CN115882727A - Step-down converter and power chip - Google Patents
Step-down converter and power chip Download PDFInfo
- Publication number
- CN115882727A CN115882727A CN202310097450.6A CN202310097450A CN115882727A CN 115882727 A CN115882727 A CN 115882727A CN 202310097450 A CN202310097450 A CN 202310097450A CN 115882727 A CN115882727 A CN 115882727A
- Authority
- CN
- China
- Prior art keywords
- module
- switch
- voltage
- level
- buck converter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000003990 capacitor Substances 0.000 claims abstract description 125
- 238000000034 method Methods 0.000 claims abstract description 72
- 230000003321 amplification Effects 0.000 claims description 20
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 20
- 238000001514 detection method Methods 0.000 claims description 16
- 238000004146 energy storage Methods 0.000 claims description 16
- 230000008569 process Effects 0.000 abstract description 63
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 238000006243 chemical reaction Methods 0.000 description 19
- 230000001276 controlling effect Effects 0.000 description 12
- 238000010586 diagram Methods 0.000 description 10
- 230000001105 regulatory effect Effects 0.000 description 6
- 230000009471 action Effects 0.000 description 5
- 230000009467 reduction Effects 0.000 description 4
- 238000005265 energy consumption Methods 0.000 description 3
- 230000009977 dual effect Effects 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 239000013078 crystal Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000036632 reaction speed Effects 0.000 description 1
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
Landscapes
- Dc-Dc Converters (AREA)
Abstract
The invention discloses a buck converter, which relates to the field of power supplies and is applied to a power supply chip.A charging module starts to charge a bootstrap capacitor when the cross voltage at two ends of the bootstrap capacitor is too low, and simultaneously outputs a first level in the charging process, a control module controls a first switch and a second switch to be switched off after receiving the first level, so as to prevent the first switch and the second switch from being started by mistake. The invention also discloses a power supply chip which has the same beneficial effects as the buck converter.
Description
Technical Field
The invention relates to the field of power supplies, in particular to a buck converter. The invention also relates to a power supply chip.
Background
With the widespread use of electronic products powered by batteries, the technology of power supply chips has also been rapidly developed, and the use of power supply chips is the key to prolonging the service life and service life of batteries. Particularly, when applied to a large range of loads, high conversion efficiency, low output ripple voltage and small size are indispensable specifications of the power chip. The inside of the power supply chip mainly comprises a direct current-to-direct current buck converter, and in order to reduce the size of the power supply chip and improve the conversion efficiency, the framework of the double-N-channel switch is widely applied to the power supply chip, and in order to ensure the normal opening and closing of the upper bridge switch in the double-N-channel, a bootstrap circuit is required to be added. However, when the load of the power supply chip is light load, the power supply chip enters a sleep mode of discontinuous conduction to reduce power consumption, if the cross voltage at the two ends of the bootstrap capacitor is too low, the situation that the upper bridge switch in the double N channels cannot be normally started exists, and a solution needs to be provided for charging the bootstrap capacitor, so that the upper bridge switch can be normally started.
In the prior art, when the cross voltage across the bootstrap capacitor is too low, the lower bridge switch in the dual N channels is usually forced to be turned on first to charge the bootstrap capacitor. Generally, a first end of a bootstrap capacitor is connected with a regulated power supply through a diode, a second end of the bootstrap capacitor is respectively connected with a lower bridge switch and an output end of a buck converter, after the lower bridge switch is forcibly turned on, the bootstrap capacitor forms a charging loop through the diode and the lower bridge switch, and current flows to the ground from the bootstrap capacitor through the lower bridge switch through the diode.
Disclosure of Invention
The invention aims to provide a buck converter and a power chip, when the power chip works under light load and is in a discontinuous conduction sleep mode and under the condition of insufficient cross voltage at two ends of a bootstrap capacitor, a path is additionally provided for charging the bootstrap capacitor without forcibly turning on a lower bridge switch, so that the additional energy consumption caused by the conduction of the lower bridge switch is reduced, the power consumption of the power chip can be greatly reduced, the problems of ripple voltage increase output by the buck converter, reduction of the conversion efficiency of the power chip and the like are solved, and the conversion efficiency of the power chip is improved.
In order to solve the above technical problem, the present invention provides a buck converter, which is applied to a power chip, and includes a bootstrap capacitor, a charging module, a control module, a first switch and a second switch;
a first end of the bootstrap capacitor is connected to a first input end of the charging module and a first output end of the charging module respectively, a second end of the bootstrap capacitor is connected to an output end of the buck converter, a second input end of the charging module, and a first end of the first switch is connected to a first end of the second switch respectively;
the second output end of the charging module is connected with the first end of the control module, and the third input end of the charging module is connected with a power supply, and the charging module is used for starting and outputting a first level when the voltage at the two ends of the bootstrap capacitor is smaller than a preset voltage, so that the power supply can charge the bootstrap capacitor; when the voltage at two ends of the bootstrap capacitor is greater than a preset voltage, the bootstrap capacitor is disconnected and outputs a second level, and the first level and the second level are opposite;
the second end of the control module is connected with the output end of the buck converter, the third end of the control module is connected with the second end of the first switch, the fourth end of the control module is connected with the control end of the first switch, and the fifth end of the control module is connected with the control end of the second switch, and is used for controlling the first switch and the second switch to be turned off when the output signal of the charging module is at a first level; when the output signal of the charging module is at a second level, controlling the first switch and the second switch to be switched on and off based on a preset pulse signal and a voltage corresponding to a current flowing through the first switch, so that the buck converter enters a corresponding working state, wherein the working state comprises an energy storage state and an energy release state;
the second end of the first switch is connected with a power supply, and the second end of the second switch is grounded.
Preferably, the charging module includes:
a first input end of the judgment module is connected with a first end of the bootstrap capacitor, a second input end of the judgment module is connected with a second end of the bootstrap capacitor, and an output end of the judgment module is respectively connected with a first input end of the starting module and a first end of the control module and is used for outputting a first level when the voltage at two ends of the bootstrap capacitor is smaller than a preset voltage; outputting a second level when the voltage at two ends of the bootstrap capacitor is greater than a preset voltage, wherein the first level is opposite to the second level;
the second input end of the starting module is connected with a power supply, the output end of the starting module is connected with the first end of the bootstrap capacitor, and the starting module is used for starting when the output signal of the judging module is a first level so that the power supply can charge the bootstrap capacitor; and when the output signal of the judging module is the second level, the circuit is disconnected.
Preferably, the starting module comprises:
a starting switch, wherein a first end of the starting switch is connected with a power supply, and a second end of the starting switch is connected with a first end of the bootstrap capacitor;
the input end of the level voltage converter is connected with the output end of the judging module, the output end of the level voltage converter is connected with the control end of the starting switch, and the level voltage converter is used for controlling the starting switch to be conducted when the output signal of the judging module is a first level so as to enable the power supply to charge the bootstrap capacitor; and when the output signal of the judging module is a second level, the starting switch is controlled to be turned off.
Preferably, the start switch includes:
the first end of the first starting switch is connected with a power supply;
and a first end of the second starting switch is connected with a second end of the first starting switch, and a second end of the second starting switch is connected with a first end of the bootstrap capacitor.
Preferably, the first and second electrodes are formed of a metal,
the preset voltage includes: the voltage control circuit comprises a first preset voltage and a second preset voltage, wherein the second preset voltage is greater than the first preset voltage;
correspondingly, the voltage at the two ends of the bootstrap capacitor is smaller than a preset voltage, and the method includes:
the voltage at two ends of the bootstrap capacitor is smaller than a first preset voltage;
the voltage at the two ends of the bootstrap capacitor is greater than a preset voltage, and the bootstrap capacitor comprises:
and the voltage at two ends of the bootstrap capacitor is greater than a second preset voltage.
Preferably, the control module comprises:
the first input end of the first driving module is connected with a voltage-stabilized power supply, and the output end of the first driving module is respectively connected with the control end and the first end of the first switch;
the first input end of the second driving module is connected with the voltage-stabilized power supply, and the output end of the second driving module is respectively connected with the control end and the first end of the second switch;
the control sub-module is connected with the second output end of the charging module, the second end of the control sub-module is connected with the output end of the buck converter, the third end of the control sub-module is connected with the second end of the first switch, the fourth end of the control sub-module is connected with the second input end of the first driving module, and the fifth end of the control sub-module is connected with the second input end of the second driving module, and is used for controlling the first switch to be turned off based on the first driving module and controlling the second switch to be turned off based on the second driving module when the output signal of the charging module is at the first level; when the output signal of the charging module is at a second level, the first switch and the second switch are controlled to be switched on and off based on a preset pulse signal and a voltage corresponding to a current flowing through the first switch, so that the buck converter enters a corresponding working state, wherein the working state comprises an energy storage state and an energy release state.
Preferably, the control sub-module includes:
the pulse generator is used for outputting a preset pulse signal;
a comparison module, a first end of which is connected to a reference voltage, a second end of which is connected to the output end of the buck converter, and a third end of which is connected to the second end of the first switch, for determining the operating state of the buck converter based on the voltage at the output end of the buck converter and the voltage corresponding to the current flowing through the first switch, and outputting a level signal corresponding to the operating state of the buck converter;
the first end of the logic control module is connected with the second output end of the charging module, the second end of the logic control module is connected with the output end of the comparison module, the third end of the logic control module is connected with the output end of the pulse generator, the fourth end of the logic control module is connected with the second input end of the first driving module, and the fifth end of the logic control module is connected with the second input end of the second driving module, so that when the output signal of the charging module is at a first level, the first switch is controlled to be turned off based on the first driving module, and the second switch is controlled to be turned off based on the second driving module; when the output signal of the charging module is at a second level, the first switch and the second switch are controlled to be switched on and off based on a preset pulse signal output by the pulse generator and a level signal output by the comparison module, so that the buck converter enters a corresponding working state, wherein the working state comprises an energy storage state and an energy release state.
Preferably, the comparing module comprises:
the input end of the peak value detection module is connected with the second end of the first switch and used for detecting the current flowing through the first switch and converting the current into a corresponding voltage signal;
the error amplification module is connected with the output end of the buck converter at a first input end, connected with the reference voltage at a second input end, and used for outputting a voltage signal in an inverse proportion relation with the voltage at the output end of the buck converter based on the voltage at the output end of the buck converter;
the first input end of the comparator is connected with the output end of the peak detection module, the second input end of the comparator is connected with the output end of the error amplification module, and the output end of the comparator is connected with the second end of the logic control module and used for outputting a high level when the voltage corresponding to the current flowing through the first switch is greater than the output signal of the error amplification module so that the buck converter enters an energy release state; and when the voltage corresponding to the current flowing through the first switch is smaller than the output signal of the error amplification module, outputting a low level so that the buck converter enters an energy storage state when the output signal of the pulse generator is a high level.
Preferably, the method further comprises the following steps:
and the input end of the zero current detector is connected with the second end of the second switch, the output end of the zero current detector is connected with the control module, and the zero current detector is used for detecting the current of the second end of the second switch and controlling the second switch to be switched off based on the control module when the condition that the current flows backwards in the second end of the second switch is detected.
In order to solve the above technical problem, the present invention further provides a power chip, including the buck converter as described above.
The invention provides a buck converter, which is applied to a power supply chip and comprises a bootstrap capacitor, a charging module, a control module, a first switch and a second switch, wherein the charging module can detect the voltage at two ends of the bootstrap capacitor, when the power supply chip works under light load and is in a discontinuous conduction sleep mode, the cross voltage at two ends of the bootstrap capacitor is too low, the charging module is started, the charging process of the bootstrap capacitor is realized through a power supply, so that the voltage at two ends of the bootstrap capacitor reaches a state capable of enabling the first switch to be normally started, meanwhile, in the charging process of the bootstrap capacitor, the charging module can output a first level, the control module controls the first switch and the second switch to be switched off after receiving the first level, the false starting of the first switch and the second switch is prevented, the charging module additionally provides a path for charging the bootstrap capacitor, a lower bridge switch does not need to be forcibly started, the additional energy consumption caused by the conduction of the lower bridge switch is reduced, the power consumption of the power supply chip can be greatly reduced, the ripple conversion efficiency of the buck converter is improved, and the conversion efficiency of the power supply chip is improved.
The invention also provides a power supply chip which has the same beneficial effects as the buck converter.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed in the prior art and the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a buck converter according to the present invention;
FIG. 2 is a schematic diagram of another buck converter according to the present invention;
fig. 3 is a schematic signal waveform diagram of a working process of a charging module according to the present invention;
FIG. 4 is a schematic diagram of a signal waveform of an operation process of a buck converter according to the present invention;
fig. 5 is a schematic signal waveform diagram of an operation process of a buck converter according to the present invention.
Detailed Description
The core of the invention is to provide a buck converter and a power chip, when the power chip works under light load and is in a sleep mode of discontinuous conduction and under the condition of insufficient cross voltage at two ends of a bootstrap capacitor, a path is additionally provided for charging the bootstrap capacitor without forcibly turning on a lower bridge switch, so that the additional energy consumption caused by the conduction of the lower bridge switch is reduced, the power consumption of the power chip can be greatly reduced, the problems of ripple voltage increase output by the buck converter, reduction of the conversion efficiency of the power chip and the like are solved, and the conversion efficiency of the power chip is improved.
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1, fig. 1 is a schematic structural diagram of a buck converter according to the present invention;
referring to fig. 2, fig. 2 is a schematic structural diagram of another buck converter according to the present invention; VIN in fig. 2 denotes a power supply; GND represents ground; VOUT represents a voltage of an output terminal of the buck converter; VREF represents a voltage level provided by the reference voltage generator; BOOT represents a first terminal of the bootstrap capacitor; SW represents a second end of the bootstrap capacitor;
in order to solve the above technical problem, the present invention provides a buck converter applied to a power supply chip, where the buck converter includes a bootstrap capacitor CBOOT, a charging module 1, a control module 2, a first switch Q1, and a second switch Q2;
a first end of the bootstrap capacitor CBOOT is connected to a first input end of the charging module 1 and a first output end of the charging module 1, respectively, and a second end of the bootstrap capacitor CBOOT is connected to an output end of the buck converter, a second input end of the charging module 1, a first end of the first switch Q1, and a first end of the second switch Q2, respectively;
the second output end of the charging module 1 is connected with the first end of the control module 2, and the third input end is connected with the power supply, and is used for starting and outputting a first level when the voltages at the two ends of the bootstrap capacitor CBOOT are smaller than a preset voltage, so that the power supply can charge the bootstrap capacitor CBOOT; when the voltage at the two ends of the bootstrap capacitor CBOOT is greater than the preset voltage, the bootstrap capacitor CBOOT is disconnected and outputs a second level, and the first level and the second level are opposite;
the second end of the control module 2 is connected with the output end of the buck converter, the third end of the control module is connected with the second end of the first switch Q1, the fourth end of the control module is connected with the control end of the first switch Q1, and the fifth end of the control module is connected with the control end of the second switch Q2, and the control module is used for controlling the first switch Q1 and the second switch Q2 to be turned off when the output signal of the charging module 1 is at the first level; when the output signal of the charging module 1 is at a second level, controlling the first switch Q1 and the second switch Q2 to be switched on and off based on a preset pulse signal and a voltage corresponding to a current flowing through the first switch Q1, so that the buck converter enters a corresponding working state, wherein the working state comprises an energy storage state and an energy release state;
the second end of the first switch Q1 is connected to the power supply, and the second end of the second switch Q2 is grounded.
It can be understood that, the charging module 1 may detect voltages at two ends of the bootstrap capacitor CBOOT, when the voltages at two ends of the bootstrap capacitor CBOOT are lower than a preset voltage, at this time, the cross voltage at two ends of the bootstrap capacitor CBOOT is too low, the first switch Q1 serving as an upper bridge switch in the converter has a condition that the converter cannot be normally turned on, so the charging module 1 needs to be started, charge the bootstrap capacitor CBOOT through the power supply, and at the same time, the charging module 1 also outputs a first level, the control module 2 may control the first switch Q1 and the second switch Q2 to be turned off after receiving the first level, preventing in the process of charging the bootstrap capacitor CBOOT at the charging module 1, the first switch Q1 and the second switch Q2 may have a false start condition, thereby generating unnecessary additional loss, until after the charging is finished, the charging module 1 detects that the voltages at two ends of the bootstrap capacitor CBOOT have reached the preset voltage, at this time, the voltages at two ends of the bootstrap capacitor CBOOT may ensure the normal start of the first switch Q1, the charging module may stop receiving the charging control signal, and may adjust the working process of the converter according to the preset voltage, and the working process of the second level, and the working process of the converter may be performed according to the preset pulse. In fig. 2, the output signal of the charging module 1 is denoted by BST _ UVLO.
Specifically, the working process of the converter includes an energy storage process and an energy release process, when the output voltage of the converter is lower than a set voltage level, the control module 2 outputs a high level according to the preset pulse signal, at this time, the first switch Q1 is turned on, and at this time, the circuit of the converter starts to charge the internal inductor to perform the energy storage process. Because the converter can provide energy to the output end simultaneously in the energy storage process, the output voltage can rise when the energy on the inductor is larger than that of the load. When the control module 2 detects that the voltage corresponding to the current flowing through the first switch Q1 reaches a preset value, the output signal of the control module 2 is at a low level, the first switch Q1 is turned off, the second switch Q2 is turned on, and the energy releasing stage is started. In this stage, the output voltage continues to rise because the energy on the internal inductor is greater than the load until the energy on the inductor is lower than the load and the output voltage begins to drop. Until the output signal of the control module 2 turns to high level again, the second switch Q2 is turned off again and the first switch Q1 is turned on again, and the energy storage stage is entered. The converter repeats the above operations to adjust the output voltage level.
It should be noted that the preset voltage may be recorded into the charging module 1 in advance, the charging module 1 may have multiple choices for the comparison between the voltage at the two ends of the bootstrap capacitor CBOOT and the preset voltage, and may be implemented by using the simplest comparator, or may use other methods. The setting mode and specific implementation of the preset voltage are not particularly limited herein, and the specific value may also be adjusted according to the actual application requirements and the application environment, and the like, and the setting mode and specific implementation of the preset voltage are not particularly limited herein, and may be one preset voltage value, or may set a plurality of preset voltage values to perfect the control of the charging process of the bootstrap capacitor CBOOT by the charging module 1.
Specifically, the bootstrap capacitor CBOOT, the type and specific implementation of the charging module 1, the control module 2, the first switch Q1, and the second switch Q2 are not particularly limited herein, and there are various circuit structures that can implement the charging module 1 and the control module 2. It is understood that when the first level is a high level signal, the second signal is a low level signal; when the first level is a low level signal, the second signal is a high level signal; when the first switch Q1 and the second switch Q2 are NMOS (N-Metal-Oxide-Semiconductor) transistors, the first level should be a high level signal, so that the control module 2 controls the first switch Q1 and the second switch Q2 to be turned on and off based on the first level and the second level; the present application, such as the setting manner and the specific implementation of the first level and the second level, is not particularly limited herein.
Generally, a dc-to-dc buck converter combined with a dual N-channel switch is used in the power chip, and other types of converters may also be used, and the type and specific implementation of the buck converter are not particularly limited in this application, and may be selected according to different application requirements of the power chip.
It can be understood that the control module 2 can control the first switch Q1 and the second switch Q2 through the driving module, and also can control the first switch Q1 and the second switch Q2 based on the level signal, the specific implementation of the control module 2 is not particularly limited in this application, and the control mode and the detection mode have various choices and can be adjusted according to the specific circuit structure.
Specifically, for the control module 2, the setting mode and specific implementation of the first switch Q1 and the second switch Q2 are not particularly limited herein, the first switch Q1 and the second switch Q2 may adopt MOS (Metal-Oxide-Semiconductor Field-Effect Transistor ) tubes or other transistors, the conduction speed and the reaction speed of the transistors are very fast, the internal resistance is small, the power consumption is low, the power consumption of the converter can be effectively reduced, and the wide application of the converter is facilitated.
Especially, considering that a regulated power supply in the prior art charges a bootstrap capacitor CBOOT through a diode P, the conduction of the diode P also causes certain loss, and especially when the load of a power supply chip is in a light-load state, the loss caused by the diode P has a great influence on the conversion efficiency; the energy loss on this aspect has a great influence on the conversion efficiency of the power supply chip, so the components and parts used in the charging module 1 may be MOS transistors and other devices with small on-resistance and low power consumption, so as to further improve the conversion efficiency of the converter and reduce the working power consumption.
It can be understood that the regulated power supply is a regulated voltage inside the power chip, and since the power requirements of the components inside the converter are all relatively small, there is a regulation module inside the power chip, and the regulated power supply is obtained after the voltage of the power supply is reduced, so as to obtain a regulated power supply, such as VREG shown in fig. 2, for supplying power to the components inside the converter, and the application such as the specific implementation manner of the regulation module is not particularly limited herein, such as the Regulator module shown in fig. 2. VREF shown in fig. 2 indicates that the voltage level provided by the reference voltage generator is preset in advance, and may be obtained after being processed by the Bandgap module through the power supply, and the specific implementation of VREF is not particularly limited herein, and fig. 2 is only a specific embodiment.
The invention provides a buck converter, which is applied to a power supply chip, and comprises a bootstrap capacitor CBOOT, a charging module 1, a control module 2, a first switch Q1 and a second switch Q2, wherein the charging module 1 can detect the voltage at two ends of the bootstrap capacitor CBOOT, when the power supply chip works under light load and is in a sleep mode of discontinuous conduction, and the cross voltage at two ends of the bootstrap capacitor CBOOT is too low, the charging module 1 is started, the charging process of the bootstrap capacitor CBOOT is realized through a power supply, so that the voltage at two ends of the bootstrap capacitor CBOOT reaches a state capable of enabling the first switch Q1 to be normally started, meanwhile, in the charging process of the bootstrap capacitor CBOOT, the charging module 1 can output a first level, the control module 2 controls the first switch Q1 and the second switch Q2 to be turned off after receiving the first level, the mistaken starting of the first switch Q1 and the second switch Q2 is prevented, a path is additionally provided by the charging module 1 to carry out charging on the capacitor, the power supply chip without forced switching on of the first switch Q1, the power supply chip is greatly reduced, and the power supply chip is additionally consumed by the power supply chip, and the boost converter, and the power supply chip is greatly reduced.
On the basis of the above-described embodiments,
as a preferred embodiment, the charging module 1 includes:
a determining module 21, a first input end of which is connected to the first end of the bootstrap capacitor CBOOT, a second input end of which is connected to the second end of the bootstrap capacitor CBOOT, and output ends of which are respectively connected to the first input end of the starting module and the first end of the control module 2, for outputting a first level when the voltages at the two ends of the bootstrap capacitor CBOOT are smaller than a preset voltage; outputting a second level when the voltage at two ends of the bootstrap capacitor CBOOT is greater than a preset voltage, wherein the first level is opposite to the second level;
a starting module, a second input end of which is connected to the power supply, and an output end of which is connected to the first end of the bootstrap capacitor CBOOT, and is configured to start when the output signal of the determining module 21 is the first level, so that the power supply charges the bootstrap capacitor CBOOT; and is turned off when the output signal of the judging module 21 is at the second level.
It can be understood that the charging module 1 mainly needs to complete a determination process of whether the voltages at the two ends of the bootstrap capacitor CBOOT reach the preset voltage and a charging process of the bootstrap capacitor CBOOT, the determination module 21 is arranged in the charging module 1 to achieve the determination process of whether the voltages at the two ends of the bootstrap capacitor CBOOT reach the preset voltage, and the starting module is arranged to achieve the charging process of the bootstrap capacitor CBOOT; the judging module 21 judges the voltages at the two ends of the bootstrap capacitor CBOOT according to a preset voltage, and outputs a corresponding level signal to facilitate the subsequent work of the starting module and the control module 2; the starting module starts or disconnects according to the level signal output by the judging module 21, so as to realize the charging process of the bootstrap capacitor CBOOT. In fig. 2, the output signal of the determination module 21 is denoted by BST _ UVLO.
Specifically, the present application is not limited to the setting mode and specific implementation of the determination module 21 and the start module, and may be adjusted according to actual requirements and application scenarios, the determination module 21 may be implemented by using components such as a comparator, and the start module may be implemented by using a switching device, and particularly, when the start module uses devices with low power consumption such as an MOS transistor, the power consumption may be further reduced, the problems of increase of ripple voltage output by the buck converter and reduction of conversion efficiency of the power chip may be solved, and the conversion efficiency of the power chip may be improved.
As a specific embodiment, the charging module 1 is provided with a determining module 21 for determining whether the voltage at the two ends of the bootstrap capacitor CBOOT reaches a preset voltage, and a starting module for charging the bootstrap capacitor CBOOT; the two processes of the charging module 1 to be completed are completed through different module settings, so that the charging module 1 is effectively realized, the circuit structure of the charging module 1 is more hierarchical, clearer and clearer, the realization of the control process of the follow-up control module 2 and the orderly proceeding of the charging process of the bootstrap capacitor CBOOT are facilitated, and the normal work and the conversion process of the buck converter are ensured.
As a preferred embodiment, the start module comprises:
a starting switch, wherein a first end is connected with a power supply, and a second end is connected with a first end of the bootstrap capacitor CBOOT;
the input end of the level-voltage converter 22 is connected with the output end of the judging module 21, and the output end of the level-voltage converter is connected with the control end of the starting switch, so that the starting switch is controlled to be turned on when the output signal of the judging module 21 is at the first level, and the power supply is enabled to charge the bootstrap capacitor CBOOT; and when the output signal of the judging module 21 is at the second level, controlling the starting switch to be turned off.
It can be understood that the starting module can realize the control of whether the bootstrap capacitor CBOOT is charged through the switching device of the starting switch, and meanwhile, because the range of the input voltage of the dc-dc buck converter is large, generally about 5V to 80V, a voltage level converter needs to be set to convert the output signal of the judging module 21 into a control signal in a suitable voltage range, so as to avoid the damage of the starting switch due to the excessive voltage, and especially when the starting switch is a transistor, the transistor can be effectively prevented from being broken down.
Specifically, the types and specific implementations of the start switch and the voltage level converter are not particularly limited in this application, and the start switch may be implemented by selecting devices such as a MOS transistor, or other switching devices may be used, and the voltage level converter may have various types and may be selected. The power supply to which the start switch is connected is not particularly limited in this application, and various options exist.
As a specific embodiment, whether the bootstrap capacitor CBOOT is charged or not is controlled by the switch device, i.e., the start switch, and meanwhile, the voltage level converter is added, so that the condition that the start switch is damaged due to the large voltage range of the converter is prevented.
As a preferred embodiment, the start switch includes:
a first end of the first starting switch W1 is connected with a power supply;
and a first end of the second starting switch W2 is connected with a second end of the first starting switch W1, and a second end of the second starting switch W is connected with a first end of the bootstrap capacitor CBOOT.
Considering that when the starting switch is a single switching device, both ends of the switching device may be high voltage, which may cause the voltage withstand problem of the switching device or the occurrence of situations such as current backflow due to large voltage, the function of the starting switch is realized through the cooperation of the first starting switch W1 and the second starting switch W2, and when the starting switch needs to be turned on, the first starting switch W1 and the second starting switch W2 are turned on simultaneously to realize the charging process of the bootstrap capacitor CBOOT. Specifically, the types and specific implementation manners of the first start switch W1 and the second start switch W2 are not particularly limited in this application, and may be implemented by using NMOS transistors, or may be adjusted according to actual application requirements and application environments.
As a specific embodiment, the function of the starting switch is realized through the cooperation of the first starting switch W1 and the second starting switch W2, so that the conditions of too low voltage withstanding value and possible current backflow caused by a single switching device are effectively avoided, the normal working process of the starting module is ensured, the realization of the charging process of the bootstrap capacitor CBOOT by the charging module 1 is effectively ensured, the normal working of the buck converter is further ensured, and the reliability and the safety of the whole circuit are improved.
As a preferred embodiment of the method according to the invention,
the preset voltage includes: the voltage regulator comprises a first preset voltage and a second preset voltage, wherein the second preset voltage is greater than the first preset voltage;
correspondingly, the voltage at the two ends of the bootstrap capacitor CBOOT is smaller than the preset voltage, including:
the voltage at two ends of the bootstrap capacitor CBOOT is smaller than a first preset voltage;
the voltage at the two ends of the bootstrap capacitor CBOOT is greater than a preset voltage, including:
the voltage across the bootstrap capacitor CBOOT is greater than the second predetermined voltage.
Considering that a single preset voltage can cause frequent starting and turning-off actions of the charging module 1, the charging module 1 can be internally provided with a first preset voltage and a second preset voltage, the second preset voltage is greater than the first preset voltage, in the charging process of the bootstrap capacitor CBOOT, charging is stopped until voltages at two ends of the bootstrap capacitor CBOOT reach the second preset voltage, charging is started only when the voltages at the two ends of the bootstrap capacitor CBOOT are detected to be lower than the first preset voltage, the two preset voltages reach a hysteresis control effect, continuous switching of output signals of the charging module 1 is avoided, and misoperation of the control module 2 is caused.
Specifically, the first preset voltage and the second preset voltage are set in the charging module 1 in advance, and the specific setting method and implementation manner of the first preset voltage and the second preset voltage are not particularly limited herein, such as VL and VH shown in fig. 2, where VL in fig. 2 represents the first preset voltage, and VH represents the second preset voltage; the specific values of the first preset voltage and the second preset voltage may be adjusted according to different types of the bootstrap capacitor CBOOT and application requirements, which is not limited herein.
Referring to fig. 3, fig. 3 is a schematic signal waveform diagram of a working process of a charging module according to the present invention. BOOT-SW represents the voltage difference across bootstrap capacitor CBOOT; VL represents a first preset voltage; VH represents a second preset voltage; BST _ UVLO represents a level signal of the output of the charging module 1; fig. 3 shows how the charging module 1 adjusts the output level signal according to the first preset voltage and the second preset voltage.
Considering that a single preset voltage can cause frequent start and stop actions of the charging module 1, a first preset voltage and a second preset voltage can be set inside the charging module 1, and the second preset voltage is greater than the first preset voltage, so that the switching frequency of the charging module 1 to the charging process is reduced, the power loss of the charging module 1 is reduced, the problems of ripple voltage rise output by the buck converter, reduction of the conversion efficiency of the power chip and the like are further solved, and the conversion efficiency of the power chip is improved.
As a preferred embodiment, the control module 2 comprises:
the first input end of the first driving module D1 is connected with a voltage-stabilized power supply, and the output end of the first driving module D1 is respectively connected with the control end and the first end of the first switch Q1;
a first input end of the second driving module D2 is connected with a voltage-stabilized power supply, and an output end of the second driving module D2 is respectively connected with a control end and a first end of the second switch Q2;
the first end of the control sub-module is connected with the second output end of the charging module 1, the second end of the control sub-module is connected with the output end of the buck converter, the third end of the control sub-module is connected with the second end of the first switch Q1, the fourth end of the control sub-module is connected with the second input end of the first driving module D1, the fifth end of the control sub-module is connected with the second input end of the second driving module D2, and the control sub-module is used for controlling the first switch Q1 to be turned off based on the first driving module D1 and controlling the second switch Q2 to be turned off based on the second driving module D2 when the output signal of the charging module 1 is at the first level; when the output signal of the charging module 1 is at the second level, the first switch Q1 and the second switch Q2 are controlled to be turned on and off based on the preset pulse signal and the voltage corresponding to the current flowing through the first switch Q1, so that the buck converter enters a corresponding working state, wherein the working state comprises an energy storage state and an energy release state.
It can be understood that the control module 2 mainly needs to complete the control process of the first switch Q1 and the second switch Q2 and the detection process of the voltage corresponding to the current flowing through the first switch Q1, and the control submodule is arranged in the control module 2 to realize the detection process of the voltage corresponding to the current flowing through the first switch Q1; the first driving module D1 is arranged to realize the control process of the first switch Q1, the second driving module D2 is arranged to realize the control process of the second switch Q2, and the first driving module D1 and the second driving module D2 directly control the first switch Q1 and the second switch Q2 to execute corresponding on-off operation through the output signals of the control sub-modules.
Specifically, for the control sub-module, the setting mode, the specific implementation, and the like of the first driving module D1 and the second driving module D2 are not particularly limited herein, and may be adjusted according to actual requirements and application scenarios, the control sub-module is generally implemented by components such as a comparator, and the first driving module D1 and the second driving module D2 may be implemented by driving a control circuit and the like.
As a specific embodiment, the control module 2 includes a control submodule, a first driving module D1 and a second driving module D2, and the control submodule implements a detection process of a voltage corresponding to a current flowing through the first switch Q1; the first driving module D1 realizes the control process of the first switch Q1, and the second driving module D2 realizes the control process of the second switch Q2. The two processes to be completed by the control module 2 are completed through different module settings, so that the control module 2 is effectively realized, the circuit structure of the control module 2 is more hierarchical, clearer and clearer, the control process of the subsequent control module 2 is facilitated, and the normal work and conversion process of the buck converter are ensured.
As a preferred embodiment, the control sub-module includes:
the pulse generator is used for outputting a preset pulse signal;
the comparison module is connected with the reference voltage at a first end, connected with the output end of the buck converter at a second end, and connected with the second end of the first switch Q1 at a third end, and is used for determining the working state of the buck converter based on the voltage at the output end of the buck converter and the voltage corresponding to the current flowing through the first switch Q1 and outputting a level signal corresponding to the working state of the buck converter;
the logic control module 23 has a first end connected to the second output end of the charging module 1, a second end connected to the output end of the comparison module, a third end connected to the output end of the pulse generator, a fourth end connected to the second input end of the first driving module D1, and a fifth end connected to the second input end of the second driving module D2, and is configured to control the first switch Q1 to be turned off based on the first driving module D1 and the second switch Q2 to be turned off based on the second driving module D2 when the output signal of the charging module 1 is at the first level; when the output signal of the charging module 1 is at the second level, the first switch Q1 and the second switch Q2 are controlled to be turned on and off based on the preset pulse signal output by the pulse generator and the level signal output by the comparing module, so that the buck converter enters the corresponding working state, wherein the working state comprises an energy storage state and an energy release state.
It can be understood that the control submodule needs to determine the working state of the buck converter through a preset pulse signal and a voltage corresponding to a current flowing through the first switch Q1, and outputs a corresponding level signal to control the first driving module D1 and the second driving module D2, and the control submodule is provided with a comparison module to determine the working state of the buck converter and outputs a level signal corresponding to the working state of the buck converter; and then the logic control module 23 controls the first driving module D1 and the second driving module D2 to realize the control of the first switch Q1 and the second switch Q2 according to the output signal of the charging module 1, the output signal of the pulse generator and the output signal of the comparing module.
Specifically, the comparison module determines the time for which the first switch Q1 is turned off and the second switch Q2 is turned on by the voltage at the output terminal of the buck converter and the voltage corresponding to the current flowing through the first switch Q1. Taking fig. 2 as an example, when the voltage corresponding to the current flowing through the first switch Q1 plus the slope compensation signal is greater than the output signal of the error amplifier, the comparing module outputs a high level signal, and the logic control module 23 controls the first switch Q1 to turn off and the second switch Q2 to turn on, so that the buck converter enters the energy release stage. The specific implementation process of how the comparison module determines the operating state of the converter is not particularly limited in this application.
Specifically, the present application does not limit the setting and specific implementation of the pulse generator, the comparison module and the logic control module 23, and may be adjusted according to actual requirements and application scenarios, the comparison module is generally implemented by a comparator and other components, and the logic control module 23 may be implemented by a digital logic circuit and other manners; the pulse generator may be implemented by a crystal oscillator OSC, such as the OSC shown in fig. 2.
As a specific embodiment, the control submodule includes a pulse generator, a comparison module and a logic control module 23, the comparison module realizes the determination process of the working state of the buck converter, and the logic control module 23 realizes the control process of the first driving module D1 and the second driving module D2 according to the output signal of the charging module 1, the output signal of the pulse generator and the output signal of the comparison module; the control submodule is arranged through different modules, so that the control submodule is effectively realized, the circuit structure of the control submodule is clearer and clearer, the control process of the follow-up control submodule and the control module 2 is favorably realized, and the normal work and the conversion process of the buck converter are ensured.
As a preferred embodiment, the comparison module comprises:
the input end of the peak value detection module is connected with the second end of the first switch Q1 and is used for detecting the current flowing through the first switch Q1 and converting the current into a corresponding voltage signal;
the error amplification module is connected with the output end of the buck converter through a first input end and connected with the reference voltage through a second input end, and is used for outputting a voltage signal in an inversely proportional relation with the voltage at the output end of the buck converter based on the voltage at the output end of the buck converter;
a comparator U2, a first input end of which is connected to the output end of the peak detection module, a second input end of which is connected to the output end of the error amplification module, and an output end of which is connected to the second end of the logic control module 23, and configured to output a high level when a voltage corresponding to a current flowing through the first switch Q1 is greater than an output signal of the error amplification module, so that the buck converter enters an energy release state; when the voltage corresponding to the current flowing through the first switch Q1 is smaller than the output signal of the error amplification module, a low level is output, so that the buck converter enters an energy storage state when the output signal of the pulse generator is a high level.
It can be understood that, the comparison module needs to compare the voltage at the output end of the buck converter with the reference voltage, and meanwhile, the peak detection module is provided to detect the voltage corresponding to the current flowing through the first switch Q1, and then the error amplification module determines the reference voltage, and finally the comparator U2 is used to compare the voltage at the output end of the buck converter with the reference voltage.
Specifically, the process of determining the reference voltage by the error amplification module is mainly realized by comparing the voltage signal output by the buck converter with a preset voltage level, the error amplification module outputs a voltage signal in an inverse proportion relation with the voltage at the output end of the buck converter after comparing the voltage signal with the preset voltage level, and the voltage signal is subsequently used as the reference voltage and compared with the voltage corresponding to the current flowing through the first switch Q1. The specific operation and implementation of the error amplification module to determine the reference voltage are not particularly limited in this application, and various implementations exist.
The types and specific implementation manners of the peak detection module, the error amplification module, and the comparator U2 are not particularly limited in this application, and may be adjusted according to actual requirements and application scenarios, and various implementation manners exist in specific circuit structures. Taking fig. 2 as an example, the Slope Compensation, peak Current Sense and corresponding adder in fig. 2 together form a Peak detection module, the error amplifier U1 and corresponding Compensation resistor and the like form an error amplification module, and the PFM Detector is a manner for reducing circuit loss.
As a specific embodiment, the comparison module includes a peak detection module, an error amplification module and a comparator U2, the detection of the voltage corresponding to the current flowing through the first switch Q1 is realized by the peak detection module, the determination of the reference voltage is realized by the error amplification module, and finally the comparison process between the voltage at the output end of the buck converter and the reference voltage is realized by the comparator U2. The three processes to be completed by the comparison module are completed through different module settings, so that the comparison module is effectively realized, the circuit structure of the comparison module is clearer and clearer, the realization of the comparison process of the subsequent comparison module is facilitated, and the normal work and the conversion process of the buck converter are further ensured.
As a preferred embodiment, further comprising:
and the input end of the zero current detector 24 is connected with the second end of the second switch Q2, and the output end of the zero current detector is connected with the control module 2, and is used for detecting the current of the second end of the second switch Q2 and controlling the second switch Q2 to be switched off based on the control module 2 when the condition that the current flows backwards at the second end of the second switch Q2 is detected.
Considering that there may be a current backflow condition at the second end of the second switch Q2, a zero current detector 24 is disposed at the second end of the second switch Q2 for detecting a current condition at the second end of the second switch Q2, and the zero current detector 24 is connected to the control module 2, so as to ensure that when there is a current backflow condition at the second end of the second switch Q2, the control module 2 can rapidly control the second switch Q2 to be turned off, so as to prevent a more serious condition caused by the current backflow. The type and specific implementation of the zero-current detector 24 are not particularly limited herein, and may be adjusted according to the actual application requirements and the application environment.
Considering that the second end of the second switch Q2 may have a current backflow situation, the second end of the second switch Q2 is provided with the zero current detector 24 connected to the control module 2, so as to ensure that when the second end of the second switch Q2 is detected to have the current backflow situation, the control module 2 can rapidly control the second switch Q2 to be turned off, prevent the occurrence of a more serious situation caused by the current backflow, ensure the normal working process of the second switch Q2, further ensure the normal operation of the buck converter, and improve the reliability and safety of the whole circuit.
It should be understood that, referring to fig. 4 and fig. 5, fig. 4 is a schematic signal waveform diagram of an operation process of a buck converter provided in the present invention; FIG. 5 is a schematic diagram of a signal waveform of an operation process of a buck converter according to the present invention; in the figure, BOOT-SW represents the voltage difference across bootstrap capacitor CBOOT; VL represents a first preset voltage; VH represents a second preset voltage; vgs of Q1 represents the voltage of the control terminal of the first switch Q1; vgs of Q2 represents the voltage of the control terminal of the second switch Q2; IL represents the charging current of the bootstrap capacitor CBOOT; the circled portion in fig. 4 represents the extra energy loss due to the conduction of the diode P and the second switch Q2; BST _ UVLO represents a level signal of the output of the charging module 1; vgs of W1, W2 denotes the voltage of the control terminals of the first and second start switches W1, W2; the circled portion in fig. 5 indicates that no additional energy loss is generated due to the charging process of the bootstrap capacitor CBOOT through the charging module 1. The difference between the energy loss during the charging process of the bootstrap capacitor CBOOT through the diode P and the second switch Q2 and the charging process through the charging module 1 can be clearly seen from the comparison between fig. 4 and fig. 5, and the effectiveness of the charging module 1 is further illustrated.
In order to solve the above technical problem, the present invention further provides a power chip, including the buck converter as described above.
It is understood that the power chip is mainly implemented by a buck converter, and the type and specific implementation of the buck converter are not particularly limited in this application, and may be selected according to different application requirements of the power chip.
For the introduction of the power chip provided by the present invention, reference is made to the embodiment of the buck converter, and the present invention is not repeated herein.
It should also be noted that, in this specification, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a," "8230," "8230," or "comprising" does not exclude the presence of additional like elements in a process, method, article, or apparatus that comprises the element.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A buck converter is applied to a power supply chip and comprises a bootstrap capacitor, a charging module, a control module, a first switch and a second switch;
a first end of the bootstrap capacitor is connected to a first input end of the charging module and a first output end of the charging module, respectively, and a second end of the bootstrap capacitor is connected to an output end of the buck converter, a second input end of the charging module, and a first end of the first switch and a first end of the second switch, respectively;
the second output end of the charging module is connected with the first end of the control module, and the third input end of the charging module is connected with a power supply, and the charging module is used for starting and outputting a first level when the voltage at the two ends of the bootstrap capacitor is smaller than a preset voltage, so that the power supply can charge the bootstrap capacitor; when the voltage at two ends of the bootstrap capacitor is greater than a preset voltage, the bootstrap capacitor is disconnected and outputs a second level, and the first level and the second level are opposite;
the second end of the control module is connected with the output end of the buck converter, the third end of the control module is connected with the second end of the first switch, the fourth end of the control module is connected with the control end of the first switch, and the fifth end of the control module is connected with the control end of the second switch, and is used for controlling the first switch and the second switch to be turned off when the output signal of the charging module is at a first level; when the output signal of the charging module is at a second level, controlling the first switch and the second switch to be switched on and off based on a preset pulse signal and a voltage corresponding to a current flowing through the first switch, so that the buck converter enters a corresponding working state, wherein the working state comprises an energy storage state and an energy release state;
the second end of the first switch is connected with a power supply, and the second end of the second switch is grounded.
2. The buck converter according to claim 1, wherein the charging module includes:
a first input end of the judgment module is connected with a first end of the bootstrap capacitor, a second input end of the judgment module is connected with a second end of the bootstrap capacitor, and an output end of the judgment module is respectively connected with a first input end of the starting module and a first end of the control module and is used for outputting a first level when the voltage at two ends of the bootstrap capacitor is smaller than a preset voltage; outputting a second level when the voltage at two ends of the bootstrap capacitor is greater than a preset voltage, wherein the first level is opposite to the second level;
the second input end of the starting module is connected with a power supply, the output end of the starting module is connected with the first end of the bootstrap capacitor, and the starting module is used for starting when the output signal of the judging module is a first level so that the power supply can charge the bootstrap capacitor; and when the output signal of the judging module is the second level, the circuit is disconnected.
3. The buck converter according to claim 2, wherein the start-up module includes:
a starting switch, wherein a first end of the starting switch is connected with a power supply, and a second end of the starting switch is connected with a first end of the bootstrap capacitor;
the input end of the level voltage converter is connected with the output end of the judging module, the output end of the level voltage converter is connected with the control end of the starting switch, and the level voltage converter is used for controlling the starting switch to be conducted when the output signal of the judging module is a first level so as to enable the power supply to charge the bootstrap capacitor; and when the output signal of the judging module is a second level, the starting switch is controlled to be turned off.
4. The buck converter according to claim 3, wherein the start switch comprises:
the first end of the first starting switch is connected with a power supply;
and a first end of the second starting switch is connected with a second end of the first starting switch, and a second end of the second starting switch is connected with a first end of the bootstrap capacitor.
5. Buck converter according to claim 1,
the preset voltage includes: the voltage regulator comprises a first preset voltage and a second preset voltage, wherein the second preset voltage is greater than the first preset voltage;
correspondingly, the voltage at the two ends of the bootstrap capacitor is smaller than a preset voltage, and the method includes:
the voltage at two ends of the bootstrap capacitor is smaller than a first preset voltage;
the voltage at the two ends of the bootstrap capacitor is greater than a preset voltage, and the bootstrap capacitor comprises:
and the voltage of two ends of the bootstrap capacitor is greater than a second preset voltage.
6. The buck converter according to claim 1, wherein the control module includes:
the first input end of the first driving module is connected with a voltage-stabilized power supply, and the output end of the first driving module is respectively connected with the control end and the first end of the first switch;
the first input end of the second driving module is connected with the stabilized voltage power supply, and the output end of the second driving module is respectively connected with the control end and the first end of the second switch;
the control sub-module is connected with the second output end of the charging module, the second end of the control sub-module is connected with the output end of the buck converter, the third end of the control sub-module is connected with the second end of the first switch, the fourth end of the control sub-module is connected with the second input end of the first driving module, and the fifth end of the control sub-module is connected with the second input end of the second driving module, and is used for controlling the first switch to be turned off based on the first driving module and controlling the second switch to be turned off based on the second driving module when the output signal of the charging module is at the first level; when the output signal of the charging module is at a second level, the first switch and the second switch are controlled to be switched on and off based on a preset pulse signal and a voltage corresponding to a current flowing through the first switch, so that the buck converter enters a corresponding working state, wherein the working state comprises an energy storage state and an energy release state.
7. The buck converter according to claim 6, wherein the control sub-module includes:
the pulse generator is used for outputting a preset pulse signal;
a comparison module, a first end of which is connected to a reference voltage, a second end of which is connected to the output end of the buck converter, and a third end of which is connected to the second end of the first switch, for determining the operating state of the buck converter based on the voltage at the output end of the buck converter and the voltage corresponding to the current flowing through the first switch, and outputting a level signal corresponding to the operating state of the buck converter;
the first end of the logic control module is connected with the second output end of the charging module, the second end of the logic control module is connected with the output end of the comparison module, the third end of the logic control module is connected with the output end of the pulse generator, the fourth end of the logic control module is connected with the second input end of the first driving module, and the fifth end of the logic control module is connected with the second input end of the second driving module and is used for controlling the first switch to be turned off based on the first driving module and controlling the second switch to be turned off based on the second driving module when the output signal of the charging module is at the first level; when the output signal of the charging module is at a second level, the first switch and the second switch are controlled to be switched on and off based on a preset pulse signal output by the pulse generator and a level signal output by the comparison module, so that the buck converter enters a corresponding working state, wherein the working state comprises an energy storage state and an energy release state.
8. The buck converter according to claim 7, wherein the comparison module includes:
the input end of the peak value detection module is connected with the second end of the first switch and used for detecting the current flowing through the first switch and converting the current into a corresponding voltage signal;
the error amplification module is connected with the output end of the buck converter at a first input end, connected with the reference voltage at a second input end, and used for outputting a voltage signal in an inverse proportion relation with the voltage at the output end of the buck converter based on the voltage at the output end of the buck converter;
the first input end of the comparator is connected with the output end of the peak detection module, the second input end of the comparator is connected with the output end of the error amplification module, and the output end of the comparator is connected with the second end of the logic control module and used for outputting a high level when the voltage corresponding to the current flowing through the first switch is greater than the output signal of the error amplification module so that the buck converter enters an energy release state; and when the voltage corresponding to the current flowing through the first switch is smaller than the output signal of the error amplification module, outputting a low level so that the buck converter enters an energy storage state when the output signal of the pulse generator is a high level.
9. The buck converter according to any one of claims 1 to 8, further comprising:
and the input end of the zero current detector is connected with the second end of the second switch, the output end of the zero current detector is connected with the control module, and the zero current detector is used for detecting the current of the second end of the second switch and controlling the second switch to be switched off based on the control module when the condition that the current flows backwards at the second end of the second switch is detected.
10. A power supply chip comprising the buck converter according to any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310097450.6A CN115882727A (en) | 2023-02-10 | 2023-02-10 | Step-down converter and power chip |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310097450.6A CN115882727A (en) | 2023-02-10 | 2023-02-10 | Step-down converter and power chip |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115882727A true CN115882727A (en) | 2023-03-31 |
Family
ID=85761023
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310097450.6A Pending CN115882727A (en) | 2023-02-10 | 2023-02-10 | Step-down converter and power chip |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115882727A (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130265016A1 (en) * | 2012-04-06 | 2013-10-10 | Shao-Te Chang | Direct Current Converter for Bootstrap Circuit |
| JP2014023269A (en) * | 2012-07-18 | 2014-02-03 | Renesas Electronics Corp | Semiconductor integrated circuit and method of operating the same |
| CN204290695U (en) * | 2014-08-11 | 2015-04-22 | 成都芯源***有限公司 | Bootstrap voltage refresh control circuit and voltage conversion circuit thereof |
| US20150188425A1 (en) * | 2013-12-27 | 2015-07-02 | Anpec Electronics Corporation | Buck converter and control method therefor |
| CN204721209U (en) * | 2015-04-09 | 2015-10-21 | 杭州宽福科技有限公司 | A kind of dc-dc chip preventing inductive current from pouring in down a chimney |
| CN106817024A (en) * | 2015-11-30 | 2017-06-09 | 展讯通信（上海）有限公司 | Lift the buck power converter of transient response performance |
| CN109742839A (en) * | 2019-03-19 | 2019-05-10 | 浪潮商用机器有限公司 | A kind of charging control circuit and system of bootstrap capacitor |
| CN110994996A (en) * | 2019-12-31 | 2020-04-10 | 思瑞浦微电子科技（苏州）股份有限公司 | Asynchronous step-down DCDC chip and bootstrap circuit based on asynchronous step-down DCDC chip |
| CN113937982A (en) * | 2021-10-20 | 2022-01-14 | 上海数明半导体有限公司 | Switch power supply circuit, method, device, equipment and medium for charging bootstrap capacitor |
-
2023
- 2023-02-10 CN CN202310097450.6A patent/CN115882727A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130265016A1 (en) * | 2012-04-06 | 2013-10-10 | Shao-Te Chang | Direct Current Converter for Bootstrap Circuit |
| JP2014023269A (en) * | 2012-07-18 | 2014-02-03 | Renesas Electronics Corp | Semiconductor integrated circuit and method of operating the same |
| US20150188425A1 (en) * | 2013-12-27 | 2015-07-02 | Anpec Electronics Corporation | Buck converter and control method therefor |
| CN204290695U (en) * | 2014-08-11 | 2015-04-22 | 成都芯源***有限公司 | Bootstrap voltage refresh control circuit and voltage conversion circuit thereof |
| CN204721209U (en) * | 2015-04-09 | 2015-10-21 | 杭州宽福科技有限公司 | A kind of dc-dc chip preventing inductive current from pouring in down a chimney |
| CN106817024A (en) * | 2015-11-30 | 2017-06-09 | 展讯通信（上海）有限公司 | Lift the buck power converter of transient response performance |
| CN109742839A (en) * | 2019-03-19 | 2019-05-10 | 浪潮商用机器有限公司 | A kind of charging control circuit and system of bootstrap capacitor |
| CN110994996A (en) * | 2019-12-31 | 2020-04-10 | 思瑞浦微电子科技（苏州）股份有限公司 | Asynchronous step-down DCDC chip and bootstrap circuit based on asynchronous step-down DCDC chip |
| CN113937982A (en) * | 2021-10-20 | 2022-01-14 | 上海数明半导体有限公司 | Switch power supply circuit, method, device, equipment and medium for charging bootstrap capacitor |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7957165B2 (en) | DC-DC converter with a plurality of soft-start control circuits | |
| USRE41061E1 (en) | High efficiency linear regulator | |
| US8248040B2 (en) | Time-limiting mode (TLM) for an interleaved power factor correction (PFC) converter | |
| US8000117B2 (en) | Buck boost function based on a capacitor bootstrap input buck converter | |
| US8330442B2 (en) | DC to DC converter and method for reducing overshoot | |
| EP1926199B1 (en) | Buck converter with inductor pre-energizing | |
| US8698475B2 (en) | Switching-mode power supply with ripple mode control and associated methods | |
| US8138731B2 (en) | Power regulation for large transient loads | |
| US7098632B2 (en) | Controller in a voltage mode buck converter for implementing a mode-switch function and an over-current protection by a multifunction pin and method thereof | |
| KR101264558B1 (en) | Switching regulator and operation control method thereof | |
| US7298119B1 (en) | Step-up/step-down (buck/boost) switching regulator control methods | |
| US8513920B2 (en) | Charge current reduction for current limited switched power supply | |
| JP3335587B2 (en) | DC-DC converter circuit | |
| US11218076B2 (en) | Ultra-low Iq buck converter with switchable error amplifier | |
| CN107959421B (en) | BUCK-BOOST type direct current converter and control method thereof | |
| US7579817B2 (en) | Constant-voltage circuit capable of reducing time required for starting, semiconductor apparatus including constant-voltage circuit, and control method of constant-voltage circuit | |
| JPH11196541A (en) | Power supply unit | |
| CN112994455A (en) | Buck-boost converter and control method thereof | |
| US20110001460A1 (en) | Lower power controller for dc to dc converters | |
| JP4379396B2 (en) | Buck-boost chopper type DC-DC converter | |
| CN113497559B (en) | Converter circuit, corresponding device and method | |
| US11705811B2 (en) | Buck-boost converter and hybrid control method | |
| US11152861B2 (en) | Multiphase converter design with multi-path phase management | |
| JP5951358B2 (en) | Charging control circuit and charging circuit | |
| JP3132614B2 (en) | DC-DC converter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20230331 |
|
| RJ01 | Rejection of invention patent application after publication |