abstract
The application relates to a single-inductor double-output BUCK switch power supply and a charge-discharge control method thereof, wherein a power supply control module of the switch power supply controls the conduction duration of a power supply switch tube by detecting a first output voltage value; when the power switch tube is switched on, the inductor stores energy, the first output voltage rises, the second power switch is switched off, and the second output voltage falls; when the second power switch is turned on, the energy starts to be transmitted to the second output loop, and the first output voltage is reduced until the energy on the inductor is completely released. Two way voltage output branch roads are mutually independent and do not interfere with each other, solve the problem that prior art multichannel output power control is complicated, the system is unstable, adjust many output voltage through the initiative control mode, reach that the load adjustment rate is good, the effect that output voltage precision is high.
Description
Technical Field
The application relates to a single-inductor double-output BUCK switch power supply and a charge and discharge control method thereof, and belongs to the technical field of switch power supplies.
Background
A Single-Inductor Multiple-output (SIMO) dc converter is a new type of switching power supply topology. In the converter of the type, all output channels share the same inductor, so that the aims of saving the inductor, reducing the size of the converter and saving the cost are fulfilled.
At present, the charging and discharging schemes of the single-inductor multiple-output dc-dc converter mainly include two types:
the first is a Time Multiplexing (TM) control method, i.e. in one cycle, for each channel, an inductor is charged first, and then the inductor discharges the channel. For an n-channel converter, the number of times the inductor is charged is n, and the number of times it is discharged is also n.
Another is the sequential power-distribution control (OPDC). That is, in one period, the inductor is charged only once, and then the outputs are discharged in sequence. For an n-channel converter, the number of inductor charges is 1 and the number of discharges is n. The method can greatly reduce the switching action times and the switching loss, so the method is widely applied to the single-inductor multi-output DC-DC converter.
However, in the above control method, the TM control method has a large number of switching operations in a cycle, and a large switching loss. In some cases, the charge and discharge cycles of the channels overlap, and the channels affect each other, thereby generating Cross Regulation (CR). In the OPDC control method, since the channels share the same inductor and the conduction duty ratios of the channels are not independent from each other, when the output load current of one channel changes, the average value of the inductor current and the duty ratio of the channel also change correspondingly, and the changed average value of the inductor current and the duty ratio of the channel affect the output voltages of the other channels, thereby generating cross regulation. The cross adjustment not only makes the voltage ripple of other channels large, but also makes the system unstable in severe cases, which affects the normal operation of the system.
Disclosure of Invention
The application provides a single-inductor double-output BUCK switch power supply and a charge and discharge control method thereof, and can solve the problems that in the prior art, a multi-output power supply is complex to control and a system is unstable.
In order to solve the technical problems, the single-inductor dual-output BUCK switch power supply and the charge and discharge control method thereof regulate multiple output voltages in an active control mode, and achieve the effects of good load regulation rate and high output voltage precision.
In order to solve the technical problem, the application provides the following technical scheme:
in a first aspect of the embodiment of the application, a single-inductor dual-output BUCK switch power supply is provided, a power input end (Vin) of the BUCK switch power supply is connected with two parallel first voltage output branches and two parallel second voltage output branches through an energy storage inductor (L1), a power switch tube (Q1) is further connected between the energy storage inductor (L1) and the power input end (Vin), a first power switch is connected in the first voltage output branch in series, and a second power switch is connected in the second voltage output branch in series;
the switching power supply also comprises a power supply control module, wherein the power supply control module is provided with a first voltage feedback end (FB1), a second voltage feedback end (FB2), a first switching signal control end (G1) and a second switching signal control end (G2);
the first switching signal control terminal (G1) is connected with the control terminal of a power switch tube (Q1), and the second switching signal control terminal (G2) is connected with the control terminal of a second power switch (Q2);
the first voltage feedback end (FB1) is connected with a first voltage output end of the first voltage output branch circuit, and is used for controlling the conduction duration of the power switch tube (Q1) by the power control module according to the first output voltage (VOUT1) fed back by the first voltage feedback end (FB 1);
the second voltage feedback end (FB2) is connected with a second voltage output end of the second voltage output branch circuit and used for controlling the on-off of a second power switch (Q2) by the power control module according to a second output voltage (VOUT2) fed back by the second voltage feedback end (FB 2);
and the power supply control module controls the stored energy of the energy storage inductor (L1) to be alternately transmitted to the first voltage output branch and the second voltage output branch in the same power supply switching period by adopting a time division multiplexing control mode according to voltage feedback signals of the first voltage feedback end (FB1) and the second voltage feedback end (FB 2).
A second aspect of an embodiment of the present application provides a charge and discharge control method for a single-inductor dual-output BUCK switching power supply, including:
detecting a first voltage feedback signal of a first voltage output branch circuit and a second voltage feedback signal of a second voltage output branch circuit of a power output end in real time;
controlling the conduction duration of a power switch tube according to the first voltage feedback signal;
controlling the conduction time of a second power switch according to the second voltage feedback signal;
in the current power switch period, when the second power switch is switched on, the first power switch is switched off, the first output voltage starts to be reduced, and the second output voltage starts to be increased;
when the current power switch cycle is finished, the second power switch is switched off, the power switch tube is switched on, the first output voltage starts to rise, and the steps are repeated.
The beneficial effect of this application lies in: the switching power supply is provided with two voltage output branches which are connected in parallel, a time division multiplexing working mode is utilized in the same period, the two voltage output branches are mutually independent and are not interfered, the working efficiency of the power supply is improved, and the application occasions of the power supply are increased.
The second output voltage VOUT2 is lower than the first output voltage VOUT 1.
When the inductor discharges to the first voltage output branch circuit, the minimum conduction time of the diode D2 is limited, and therefore the output stability of VOUT1 is guaranteed.
This application is through detecting two way output voltage, and the break-make of actively adjusting second power switch Q2 and power switch tube Q1 switch on for a long time, can obtain accurate VOUT1 and VOUT2 output.
The foregoing description is only an overview of the technical solutions of the present application, and in order to make the technical solutions of the present application more clear and clear, and to implement the technical solutions according to the content of the description, the following detailed description is made with reference to the preferred embodiments of the present application and the accompanying drawings.
Drawings
Fig. 1 is a block diagram of a single-inductor dual-output BUCK switching power supply according to an embodiment of the present disclosure
FIG. 2 is a schematic circuit diagram of a single-inductor dual-output BUCK switching power supply according to an embodiment of the present application;
FIG. 3 is a schematic diagram of an internal circuit of a main control chip core2 according to an embodiment of the present application;
fig. 4 is an operation timing diagram of a dual output BUCK switching power supply according to an embodiment of the present application.
Detailed Description
The following detailed description of embodiments of the present application will be described in conjunction with the accompanying drawings and examples. The following examples are intended to illustrate the present application but are not intended to limit the scope of the present application.
A switching power supply, namely a switching stabilized voltage supply, is a novel stabilized voltage supply circuit relative to a linear stabilized voltage supply, and stabilizes output voltage by monitoring the output voltage in real time and dynamically controlling the on-off time ratio of a switching tube in a switching power supply circuit.
Fig. 1 is a block diagram of a circuit structure of a single-inductor dual-output BUCK switching power supply according to an embodiment of the present invention, where only one output is connected in parallel to an output terminal of a typical BUCK switching power supply, and only one inductor is needed, two voltage outputs, i.e., VOUT1 and VOUT2, can be independently controlled.
As shown in fig. 1, an input terminal of the BUCK switch power supply is connected to a first voltage output branch and a second voltage output branch through a power switch Q1 and a BUCK converter, the first voltage output branch is connected in series with a first power switch, and the first voltage output branch outputs a first output voltage VOUT 1; the second voltage output branch is connected with a second power switch in series and outputs a second output voltage VOUT 2. And VOUT1 is greater than VOUT 2.
A dashed line frame in fig. 1 is a power supply control module of the dual-output BUCK switching power supply, and G1 is a first switching signal control end of the power supply control module, connected to a control end of a power switching tube Q1, and configured to output a control signal of the power switching tube Q1; g2 is a second switch signal control terminal of the power control module, connected to the control terminal of the second power switch Q2, and configured to output a control signal of the second power switch Q2.
The FB1 is a first voltage feedback terminal of the power control module, the FB2 is a second voltage feedback terminal of the power control module, and the power control module receives a voltage feedback signal of VOUT1 through the first voltage feedback terminal FB1 and receives a voltage feedback signal of VOUT2 through the second voltage feedback terminal FB 2.
The power control module outputs a PWM switching signal to the power switch tube Q1 through G1 according to the received two-path voltage feedback signal, and controls the on-off of the power switch tube Q1. The second power switch Q2 is turned on and off by outputting a PWM switching signal to the second power switch Q2 through G2.
The power control module controls a first voltage output branch of the output VOUT1 and a second voltage output branch of the output VOUT2 to be conducted alternately. The time division multiplexing working mode is utilized in the same power switch period, the two paths of voltage output are mutually independent and are not interfered, and the working efficiency of the power supply is improved.
In this embodiment, when the power control module detects that the output voltage VOUT1 is low through the first voltage feedback terminal FB1, the first switching signal control terminal G1 outputs the PWM switching signal to control the on-time of the switching transistor Q1 to be increased, i.e., to increase the duty ratio.
When the power control module detects that the output voltage VOUT1 is higher through the first voltage feedback terminal FB1, the PWM switching signal is output through the first switching signal control terminal G1 to control to decrease the on-time of the power switch Q1, i.e., decrease the duty ratio.
Under the condition that the first voltage output branch is conducted, the power supply control module outputs a control signal to control the switch tube Q2 to be conducted if the voltage VOUT2 is detected to be smaller than a preset value according to a voltage feedback signal of VOUT2 received by FB 2; if the voltage VOUT2 is not detected to be smaller than the predetermined value in a power switching cycle, the switch Q2 is always turned off in the power switching cycle.
Further, the power control module of this embodiment includes a driving module core1 and a main control chip core2, wherein the main control chip core2 outputs a switch adjustment signal for controlling the on/off time of the power switch Q1 and the second power switch Q2 by detecting the first output voltage VOUT1 and the second output voltage VOUT 2. The driving module core1 drives the power switch tube Q1 to be switched on and off by receiving the differential signal;
the power control module of the embodiment can actively adjust the on-time duty ratio of the power switching tubes Q1 and Q2 according to the magnitude of the two output voltages VOUT1 and VOUT2, and finally obtain accurate VOUT1 and VOUT2 outputs.
Fig. 2 is a schematic circuit diagram of a single-inductor dual-output BUCK switching power supply according to an embodiment of the present application, and the structure and operation principle of the BUCK converter are well known to those skilled in the art and will not be described herein again.
As shown in fig. 2, the power input terminal Vin is connected to one end of the energy storage inductor L1 through the power switch Q1, and the other end of the energy storage inductor L1 is connected to the two voltage output branches. Wherein,
optionally, the first voltage output branch includes a first power switch and a capacitor C1 connected in series, where the first power switch is a diode D2, an anode of the diode D2 is connected to the energy storage inductor L1, a cathode of the diode D2, and a series point of a series capacitor C1, a diode D2, and a capacitor C1 is a voltage output terminal VOUT 1. The capacitor C1 is used for voltage stabilization and energy storage, and the diode D2 is used for on-off control of the first voltage output branch.
The high potential end of the power switch tube Q1 is connected with a power input end Vin, the low potential end of the power switch tube Q1 is connected with an energy storage inductor L1, and the drive module core1 is connected with the control end of the power switch tube Q1 through a port G1 and is used for driving the Q1 to be switched on and off according to differential signals received by differential signal receiving ends D3 and D4.
Optionally, the second voltage output branch comprises a second power switch Q2 and a capacitor C4 connected in series, wherein the second power switch Q2 is a switching tube. The high potential end of the second power switch Q2 is connected to the energy storage inductor L1, the low potential end of the second power switch Q2 is grounded through a capacitor C4, the series point of the second power switch Q2 and the capacitor C4 is a VOUT2 voltage output end, and the control end G2 of the main control chip core2, i.e., the second switch signal control end G2 of the power control module, is connected to the control end of the second power switch Q2. The capacitor C4 is used for voltage stabilization and energy storage, and the second power switch Q2 is used for on-off control of the second voltage output branch.
Optionally, the first voltage feedback terminal FB1 of the main control chip core2 of the present embodiment is connected to the voltage output terminal VOUT1, i.e., to the cathode of the diode D2, for receiving the voltage feedback signal of VOUT1 through FB 1. The second voltage feedback terminal FB2 of the main control chip core2 is connected to the voltage output terminal VOUT2, i.e., to the low potential terminal of the second power switch Q2, for receiving the voltage feedback signal VOUT2 through FB 2.
Optionally, the present embodiment is provided with a differential signal output circuit, and the differential signal receiving terminals D3 and D4 of the driving module core1 are connected to the differential signal output terminals of the differential signal output circuit. The differential signal control terminals G3 and G4 of the master control chip core2 are connected to the control terminals of the differential signal output circuit.
The main control chip core2 is used for controlling the differential signal output circuit to output different differential signals according to a voltage feedback signal of VOUT1, and the driving module controls the on-off of the power switch tube Q1 according to the differential signals.
Specifically, the differential signal output circuit includes a first switch Q3 and a second switch Q4, a high-potential end of the first switch Q3 is connected to the differential signal receiving end D3 of the drive module core1, and a low-potential end of the first switch Q3 is grounded.
The high-potential end of the second switch tube Q4 is connected with the differential signal receiving end D4 of the drive module core1, and the low-potential end of the second switch tube Q4 is grounded; the differential signal control terminal G3 of the master control chip core2 is connected with the control terminal of Q3, and the differential signal control terminal G4 of the master control chip core2 is connected with the control terminal of Q4.
The main control chip core2 outputs control signals to the control ends of the Q3 and the Q4 according to the detected VOUT1 voltage, and the driving module core1 drives and controls the on-off of the switch tube Q1 according to differential signals generated by the switch tubes Q3 and Q4. The method specifically comprises the following steps:
when the differential signal control terminal G3 outputs a high level signal to Q3 and G4 outputs a low level signal to Q4, Q3 is driven to be turned on and Q4 is driven to be turned off respectively. At this time, the differential signal receiving terminal D3 of the driving module core1 receives a low level signal, and the differential signal receiving terminal D4 receives a high level signal. The driving module core1 drives the power switch Q1 to conduct according to the differential signal generated by Q3 and Q4.
When the differential signal control terminal G3 outputs a low level signal, G4 outputs a high level signal, which drives Q3 to turn off and Q4 to turn on, respectively. At this time, the D3 terminal of the driving module core1 receives a high signal, and the D4 terminal receives a low signal. The driving module core1 actively adjusts the Q1 of the switch tube to be cut off according to the differential signals generated by the Q3 and the Q4.
In the embodiment, since the driving module core1 is not grounded with the main control chip core2, the differential signals generated by the Q3 and the Q4 are used for communication, and the circuit design is more convenient.
Optionally, the power control module further includes a first energy storage circuit for supplying power to the drive module core1 and a second energy storage circuit for supplying power to the main control chip core 2.
The first energy storage circuit comprises a diode D3 and a capacitor C2. The second tank circuit includes a capacitor C3.
Specifically, the anode of the diode D3 is connected to the VOUT1 voltage output terminal, and the cathode of the diode D3 is connected to the VCC1 of the core1 of the driving module. The output voltage VOUT1 supplies the driver module Core1 via a diode D3. The capacitor C2 is used for voltage stabilization and energy storage.
The positive pole of the capacitor C3 is connected with the power supply terminal VCC2 of the main control chip core2, the negative pole of the capacitor C3 is grounded, and the capacitor C3 is used for voltage stabilization and energy storage.
When the switching power supply is started stably, the capacitor C2 and the capacitor C3 respectively supply power to the drive module core1 and the main control chip core2, and normal work of the circuit module is guaranteed.
Alternatively, the switching tubes Q1, Q2, Q3 and Q4 may be MOS tubes. Or a triode. In actual operation, a MOS transistor or a triode may be selected according to needs, and this embodiment is not limited herein.
Fig. 3 is a schematic diagram of an internal circuit of the main control chip core2 in this embodiment, and optionally, the main control chip core2 in this embodiment of the present application includes a first differential amplifier AMP1, a second differential amplifier AMP2, a first comparator CMP1, a second comparator CMP2, and a differential signal modulation circuit CTRL. Wherein,
the non-inverting input terminal of the first differential amplifier AMP1 is coupled to the reference voltage VREF1, and the inverting input terminal of the first differential amplifier AMP1 is coupled to the first voltage feedback signal FB 1. The non-inverting input terminal of the second differential amplifier AMP2 is coupled to the second voltage feedback signal FB2, and the inverting input terminal of the second differential amplifier AMP2 is coupled to the reference voltage VREF 2.
The first differential amplifier AMP1 and the second differential amplifier AMP2 are used for differentially amplifying the input signal, and when the first voltage feedback signal FB1 is less than the reference voltage VREF1, the output signal out1 increases with the decrease of the FB 1; when the second voltage feedback signal FB2 is greater than the reference voltage VREF2, the output signal out2 decreases as FB2 decreases.
The ramp signal VRAMP is input to the inverting input terminal of the first comparator CMP1 and the non-inverting input terminal of the second comparator CMP2, the non-inverting input terminal of the first comparator CMP1 is connected to the output signal out1 at the output terminal of the first differential amplifier AMP1, and the inverting input terminal of the second comparator is connected to the output signal out2 of the second differential amplifier AMP 2. The output end of the first comparator is connected to the differential signal modulation circuit CTRL, and the output end of the second comparator is a second switching signal control end G2.
When the voltage value of the ramp signal VRAMP is higher than out2, the second comparator CMP2 outputs a high level signal to the control terminal of G2, and controls the second power switch Q2 to be turned on until the current power switch cycle is over and the second power switch Q2 is turned off.
The differential signal modulation circuit CTRL is configured to modulate the received output signal of the first comparator CMP1 into a differential control signal, and output the differential control signal through the ports G3 and G4.
When a new switching cycle arrives, the differential signal modulation circuit CTRL generates a differential signal that turns on the power switch Q1, and the power switch Q1 turns on first.
With the rising of the ramp signal VRAMP, when the voltage value of the ramp signal VRAMP is higher than out1, the first comparator CMP1 outputs a low level signal to the differential signal modulation circuit CTRL, so that the differential signal modulation circuit CTRL generates a differential signal for turning off the power switch Q1.
In this embodiment, the second comparator CMP2 has a minimum limit on the inverting input voltage, which ensures a minimum on-time t for the diode D2min。
The drive module core1 of the embodiment of the present application adopts the prior art, and the drive module of the switching tube belongs to the technology well known in the art, and is not described herein again.
The specific working process of the embodiment of the application is as follows: after the switching power supply is started, the main control chip core2 and the driving module core1 start to work normally, when the Q1 is conducted, the energy storage inductor L1 starts to store electricity, after the diode D2 is conducted, the voltage of VOUT1 starts to rise, at the moment, the second power switch Q2 is in a cut-off state, and energy cannot be transmitted to the VOUT 2.
With the continuous rising of the output voltage VOUT1, in the process, after the on-time of the diode D2 reaches the minimum on-time, if the main control chip core2 detects that the output voltage VOUT2 is smaller than the preset value through the second voltage feedback terminal FB2, the second switch signal control terminal G2 outputs a high level signal to drive the second power switch Q2 to be turned on.
At this time, the anode voltage of the diode D2 is pulled low, the diode D2 is turned off, the energy on the power supply only supplies power to the load of VOUT2, and the output voltage VOUT2 begins to rise. At this time, the load voltage VOUT1 is maintained by discharging only capacitor C1, so VOUT1 begins to drop.
When the main control chip core2 detects that VOUT1 is lower than the preset value through the first voltage feedback terminal FB1 and the load is heavy, a switch control signal with a high on-duty ratio is modulated, and in the next power switching period, the on-time of the power switching tube Q1 is controlled and increased through the output differential signal. When the next power switch cycle arrives, the main control chip core2 outputs a low level signal through the second switch signal control terminal G2, and controls the second power switch Q2 to be turned off; meanwhile, the main control chip core2 generates a differential signal to the driving module core1, so as to drive the power switch Q1 to be turned on.
When the main control chip core2 detects that VOUT1 is lower than the preset value through the first voltage feedback terminal FB1 and the load is light, a switch control signal with a low on-duty ratio is modulated, and the on-time of the power switch tube is reduced through differential signal control in the next power switch period.
In this process, when the main control chip core2 detects that the output voltage VOUT2 is smaller than the preset value according to the second voltage feedback terminal FB2, the second power switch Q2 is driven to turn on again until the next power switch cycle arrives or the energy on the energy storage inductor L1 is exhausted, and the second power switch Q2 is controlled to turn off.
In this embodiment, under the condition that the switching tube Q1 is turned on, it is required to ensure that the turn-on duration of the diode D2 reaches the minimum turn-on duration, and then it is started to detect whether VOUT2 is smaller than the preset value, and when detecting that VOUT2 voltage is smaller than the preset value, the switching tube Q2 is controlled to be turned on, so that the output stability of VOUT1 is ensured.
Fig. 4 is a timing diagram illustrating the operation of the dual-output BUCK switching power supply according to an embodiment of the present invention, as shown in fig. 4, G1 represents the control signal of the power switch Q1, G2 represents the control signal of the second power switch Q2, I1 and I2 represent the currents flowing through the first voltage output branch and the second voltage output branch, and VOUT1 and VOUT2 represent the first output voltage and the second output voltage.
Referring to fig. 4, when the power supply enters a new switching cycle, the power switching transistor Q1 is turned on first, and its on duty cycle is determined by VOUT1 detected in the previous cycle.
When the power switch tube Q1 is turned on, that is, when G1 is at a high level, the energy storage inductor L1 is charged, the current I1 rises, the diode D2 is turned on, the capacitor C1 is charged, and VOUT1 rises; when the power switch Q1 is turned off, i.e., G1 goes low, the energy storage inductor L1 discharges, the current I1 continues to rise, the capacitor C1 charges, and VOUT1 continues to rise.
When D2 reaches the minimum on-time tminThen, if the VOUT2 is detected not to be smaller than the preset value, the current I1 continues to rise, and the VOUT1 rises; if VOUT2 is detected to be smaller than the preset value, G2 is controlled to be turned to high level, so that the second power switch Q2 is conducted.
With the second power switch Q2 turned on, if the power switch Q1 is still in the on state, the current in the energy storage inductor L1 continues to rise, the current I2 rises, the capacitor C4 charges, and VOUT2 rises. At this time, VOUT1 is maintained only by capacitor C1, and therefore VOUT1 drops. When the power switch Q1 is turned off, the energy storage inductor L1 discharges, the current I2 drops, the capacitor C4 continues to be charged, VOUT2 continues to rise, and VOUT1 is maintained only by the capacitor C1 at this time, so VOUT1 drops.
Until the end of the current power switch cycle, the second power switch Q2 turns off, at which time VOUT2 is maintained only by capacitor C4, and therefore VOUT2 drops.
To sum up, the power control circuit of the embodiment of the application, through the active control mode, when detecting that the voltage is reduced, through actively adjusting the on-off of the switch tube Q2 and the on-off duration of the switch tube Q1, finally obtaining accurate VOUT1 and VOUT2 outputs, in the same power switch period, utilizing the time division multiplexing working mode, the dual-output power is mutually independent and not interfered, thereby improving the working efficiency of the power supply and increasing the application occasions of the power supply.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (9)
1. The utility model provides a single inductance dual output BUCK switching power supply which characterized in that:
the power supply input end (Vin) of the BUCK switch power supply is connected with two parallel-connected first voltage output branch circuits and second voltage output branch circuits through an energy storage inductor (L1), a power supply switch tube (Q1) is connected between the energy storage inductor (L1) and the power supply input end (Vin), a first power supply switch is connected in series in the first voltage output branch circuits, and a second power supply switch is connected in series in the second voltage output branch circuits;
the switching power supply also comprises a power supply control module, wherein the power supply control module is provided with a first voltage feedback end (FB1), a second voltage feedback end (FB2), a first switching signal control end (G1) and a second switching signal control end (G2);
the first switching signal control terminal (G1) is connected with the control terminal of a power switch tube (Q1), and the second switching signal control terminal (G2) is connected with the control terminal of a second power switch (Q2);
the first voltage feedback end (FB1) is connected with a first voltage output end of the first voltage output branch circuit, and is used for controlling the conduction duration of the power switch tube (Q1) by the power control module according to the first output voltage (VOUT1) fed back by the first voltage feedback end (FB 1);
the second voltage feedback end (FB2) is connected with a second voltage output end of the second voltage output branch circuit and used for controlling the on-off of a second power switch (Q2) by the power control module according to a second output voltage (VOUT2) fed back by the second voltage feedback end (FB 2);
the power supply control module controls the stored energy of the energy storage inductor (L1) to be alternately transmitted to the first voltage output branch and the second voltage output branch in the same power supply switching period by adopting a time division multiplexing control mode according to voltage feedback signals of the first voltage feedback end (FB1) and the second voltage feedback end (FB 2);
the power control module comprises a main control chip (Core2), a driving module and a differential signal output circuit, the second switch signal control end (G2), the first voltage feedback end (FB1) and the second voltage feedback end (FB2) are arranged on the main control chip (Core2), and the first switch signal control end (G1) is arranged on the driving module;
the differential signal control end (G3, G4) of master control chip (Core2) are connected differential signal output circuit's control end for control differential signal output circuit outputs different differential signal, the differential signal that differential signal output circuit output is connected to drive module's differential signal receiving terminal (D3, D4), drive module basis differential signal output control power switch tube (Q1) switch-on duration's on-off adjustment signal.
2. The BUCK switching power supply as claimed in claim 1, wherein the main control chip (Core2) comprises a first differential amplifier AMP1, a second differential amplifier AMP2, a first comparator CMP1, a second comparator CMP2, and a differential signal modulation circuit CTRL;
the non-inverting input end of the first differential amplifier AMP1 is connected to a reference voltage VREF1, and the inverting input end of the first differential amplifier AMP1 is a first voltage feedback end (FB 1); the non-inverting input end of the second differential amplifier AMP2 is a second voltage feedback end (FB2), and the inverting input end of the second differential amplifier AMP2 is connected to the reference voltage VREF 2;
the non-inverting input end of the first comparator CMP1 is connected with the output end of the first differential amplifier AMP1, and the inverting input end of the first comparator CMP1 is connected with a ramp signal; the output end of the second differential amplifier AMP2 is connected with the inverting input end of a second comparator CMP2, the non-inverting input end of the second comparator CMP2 is connected with a ramp signal, and the output end of the second comparator is a second switching signal control end (G2);
the input end of the differential signal modulation circuit is connected with the output end of the first comparator CMP1, and the output end of the differential signal modulation circuit is the differential signal control end (G3, G4).
3. The BUCK switch power supply of claim 1, wherein the differential signal output circuit comprises a first switch tube (Q3) and a second switch tube (Q4), the high-potential ends of the first switch tube (Q3) and the second switch tube (Q4) are connected with the differential signal receiving ends (D3 and D4) of the driving module, the low-potential ends of the first switch tube (Q3) and the second switch tube (Q4) are grounded, and the differential signal control ends (G3 and G4) of the main control chip (Core2) are correspondingly connected with the control ends of the first switch tube (Q3) and the second switch tube (Q4).
4. The BUCK switch power supply of claim 1, wherein the first voltage output branch comprises a first power switch and a capacitor (C1) connected in series, the first power switch being a diode (D2); the anode of the diode (D2) is connected with the energy storage inductor (L1), the cathode of the diode (D2) is connected with the anode of the capacitor (C1), the cathode of the capacitor (C1) is grounded, and the connection point of the diode (D2) and the capacitor (C1) is a first voltage output end.
5. The BUCK switch power supply according to claim 1, wherein the second voltage output branch comprises a second power switch (Q2) and a capacitor (C4) connected in series, the high potential terminal of the second power switch (Q2) is connected to the energy storage inductor (L1), the low potential terminal of the second power switch (Q2) is connected to ground through a capacitor (C4), and the series connection point of the second power switch (Q2) and the capacitor (C4) is the second voltage output terminal.
6. The BUCK switch power supply according to any of the claims 1 to 5, wherein the power switch transistor (Q1) and the second power switch (Q2) are MOS transistors or triodes.
7. The BUCK switching power supply of claim 1, wherein the second output voltage (VOUT2) of the second voltage output branch is lower than the first output voltage (VOUT1) of the first voltage output branch.
8. The charge-discharge control method of the single-inductor dual-output BUCK switch power supply as claimed in claim 1, comprising:
detecting a first voltage feedback signal of a first voltage output branch circuit and a second voltage feedback signal of a second voltage output branch circuit of a power output end in real time;
controlling the conduction duration of a power switch tube according to the first voltage feedback signal;
controlling the conduction time of a second power switch according to the second voltage feedback signal;
during the current power switch cycle, when the second power switch is turned on, the first power switch is turned off, the first output voltage (VOUT1) starts to decrease, and the second output voltage (VOUT2) starts to increase;
at the end of the current power switch cycle, the second power switch is turned off, the power switch tube is turned on, and the first output voltage (VOUT1) begins to rise, and so on.
9. The BUCK switch power supply of claim 8, wherein the first power switch has a minimum on-time during each power switch cycle.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102332824A (en) * | 2011-09-23 | 2012-01-25 | 东南大学 | Time sharing multiplex control method for single-inductance double-output switching power supply and circuit thereof |
| CN103701307A (en) * | 2013-12-31 | 2014-04-02 | 成都芯源***有限公司 | Single-inductor multi-output buck converter and control circuit and control method thereof |
| CN106374745A (en) * | 2016-09-21 | 2017-02-01 | 西安电子科技大学 | Single-inductor dual-path output DC-DC boosting converter based on voltage intermodulation suppression |
| CN110635702A (en) * | 2019-11-08 | 2019-12-31 | 苏州力生美半导体有限公司 | High-precision multi-output flyback switching power supply circuit and method |
| EP3627681A1 (en) * | 2018-09-19 | 2020-03-25 | Diehl AKO Stiftung & Co. KG | Single inductor multiple output (simo) switch mode power converter |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090040794A1 (en) * | 2007-08-08 | 2009-02-12 | Advanced Analogic Technologies, Inc. | Time-Multiplexed Multi-Output DC/DC Converters and Voltage Regulators |
| US20110187189A1 (en) * | 2010-02-02 | 2011-08-04 | Intersil Americas Inc. | System and method for controlling single inductor dual output dc/dc converters |
-
2021
- 2021-04-13 CN CN202110393731.7A patent/CN113098265B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102332824A (en) * | 2011-09-23 | 2012-01-25 | 东南大学 | Time sharing multiplex control method for single-inductance double-output switching power supply and circuit thereof |
| CN103701307A (en) * | 2013-12-31 | 2014-04-02 | 成都芯源***有限公司 | Single-inductor multi-output buck converter and control circuit and control method thereof |
| CN106374745A (en) * | 2016-09-21 | 2017-02-01 | 西安电子科技大学 | Single-inductor dual-path output DC-DC boosting converter based on voltage intermodulation suppression |
| EP3627681A1 (en) * | 2018-09-19 | 2020-03-25 | Diehl AKO Stiftung & Co. KG | Single inductor multiple output (simo) switch mode power converter |
| CN110635702A (en) * | 2019-11-08 | 2019-12-31 | 苏州力生美半导体有限公司 | High-precision multi-output flyback switching power supply circuit and method |
Non-Patent Citations (2)
| Title |
|---|
| Modeling and Design of Feedback Loops for a Voltage-Mode Single-Inductor Dual-Output Buck Converter;Kun-Yu Lin et al.;《2008 IEEE Power Electronics Specialists Conference》;20080808;第3389页，图1 * |
| 用于单电感双输出Buck变换器的PCPV控制方案;徐利梅等;《西南交通大学学报》;20210228;第56卷(第1期);第182-189页 * |
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