Drive circuit, DC voltage conversion circuit, and DC voltage conversion system

Abstract

The embodiment of the present application provides a driving circuit, a direct current voltage conversion circuit and a direct current voltage conversion system. The driving circuit is used for driving a first switch tube arranged in a switching power supply circuit, and comprises: a voltage generation module, which is used for generating a source bias voltage of the first switch tube and generating a gate drive voltage of the first switch tube, and the gate drive voltage is used for turning on the first switch tube; a voltage pull-up module connected with the voltage generation module, which is used for pulling up the gate drive voltage and outputting a pull-up gate drive voltage; and a voltage sampling module comprising a second switch tube, the gate of the second switch tube is connected with the pull-up gate drive voltage, the source of the second switch tube is connected with the source bias voltage, and the voltage sampling module samples a drain voltage of the first switch tube when the second switch tube is turned on. The scheme of the embodiment of the present application provides a larger gate-source voltage selection range for the first switch tube.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of electronic circuit technology, and in particular to a driving circuit, a DC voltage conversion circuit, and a DC voltage conversion system. Background Technology

[0002] A DC-DC (Direct-to-Direct-Voltage) system is a circuit that converts a DC power supply of one voltage level to a DC power supply of another voltage level. A DC-DC system is formed by connecting components such as inductors, capacitors, resistors, and switching transistors. Based on the voltage conversion relationship, it is divided into two categories: boost power supplies and buck power supplies. By controlling the switching transistors through a drive circuit, the DC output voltage can be flexibly obtained according to the DC input voltage.

[0003] In the driving circuit, the switching transistor can be made of discrete components or constructed from integrated devices using semiconductor integration technology, so as to be integrated with other semiconductor devices in the driving circuit.

[0004] When a switching transistor is constructed as a discrete device, its gate and source can withstand higher gate-source voltages, resulting in higher performance; however, the device size is larger. When a switching transistor is constructed as an integrated device, its device size is smaller; however, its gate and source cannot withstand higher gate-source voltages, resulting in poorer performance.

[0005] Therefore, balancing the size and performance of switching transistors has become an urgent technical problem to be solved. Summary of the Invention

[0006] In view of this, embodiments of the present invention provide a driving circuit, a DC voltage conversion circuit, and a DC voltage conversion system to at least partially solve the above-mentioned problems.

[0007] According to a first aspect of the present invention, a driving circuit is provided for driving a first switching transistor disposed in a switching power supply circuit. The driving circuit includes: a voltage generation module for generating a source bias voltage of the first switching transistor and generating a gate driving voltage of the first switching transistor, the gate driving voltage being used to turn on the first switching transistor; a voltage pull-up module connected to the voltage generation module for pulling up the gate driving voltage and outputting a pull-up gate driving voltage; and a voltage sampling module including a second switching transistor, the gate of the second switching transistor being connected to the pull-up gate driving voltage, and the source of the second switching transistor being connected to the source bias voltage, the voltage sampling module sampling the drain voltage of the first switching transistor when the second switching transistor is turned on.

[0008] In another implementation of the present invention, the voltage sampling module further includes a second resistor, the source of the second switch is connected to one end of the second resistor and the sampling terminal, the other end of the second resistor is connected to the source bias voltage, and the drain of the second switch is connected to the drain of the first switch.

[0009] In another implementation of the present invention, the voltage pull-up module includes a third switch and a third resistor. The gate of the third switch is connected to the gate drive voltage. One end of the third resistor is connected to the source bias voltage. The other end of the third resistor is connected to the source of the third switch and the gate of the second switch. The drain of the third switch is grounded.

[0010] In another implementation of the present invention, the voltage pull-up module further includes a fourth resistor, which is connected in series between the third resistor and the source of the third switching transistor.

[0011] In another implementation of the present invention, the voltage pull-up module further includes a fifth resistor, one end of which is connected to the drain of the third switching transistor, and the other end of which is grounded.

[0012] In another implementation of the present invention, the voltage pull-up module includes a first diode, the cathode of the first diode is connected to the source bias voltage, and the anode of the first diode is connected between the source of the third switch and the third resistor.

[0013] In another implementation of the present invention, the voltage generation module includes a fourth switch and a fifth switch. The source of the fourth switch is connected to the source bias voltage, the drain of the fourth switch is connected to the source of the fifth switch, the drain of the fifth switch is grounded, and the gate of the third switch is connected to the drain of the fourth switch and the source of the fifth switch. The gate of the fourth switch receives a first control voltage and is turned on according to the first control voltage, while the gate of the fifth switch is turned on according to a second control voltage.

[0014] In another implementation of the present invention, the voltage generation module further includes a sixth switch and a pull-down resistor, the pull-down resistor being connected between the source of the sixth switch and the source bias voltage, the gate of the fifth switch being connected to the source of the sixth switch, the gate of the sixth switch receiving a second control voltage and being turned on according to the second control voltage.

[0015] In another implementation of the present invention, the voltage generation module further includes a first resistor connected between the source bias voltage and the gate of the fifth switching transistor.

[0016] According to a second aspect of the present invention, a DC-DC voltage conversion circuit is provided. The DC-DC voltage conversion circuit includes the drive circuit described in the first aspect.

[0017] According to a third aspect of the present invention, a DC-DC voltage conversion system is provided. The DC-DC voltage conversion system includes a DC-DC voltage conversion circuit as described in the second aspect and a switching power supply circuit.

[0018] In the embodiment of the present invention, since the voltage drop between the pull-up gate drive voltage and the source bias voltage is small after the pull-up, the voltage sampling module samples the drain voltage of the first switch when the second switch is turned on, which reduces the requirement for the gate-source voltage range of the second switch. That is, given the gate-source voltage range of the second switch, a larger gate-source voltage selection range is provided for the first switch. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0020] Figure 1 Here is a schematic circuit diagram of an example DC-DC system.

[0021] Figure 2 According to Figure 1 A schematic circuit diagram of the drive circuit for an example DC-DC system.

[0022] Figure 3 This is a structural block diagram of a driving circuit according to an embodiment of the present invention.

[0023] Figure 4 According to Figure 3 A schematic circuit diagram of the driving circuit in the embodiment. Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and thoroughly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art should fall within the protection scope of the present invention.

[0025] The specific implementation of the embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0026] Figure 1 This is a schematic circuit diagram of a DC voltage conversion system based on an example. Figure 1 The illustrated DC-DC conversion system 100 includes a DC-DC conversion circuit 110 (DC-DC chip) and a switching power supply circuit composed of an inductor L, a resistor RL, a capacitor C, etc. The DC-DC circuit 110 converts the DC input voltage VIN to DC by controlling the on / off state of the switching transistor installed therein, obtaining a DC output voltage VOUT across the capacitor C. This DC-DC system can be applied to power DC-consuming equipment; for example, it can be used as a DC adapter for electronic devices. The DC-DC system can also be integrated into a power management system as a power supply unit for microcontrollers such as MCUs.

[0027] Specifically, the DC-DC circuit 110 includes a control circuit 120 and a drive circuit 130. The switching transistor can be located within the drive circuit 130 or independently within the DC-DC circuit 110. The DC input voltage VIN can serve as a common power supply voltage for both the control circuit 120 and the drive circuit 130. The connection point between the DC-DC circuit 110 and the inductor L is the OUT terminal of the drive circuit 130, for example, the drain of the switching transistor. The drive circuit 130 may also include a voltage sampling terminal CS, which is connected to the control circuit 120 and used to provide feedback on the sampled gate-drain voltage of the switching transistor.

[0028] The control circuit 120 generates a PWM (Pulse Width Modulation) control signal, which carries a high or low level to drive the drive circuit 130.

[0029] The following further combines Figure 2 Detailed description Figure 1 An example circuit topology for at least a portion of the drive circuitry 130. In this example, the P-type MOS switch is labeled PM, and the N-type MOS switch is labeled NM.

[0030] like Figure 2 As shown, the gates of PM24 and PM20 are connected to the source of PM22. That is, the gate of PM22 outputs the gate drive voltage required by PM24 and PM20 from the source through the control of S1 and S2. The switching transistor PM20 can be an integrated switching transistor used to connect to the switching power supply circuit. PM24 is used to sample the gate-drain voltage of PM20.

[0031] Specifically, control circuit 120 generates signals S1 and S2. When the voltage of S1 is approximately VIN and S2 indicates a logic high level, the voltage of S1 pulls up the gate-source voltage of PM23, turning off PM23. In PM26 to PM2n (n-6 PM switches), the gate and drain of each PM are connected. The models of the PMs in PM26 to PM2n can be the same or different. The gate-drain voltage drop of each PM is equal to the gate-source voltage. The gate-source voltages of each PM can be the same or different. In one example, it is assumed that the gate-source voltage of each PM is VGS.

[0032] When the logic high level of S2 controls NM20 to turn off, the current flowing through PM26 to PM2n is the current of the constant current source I21. The gate voltage of PM22 is pulled low to VIN-(n-6)*VGS. Correspondingly, the gate voltages of PM20 and PM24 are VIN-(N-6)*VGS+VGS2, where VGS2 is the gate-source voltage of PM22.

[0033] When the voltage of S1 is low and the logic level of S2 is low, the gate voltage of PM22 is pulled high. Specifically, the logic-low level of S2 turns off NM0, causing the gate voltage of PM22 to be pulled up to VIN by transistors PM26 to PM2n. Furthermore, transistor PM23 is turned on, and the pull-up current value of PM22 is the same as that of the constant current source I22, causing the gate voltage of PM22 to be pulled up to VIN through PM23.

[0034] In addition, resistor R21 can provide pull-up current for PM2, ensuring that the gate voltage of PM22 is pulled up to VIN when the DC-DC circuit 110 is not working, thereby turning off the PM22 transistor.

[0035] In addition, R22 can be connected between the drain of the PM22 tube and ground to prevent uncontrollable latch-up effects from occurring in the PM22.

[0036] It should be understood that the above example is only one specific example of providing the gate voltage of PM22, and other voltage generation modules or voltage generation circuits are also used to generate the gate voltage of PM22.

[0037] The changes in the switching power supply circuit when the gate voltage of PM22 is pulled down and pulled up are discussed below.

[0038] When the gate voltage of PM22 is pulled low, the gate drive voltages of PM24 and PM20, the source outputs of PM22, are also low (e.g., the gate-source voltage is at a logic low level). The gate drive voltage of PM20 turns PM20 on, and correspondingly, in the switching power supply circuit, VIN is connected to the OUT terminal through PM20. Simultaneously, to accurately calculate the DC voltage of VOUT, it is necessary to calculate the voltage drop formed by the gate-drain voltage of PM20 in the switching power supply circuit. When the gate drive voltage of PM24 is low (e.g., the gate-source voltage is at a logic low level), PM24 turns on. Through R25 connected between the drain of PM20 and VIN, the drain voltage of PM20 corresponding to the voltage sampling terminal CS can be determined.

[0039] Furthermore, when the gate voltage of PM22 is pulled high, the gate drive voltages of the source outputs PM24 and PM20 are also high (e.g., the gate-source voltage is at a logic high level). The gate drive voltage of PM20 causes PM20 to turn off, and correspondingly, in the switching power supply circuit, the OUT terminal is disconnected from VIN. Simultaneously, when the gate drive voltage of PM24 is high (e.g., the gate-source voltage is at a logic high level), PM24 turns off. The source voltage of PM20 can be determined through the voltage sampling terminal CS.

[0040] Therefore, through the configuration of the above driving circuit, the gate of PM22, controlled by S1 and S2, can flexibly output the gate drive voltages required by PM24 and PM20 from the source of PM22. To improve the performance of the switching transistor PM20, a larger gate drive voltage can be used, for example, by implementing PM20 as a discrete switching transistor. If the above driving circuit generates a larger gate drive voltage, the gate-source voltages of other MOSFETs in the driving circuit may exceed their tolerance range.

[0041] To this end, embodiments of the present invention provide a series of technical solutions that offer a wider range of gate-source voltage selection for switching transistors.

[0042] Figure 3 This is a structural block diagram of a driving circuit according to an embodiment of the present invention. Figure 3 The driving circuit is used to drive the first switching transistor disposed in the switching power supply circuit. The driving circuit 130 in this embodiment is suitable for... Figure 1 The DC-DC system includes a driving circuit 130 comprising a voltage generation module 310, a voltage pull-up module 320, and a voltage sampling module 330.

[0043] The voltage generation module 310 is used to generate the source bias voltage of the first switch and the gate drive voltage of the first switch, which is used to turn on the first switch.

[0044] The voltage pull-up module 320 is connected to the voltage generation module 310 and is used to pull up the gate drive voltage and output the pull-up gate drive voltage.

[0045] The voltage sampling module 330 includes a second switch transistor. The gate of the second switch transistor is connected to the pull-up gate drive voltage, and the source of the second switch transistor is connected to the source bias voltage. The voltage sampling module samples the drain voltage of the first switch transistor when the second switch transistor is turned on.

[0046] In the embodiment of the present invention, since the voltage drop between the pull-up gate drive voltage and the source bias voltage is small after the pull-up, the voltage sampling module samples the drain voltage of the first switch when the second switch is turned on, which reduces the requirement for the gate-source voltage range of the second switch. That is, given the gate-source voltage range of the second switch, a larger gate-source voltage selection range is provided for the first switch.

[0047] It should also be understood that the first switching transistor in the embodiments of the present invention can be disposed in the driving circuit as part of the driving circuit. Alternatively, the first switching transistor may not be disposed in the driving circuit, but may be disposed as a discrete device or disposed in the switching power supply circuit.

[0048] Figure 4 According to Figure 3 A schematic circuit diagram of the driving circuit in the embodiment. It should be understood that... Figure 4 Schematic circuit diagram and Figure 2 The schematic circuit diagram corresponds to some of the components, among which, Figure 4 PM30 and Figure 2 PM20 corresponds to, and Figure 2 Unlike other components, the PM30 can be included in the drive circuit or not. It should also be understood that... Figure 4 In the example, PM30 is not part of the voltage sampling module; in other examples, PM30 may be included as part of the voltage sampling module in the drive circuit. PM26-PM2n corresponds to PM36-PM3n, NM20 corresponds to NM30, I21 and I22 correspond to I31 and I32 respectively, PM23 and PM22 correspond to PM33 and PM32 respectively, and R21 and R22 correspond to R31 and R32 respectively. Figure 4 The functions and connections of the above-mentioned components can be found in the reference section. Figure 2 This will not be elaborated upon here.

[0049] As at least part Figure 3 An example of a driving circuit, in Figure 4In the circuit diagram, the source of PM32 outputs the gate drive voltage before the pull-up gate drive voltage. That is, the gate drive voltage is not directly input to PM31 (an example of the second switch) for sampling, but is instead input to the gate of PM31 (e.g., an example of the second switch) in the voltage sampling module 330. Correspondingly, voltage sampling is performed from the connection between the source of PM31 and R36 (an example of the second resistor). Generally, the voltage sampling module includes a second resistor, with the source of the second switch connected to one end of the second resistor and the sampling terminal. The other end of the second resistor is connected to the source bias voltage, and the drain of the second switch is connected to the drain of the first switch. This simplifies the circuit configuration of the voltage sampling module within a given gate-source voltage range for the second switch.

[0050] Furthermore, when the source voltage of PM32 is pulled low, the gate voltage of PM34 in the voltage pull-up module 320 is also pulled low, causing PM34 to conduct. In the branch where PM34 is located, R33 (an example of the fifth resistor), R34 (an example of the fourth resistor), and R35 (an example of the third resistor) are connected in series. Based on the voltage division relationship formed by R35 in the branch, the gate input voltage of PM31 connected between R35 and the source of PM34 is lower than VIN. By configuring the resistance values ​​of R33, R34, and R35, the gate input voltage of PM31 at this time can form the logic low level of PM31, thereby turning on PM31 and sampling the drain voltage of PM1 (i.e., the drain voltage of PM0) at the CS terminal.

[0051] When the source voltage of PM32 is pulled high, the gate voltage of PM34 in the voltage pull-up module 320 is also pulled high, causing PM34 to turn off. The gate input voltage of PM31, which is connected between R35 and the source of PM34, is pulled high to VIN, thereby turning off PM31. The source voltage of PM1 (i.e., the source voltage of PM0) is sampled at the CS terminal.

[0052] Without loss of generality, the voltage pull-up module 320 includes a third switch (e.g., PM34) and a third resistor. The gate of the third switch is connected to the gate drive voltage, one end of the third resistor is connected to the source bias voltage, and the other end of the third resistor is connected to the source of the third switch and the gate of the second switch. The drain of the third switch is grounded. Especially when the second and third switches are integrated switches, the existence of a voltage between the source and gate of the third switch enables the pull-up of the gate voltage of the second switch, further reducing the possibility that the gate-source voltage exceeds the tolerance range of the second switch. Furthermore, the third resistor effectively pulls down the gate voltage of the second switch, providing a sufficient voltage drop range for the switching control of the second switch.

[0053] In addition, the voltage pull-up module also includes a fourth resistor, which is connected in series between the third resistor and the source of the third switching transistor. By configuring the resistance values ​​of the fourth and third resistors, the gate input voltage of the second switching transistor can be accurately configured within the gate-source voltage range of the second switching transistor, thereby achieving accurate switching control of the second switching transistor.

[0054] Furthermore, the voltage pull-up module may include a first diode (e.g., D0). The cathode of the first diode is connected to the source bias voltage, and the anode of the first diode is connected between the source of the third switch and the third resistor. The first diode protects the gate-source voltage of the second switch from exceeding its withstand voltage. For example, D0 with a breakdown voltage of 5V can be selected, and the voltage drop across the third resistor can be configured to exceed 5V. Thus, the gate-source voltage of the second switch is regulated by D0.

[0055] In addition, the voltage pull-up module 320 includes a fifth resistor (e.g., R33), one end of which is connected to the drain of the third switching transistor, and the other end of which is grounded to prevent uncontrollable latch-up effects from occurring in PM34.

[0056] For voltage generation module 310, it can be used with Figure 2 circuit Figure 1 In some examples, voltage generation module 310 includes a fourth switch (e.g., PM33) and a fifth switch (e.g., PM32). The source of the fourth switch is connected to a source bias voltage, the drain of the fourth switch is connected to the source of the fifth switch, the drain of the fifth switch is grounded, and the gate of the third switch is connected to the drain of the fourth switch and the source of the fifth switch. The gate of the fourth switch receives a first control voltage (e.g., S1) and turns on according to the first control voltage, while the gate of the fifth switch turns on according to a second control voltage (e.g., S2). In voltage generation module 310, flexible control of the gate drive voltage of the first switch is achieved through the first control voltage and the second control voltage. It should be understood that the first control voltage and the second control voltage can be generated by control circuitry 120.

[0057] In addition, the fifth, third, and second switching transistors can all be integrated into a single driving circuit.

[0058] In addition, the second constant current source I32 can be connected in series between the source of the fourth switch and the source bias voltage, so as to effectively pull up the voltage of the drain of the fourth switch (i.e., the gate of the third switch) when the third switch is turned off.

[0059] In addition, the voltage generation module 310 may also include a first resistor (e.g., R31) connected between the source bias voltage and the gate of the fifth switch. Through the first resistor, when the S2 indicates a low logic level, the source voltage of the fifth switch can be quickly pulled up to VIN via R31, so that the fifth switch can be quickly turned off.

[0060] Additionally, the voltage generation module 310 may also include a second diode (e.g., D31) and a third diode (e.g., D32), with the anode of the second diode connected to the anode of the third diode, the cathode of the second diode connected to the source of the fifth switching transistor, and the cathode of the third diode connected to the gate of the fifth switching transistor. By configuring the second and third diodes, the gate-source voltage of the fifth switching transistor is effectively clamped, making the gate-source voltage of the fifth switching transistor more stable.

[0061] Furthermore, the voltage generation module also includes a sixth switching transistor and a pull-down resistor. Figure 4 and Figure 2 In the example, the pull-down resistor is implemented by connecting several gate-drain switching transistors in series. However, this is only an example. It can also be implemented by an equivalent device with a preset pull-down resistance value, which is based on the second control voltage.

[0062] Additionally, a pull-down resistor is connected between the source of the sixth switch and its source bias voltage. The gate of the fifth switch is connected to the source of the sixth switch. The gate of the sixth switch receives a second control voltage and is turned on according to the second control voltage. By using the pull-down resistor and the gate-source voltage of the fifth switch, the gate drive voltage of the first switch is flexibly output.

[0063] The voltage generation module 310 may also include a first constant current source I31. When the logic high level of S2 controls NM30 to turn off, the current flowing through PM36 to PM3n is the current of the first constant current source I31. The gate voltage of PM32 is pulled down to VIN-(n-6)*VGS. Correspondingly, the gate voltages of PM30 and PM34 are VIN-(N-6)*VGS+VGS2, where VGS2 is the gate-source voltage of PM32.

[0064] Correspondingly, as PM32 is turned on, PM34 is also turned on, and its source voltage is VIN-(N-6)*VGS+VGS2+VGS4, where VGS4 is the gate-source voltage of PM4.

[0065] Accordingly, as PM32 is turned on, the gate voltage of PM31 is VIN-VR5, where VR5 is the voltage drop across R35.

[0066] In the embodiments of the present invention, for example, the upper limit of the gate-source voltage of the integrated switching transistor can be 6V, that is, the gate-source voltage of the first switching transistor can exceed 6V, and the gate-source voltage of all integrated switching transistors other than the first switching transistor cannot exceed 6V.

[0067] Those skilled in the art will recognize that the units and method steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of the embodiments of the present invention.

[0068] The above embodiments are only used to illustrate the embodiments of the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of the present invention. Therefore, all equivalent technical solutions also fall within the scope of the embodiments of the present invention, and the patent protection scope of the embodiments of the present invention should be defined by the claims.

Claims

1. A driving circuit for driving a first switching transistor disposed in a switching power supply circuit, the driving circuit comprising: A voltage generation module is used to generate a source bias voltage for the first switch and a gate drive voltage for the first switch, wherein the gate drive voltage is used to turn on the first switch. A voltage pull-up module, connected to the voltage generation module, is used to pull up the gate drive voltage and output a pull-up gate drive voltage; A voltage sampling module includes a second switch transistor, the gate of which is connected to the pull-up gate drive voltage, and the source of which is connected to the source bias voltage. The voltage sampling module samples the drain voltage of the first switch transistor when the second switch transistor is turned on. The voltage sampling module further includes a second resistor, the source of the second switching transistor is connected to one end of the second resistor and the sampling terminal, the other end of the second resistor is connected to the source bias voltage, and the drain of the second switching transistor is connected to the drain of the first switching transistor. The voltage pull-up module includes a third switch and a third resistor. The gate of the third switch is connected to the gate drive voltage. One end of the third resistor is connected to the source bias voltage. The other end of the third resistor is connected to the source of the third switch and the gate of the second switch. The drain of the third switch is grounded. The voltage pull-up module also includes a fourth resistor, which is connected in series between the third resistor and the source of the third switching transistor; The voltage pull-up module also includes a fifth resistor, one end of which is connected to the drain of the third switching transistor, and the other end of which is grounded. The voltage pull-up module includes a first diode, the cathode of which is connected to the source bias voltage, and the anode of which is connected between the source of the third switch and the third resistor. The voltage generation module includes a fourth switch and a fifth switch. The source of the fourth switch is connected to the source bias voltage, the drain of the fourth switch is connected to the source of the fifth switch, the drain of the fifth switch is grounded, and the gate of the third switch is connected to the drain of the fourth switch and the source of the fifth switch. The gate of the fourth switch receives a first control voltage and is turned on according to the first control voltage; the gate of the fifth switch receives a second control voltage and is turned on according to the second control voltage. The voltage generation module further includes a sixth switch and a pull-down resistor. The pull-down resistor is connected between the source of the sixth switch and the source bias voltage. The gate of the fifth switch is connected to the source of the sixth switch. The gate of the sixth switch receives a second control voltage and is turned on according to the second control voltage. The voltage generation module further includes a first resistor connected between the source bias voltage and the gate of the fifth switching transistor.

2. A DC voltage conversion circuit, comprising: The driving circuit according to claim 1.

3. A DC voltage conversion system, comprising: The DC voltage conversion circuit and the switching power supply circuit according to claim 2.

Images