Crosstalk suppression circuit, MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) driving circuit and bridge type functional circuit

Abstract

The utility model discloses a crosstalk suppression circuit, an MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) driving circuit and a bridge type functional circuit, and relates to the field of power electronic device control. The output end of a driving chip is respectively connected with the grid electrode of an MOSFET corresponding to the MOSFET driving circuit and the first end of a controllable switch module through a driving resistor; the source electrode of the MOSFET is connected with the other end of the bleeder resistor, one end of the clamping matching resistor and the cathode of the first voltage stabilizing diode, the other end of the clamping matching resistor is connected with the power supply end of the driving chip, and the grounding end of the driving chip, the anode of the first voltage stabilizing diode and the control end of the controllable switch module are connected and then grounded. The first capacitor is connected in parallel with the driving resistor, and the first capacitor can discharge to realize suppression when forward crosstalk occurs; when negative crosstalk occurs, the controllable switch module is switched on to realize negative crosstalk suppression; according to the scheme, a path of control signal cost does not need to be additionally introduced, and reliable operation of the MOSFET under high switching frequency is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of power electronic device control, in particular to a crosstalk suppression circuit, a MOSFET drive circuit and a bridge function circuit. Background Art

[0002] MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) has the advantages of high frequency, high efficiency, high voltage resistance and high power density. Its application has become mainstream in the current power electronics industry. However, these characteristics also bring new problems. The pulse voltage and pulse current caused by high-speed switching action have a significant interference with the gate-source voltage of MOSFET. This interference is called crosstalk.

[0003] Currently, there are two main methods for suppressing MOSFET driver crosstalk: passive crosstalk suppression and active crosstalk suppression. However, the passive crosstalk suppression scheme cannot effectively suppress negative crosstalk, and the active crosstalk suppression scheme requires adding a MOSFET internally and requiring the driver chip to provide a separate IO output port to connect to the control port of the MOSFET. For driver chips with limited output ports, this adds a control signal cost, which is not conducive to practical applications.

[0004] Therefore, how to provide an effective crosstalk suppression circuit to effectively suppress positive crosstalk and negative crosstalk is a problem that needs to be solved urgently. Utility Model Content

[0005] In view of this, the utility model provides a crosstalk suppression circuit, a MOSFET drive circuit and a bridge function circuit, which do not require the cost of introducing an additional control signal, and can effectively suppress positive crosstalk and negative crosstalk, ensuring that the MOSFET operates reliably at high switching frequencies.

[0006] To solve the above technical problems, the present application provides a crosstalk suppression circuit, which is applied to a MOSFET driving circuit in a bridge functional circuit. The bridge functional circuit includes multiple groups of bridge arms. A corresponding MOSFET driving circuit is provided for the MOSFET located in the upper bridge arm and the MOSFET located in the lower bridge arm in any group of bridge arms; the MOSFET driving circuit includes a driving resistor, a clamping matching resistor, and a first voltage regulator diode; the crosstalk suppression circuit includes a first capacitor, a controllable switch module, and a bleeder resistor;

[0007] The output end of the driving chip in the bridge function circuit is connected with the gate of the corresponding MOSFET of the MOSFET driving circuit and the first end of the controllable switch module through the driving resistor.

[0008] The source of the MOSFET is connected with the other end of the discharge resistor, one end of the clamping auxiliary resistor and the cathode of the first voltage stabilizing diode, respectively.

[0009] The first capacitor is connected with the driving resistor in parallel, and the capacitance of the first capacitor is greater than that of the gate-source parasitic capacitance of the corresponding MOSFET.

[0010] The controllable switch module is used to turn on when the gate-source parasitic capacitance of the corresponding MOSFET is discharged through the driving resistor, otherwise, it remains off.

[0011] Further, the driving resistor includes a first driving resistor, a second driving resistor and a third driving resistor.

[0012] One end of the first driving resistor is connected with the output positive end of the driving chip, and the other end of the first driving resistor is connected with one end of the second driving resistor, one end of the third driving resistor and one end of the first capacitor, respectively.

[0013] The other end of the third driving resistor is connected with the output negative end of the driving chip.

[0014] Further, it further includes a voltage dividing resistor.

[0015] One end of the voltage dividing resistor is connected with the gate of the corresponding MOSFET, and the other end is connected with the source of the MOSFET.

[0016] Further, it further includes a second voltage stabilizing diode and a third voltage stabilizing diode.

[0017] The anode of the second voltage stabilizing diode is connected with the anode of the third voltage stabilizing diode, the cathode of the second voltage stabilizing diode is connected with the gate of the corresponding MOSFET, and the cathode of the third voltage stabilizing diode is connected with the source of the MOSFET.

[0018] Further, it further includes a clamping capacitor connected with the first voltage stabilizing diode in parallel.

[0019] Further, the controllable switch module comprises a controllable switch and a protection resistor;

[0020] The control end of the controllable switch is connected with one end of the protection resistor, the other end of the protection resistor is used as the control end of the controllable switch module, the first end of the controllable switch is used as the first end of the controllable switch module, and the second end of the controllable switch is used as the second end of the controllable switch module.

[0021] Further, the controllable switch module further comprises a diode;

[0022] The anode of the diode is connected with the first end of the controllable switch, and the cathode of the diode is used as the first end of the controllable switch module.

[0023] Further, the controllable switch is an NPN type triode.

[0024] To solve the above technical problems, the utility model further provides a MOSFET drive circuit, including drive resistance, clamping supporting resistance and first stabilizing diode, still include the crosstalk suppression circuit as above-mentioned;

[0025] The crosstalk suppression circuit is connected with the drive resistance, the clamping supporting resistance and the first stabilizing diode respectively.

[0026] To solve the above technical problems, the utility model further provides a bridge function circuit, including multiple groups of bridge arms, each group of bridge arms includes the first MOSFET in the upper bridge arm and the second MOSFET in the lower bridge arm;

[0027] The bridge function circuit further comprises the MOSFET drive circuit as described above, the first MOSFET is connected with the corresponding MOSFET drive circuit for driving the first MOSFET, and the second MOSFET is connected with the corresponding MOSFET drive circuit for driving the second MOSFET.

[0028] The application provides a crosstalk suppression circuit, a MOSFET driving circuit and a bridge function circuit, the crosstalk suppression circuit comprises a first capacitor, a controllable switch module and a discharge resistor, the output end of a driving chip is connected with the gate of a corresponding MOSFET of the MOSFET driving circuit and the first end of the controllable switch module through a driving resistor, the second end of the controllable switch module is connected with one end of the discharge resistor, the source of the MOSFET is connected with the other end of the discharge resistor, one end of a clamping auxiliary resistor and the cathode of a first voltage stabilizing diode, the other end of the clamping auxiliary resistor is connected with the power supply end of the driving chip, the grounding end of the driving chip, the anode of the first voltage stabilizing diode and the control end of the controllable switch module are connected and the common end is grounded, the first capacitor is connected with the driving resistor in parallel and the capacitance value is greater than the capacitance value of the gate-source parasitic capacitance of the corresponding MOSFET, then the first capacitor can discharge to generate a voltage with a direction opposite to the voltage generated by the positive crosstalk on the gate-source parasitic capacitance of the corresponding MOSFET to weaken or even eliminate the influence of the positive crosstalk, so that the positive crosstalk suppression is realized; when the negative crosstalk occurs, the gate-source parasitic capacitance of the corresponding MOSFET discharges through the driving resistor to make the controllable switch module conduct, at this time, the current of the negative crosstalk is discharged through the controllable switch module and the discharge resistor, so that the negative crosstalk suppression is realized, it can be seen that the scheme does not need to introduce an additional control signal, can well suppress the positive crosstalk and the negative crosstalk, is more beneficial to practical application, ensures the reliable operation of the MOSFET under high switching frequency and is beneficial to improving the safety and reliability of the entire bridge function circuit.

[0029] The above description is only a summary of the technical scheme of the application, in order to more clearly understand the technical means of the application, the specific embodiments of the application can be implemented according to the content of the description, and in order to make the above and other purposes, characteristics and advantages of the application more obvious and easy to understand, the following specifically describes the specific embodiments of the application. BRIEF DESCRIPTION OF DRAWINGS

[0030] The drawings described herein are used to provide further understanding of the application, constitute a part of the application, the schematic embodiments of the application and the description thereof are used to explain the application and do not constitute an improper limitation on the application. In the drawings:

[0031] Figure 1 A structure schematic view of the crosstalk suppression circuit provided by the application;

[0032] Figure 2 A crosstalk occurrence schematic view of the MOSFET located in the upper bridge arm and the MOSFET located in the lower bridge arm when a group of bridge arms are taken as an example provided by the application. DETAILED DESCRIPTION

[0033] The utility model discloses a core provides a kind of crosstalk suppression circuit, MOSFET drive circuit and bridge function circuit, without extra introduction one-way control signal cost, and can be well inhibited positive crosstalk and negative crosstalk, ensure MOSFET reliable operation under high switching frequency.

[0034] The technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present application.

[0035] The terms "first", "second" and the like in the specification and claims of the present application are used to distinguish similar objects, not to describe a particular order or chronological sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second" and the like are generally of a kind, not limited to the number of objects, for example, the first object can be one or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / ", generally indicates that the front and rear associated objects are in a "or" relationship.

[0036] Please refer to Figure 1 , Figure 1 The structure schematic diagram of a crosstalk suppression circuit provided by the present application.

[0037] The crosstalk suppression circuit is applied to the MOSFET drive circuit in the bridge function circuit, the bridge function circuit includes multiple bridge arms, and the MOSFET drive circuit corresponding to the MOSFET located in the upper bridge arm and the MOSFET located in the lower bridge arm in any one bridge arm is provided; the MOSFET drive circuit includes a drive resistor, a clamping matching resistor and a first stabilizing diode; the crosstalk suppression circuit includes a first capacitor, a controllable switch module and a discharge resistor;

[0038] The output end of the drive chip in the bridge function circuit is connected with the gate of the corresponding MOSFET of the MOSFET drive circuit and the first end of the controllable switch module through the drive resistor, and the second end of the controllable switch module is connected with one end of the discharge resistor;

[0039] The source of the MOSFET is connected with the other end of the discharge resistor, one end of the clamping matching resistor and the cathode of the first stabilizing diode, respectively, the other end of the clamping matching resistor is connected with the power supply end of the drive chip, and the ground end of the drive chip, the anode of the first stabilizing diode and the control end of the controllable switch module are connected and the common end is grounded;

[0040] The first capacitor is connected in parallel with the driving resistor, and the capacitance of the first capacitor is greater than the capacitance of the gate-source parasitic capacitor of the corresponding MOSFET.

[0041] The controllable switch module is used to turn on when the gate-source parasitic capacitor of the corresponding MOSFET is discharged through the driving resistor; otherwise, the controllable switch module is kept off.

[0042] In the embodiment, the MOSFETs herein include but are not limited to silicon carbide MOSFETs; the bridge functional circuit herein can be various circuits that utilize MOSFETs and realize various specific functions such as inversion based on a bridge structure, such as a three-phase full-bridge inverter circuit. More specifically, the bridge functional circuit includes multiple bridge arms, each bridge arm includes two MOSFETs arranged in an upper and lower manner, and each MOSFET is provided with a corresponding MOSFET driving circuit in a matched manner, and the crosstalk suppression circuit is applied to each MOSFET driving circuit.

[0043] Please refer to Figure 2 , Figure 2 The MOSFET located at the upper bridge arm and the MOSFET located at the lower bridge arm are taken as an example, wherein the MOSFET located at the upper bridge arm is referred to as an upper MOSH, the MOSFET located at the lower bridge arm is referred to as a lower MOSL, Vgs represents the voltage across the gate-source parasitic capacitor of the corresponding MOSFET, and Vds represents the voltage across the drain-source parasitic capacitor of the corresponding MOSFET. The first curve 11 from top to bottom shows a variation diagram of Vds of the lower MOSL, the second curve 12 shows a variation diagram of Vgs of the lower MOSL, and the third curve 13 shows a variation diagram of Vgs of the upper MOSH. It can be seen that the positive crosstalk essentially occurs in the following case: in the same bridge arm, one MOSFET is in a steady-state off state and the other MOSFET is in a Miller platform during a conduction process, and at this time, the MOSFET in the off state has positive crosstalk. The negative crosstalk essentially occurs in the following case: in the same bridge arm, one MOSFET is in a steady-state off state or before being turned on, and the other MOSFET is in a Miller platform during a conduction process, and at this time, the MOSFET in the off state has negative crosstalk.

[0044] From the implementation principle, the first capacitor will complete the charging and energy storage process when its corresponding MOSFET (the correspondence here means that, for example, the current first capacitor is used to drive the MOSFET driving circuit located in the upper bridge arm MOSFET, then the first capacitor corresponds to the upper bridge arm MOSFET) is in the steady-state conduction process to reach the initial voltage; then, when the corresponding MOSFET has positive crosstalk, the positive crosstalk will generate a positive voltage at the top and a negative voltage at the bottom at both ends of the gate-source parasitic capacitance of the MOSFET. Since the first capacitor is fully charged and the capacitance of the first capacitor is greater than the capacitance of the gate-source parasitic capacitance, the first capacitor will start to discharge and generate a negative voltage at the top and a positive voltage at the bottom at both ends of the gate-source parasitic capacitance, thereby weakening or even eliminating the impact of the forward crosstalk. During this process, the controllable switch module remains turned off.

[0045] When negative crosstalk occurs, the gate-source parasitic capacitance of the corresponding MOSFET is discharged through the driving resistor, and when the voltage between the control end and the first end of the controllable switch module is greater than the turn-on voltage of the controllable switch module itself, the controllable switch module is turned on. At this time, the current of the negative crosstalk is discharged through the controllable switch module and the discharge resistor, thereby achieving negative crosstalk suppression.

[0046] In addition, if Figure 1 As shown, a group of bridge arms are taken as an example for further schematic explanation. Similarly, the MOSFET located in the upper bridge arm is referred to as the upper tube MOSH, which includes the gate-source parasitic capacitance CgsH, the gate-drain parasitic capacitance CgdH and the drain-source parasitic capacitance CdsH; the MOSFET located in the lower bridge arm is referred to as the lower tube MOSL, which includes the gate-source parasitic capacitance CgsL, the gate-drain parasitic capacitance CgdL and the drain-source parasitic capacitance CdsL; the upper tube MOSH is provided with a MOSFET drive circuit DriveH, and the lower tube MOSL is provided with a MOSFET drive circuit DriveL, and here there is a driver chip for each MOSFET drive circuit, and the input positive terminal IN+ of the driver chip ICH of the upper tube MOSH passes through the current limiting resistor R 1H It is connected to the DSP control module to drive the upper tube MOSH to be turned on and off according to the control instructions of the DSP control module. The negative input terminal IN- of the driver chip ICH is grounded. The first power supply terminal VCC1 and the second power supply terminal VCC2 of the driver chip ICH are connected to the auxiliary power module PowerH for power supply. Similarly, the positive input terminal IN+ of the driver chip ICL of the lower tube MOSL is connected to the lower tube MOSL through the current limiting resistor R 1L It is connected to the DSP control module to drive the lower tube MOSL to be turned on and off according to the control instructions of the DSP control module. The negative input terminal IN- of the driver chip ICL is grounded. The first power supply terminal VCC1 and the second power supply terminal VCC2 of the driver chip ICL are connected to the auxiliary power module PowerL for power supply.

[0047] A drive resistor 1H is arranged in the MOSFET drive circuit DriveH for the upper MOSH, and a clamping matching resistor R 7H , and a first voltage stabilizing diode DZ 1H A crosstalk suppression circuit is included in the MOSFET drive circuit DriveH, and the crosstalk suppression circuit includes a first capacitor C 2H , a controllable switch module 2H, and a bleeder resistor R 5H A drive resistor 1L is arranged in the MOSFET drive circuit DriveL for the lower MOSL, and a clamping matching resistor R 7L , and a first voltage stabilizing diode DZ 1L A crosstalk suppression circuit is included in the MOSFET drive circuit DriveL, and the crosstalk suppression circuit includes a first capacitor C 2L , a controllable switch module 2L, and a bleeder resistor R 5L .

[0048] In summary, the application provides a crosstalk suppression circuit, which does not need to introduce an additional control signal at a cost, and can well suppress positive crosstalk and negative crosstalk, is more conducive to practical application, ensures reliable operation of the MOSFET at a high switching frequency, and is conducive to improving the safety and reliability of the entire bridge function circuit.

[0049] On the basis of the above embodiment:

[0050] In some embodiments, the drive resistor includes a first drive resistor, a second drive resistor, and a third drive resistor;

[0051] One end of the first drive resistor is connected to the output positive end of the drive chip, the other end of the first drive resistor is connected to one end of the second drive resistor, one end of the third drive resistor, and one end of the first capacitor, respectively, the other end of the first capacitor is connected to the other end of the second drive resistor and the first end of the controllable switch module, respectively, and the common end of the connection is connected to the gate of the MOSFET;

[0052] The other end of the third drive resistor is connected to the output negative end of the drive chip.

[0053] It should be further noted that, as shown in Figure 1 For the MOSFET drive circuit DriveH for the upper MOSH, the drive resistor 1H includes a first drive resistor R 2H , a second drive resistor R gH , a third drive resistor R 3H , and a first capacitor C 2H is connected in parallel with the second drive resistor R gH For the MOSFET drive circuit DriveL for the lower MOSL, the drive resistor 1L includes a first drive resistor R2L , the second drive resistor R gL , the third drive resistor R 3L , the first capacitor C 2L is connected in parallel with the second drive resistor R gL .

[0054] In some embodiments, further comprising a voltage dividing resistor;

[0055] One end of the voltage dividing resistor is connected to the gate of the corresponding MOSFET, and the other end is connected to the source of the MOSFET.

[0056] In this embodiment, the voltage dividing resistor is used for voltage division to ensure the safe operation of the circuit. Specifically, as shown in Figure 1 , for the MOSFET drive circuit DriveH of the upper tube MOSH, a voltage dividing resistor R 4H is provided; and for the MOSFET drive circuit DriveL of the lower tube MOSL, a voltage dividing resistor R 4L is provided.

[0057] In some embodiments, further comprising a second zener diode and a third zener diode;

[0058] The anode of the second zener diode is connected to the anode of the third zener diode, the cathode of the second zener diode is connected to the gate of the corresponding MOSFET, and the cathode of the third zener diode is connected to the source of the MOSFET.

[0059] In this embodiment, the provision of the second zener diode and the third zener diode helps to further prevent the corresponding MOSFET from being broken down. Specifically, as shown in Figure 1 , for the MOSFET drive circuit DriveH of the upper tube MOSH, a second zener diode DZ 2H and a third zener diode DZ 3H are provided; and for the MOSFET drive circuit DriveL of the lower tube MOSL, a second zener diode DZ 2L and a third zener diode DZ 3L are provided.

[0060] In some embodiments, further comprising a clamping capacitor connected in parallel with the first zener diode.

[0061] In this embodiment, the provision of the clamping capacitor helps to better achieve clamping in cooperation with the first zener diode. Specifically, for the MOSFET drive circuit DriveH of the upper tube MOSH, a clamping capacitor C 1H is provided; and for the MOSFET drive circuit DriveL of the lower tube MOSL, a clamping capacitor C 1L is provided.

[0062] In some embodiments, the controllable switch module includes a controllable switch and a protection resistor;

[0063] The control end of the controllable switch is connected to one end of the protection resistor, the other end of the protection resistor serves as the control end of the controllable switch module, the first end of the controllable switch serves as the first end of the controllable switch module, and the second end of the controllable switch serves as the second end of the controllable switch module.

[0064] In this embodiment, the above configuration can realize the functions of the controllable switch module simply, reliably and safely. Figure 1 As shown, for the MOSFET drive circuit DriveH of the upper tube MOSH, a protection resistor R 6H ; For the MOSFET drive circuit DriveL of the lower tube MOSL, it is equipped with a protection resistor R 6L .

[0065] In some embodiments, the controllable switch module further includes a diode;

[0066] The anode of the diode is connected to the first end of the controllable switch, and the cathode of the diode serves as the first end of the controllable switch module.

[0067] In this embodiment, the above configuration can be used to prevent current from being reversed. Specifically, Figure 1 As shown, for the MOSFET drive circuit DriveH of the upper tube MOSH, it is provided with a diode D 1H ; For the MOSFET drive circuit DriveL of the lower tube MOSL, it is provided with a diode D 1L .

[0068] In some embodiments, the controllable switch is an NPN transistor.

[0069] Specifically, considering that NPN transistors have the advantages of low cost, high stability and easy debugging, NPN transistors can be used as controllable switches. Specifically, Figure 1 As shown, for the MOSFET drive circuit DriveH of the upper tube MOSH, it is provided with an NPN transistor T 1H ; For the MOSFET drive circuit DriveL of the lower tube MOSL, it is provided with an NPN transistor T 1L .

[0070] The following combination Figure 1 and Figure 2 , gives a complete description of the principle of the crosstalk suppression circuit provided by the utility model:

[0071] At 0-t1, it is a steady state, at this time, the lower tube MOSL is turned on, the upper tube MOSH is turned off, and the driving chip ICL continuously charges the loop, so that the first capacitor C 2L reaches the initial voltage (the charging energy of the first capacitor C 2H is not described here), the voltage direction of the first capacitor C 2L is left positive and right negative, and the voltage value is the voltage division of the second driving resistor R gL and the voltage division resistor R 4L ; the positive forward crosstalk occurs at t1-t4, when the lower tube MOSL is turned off, the output voltage of the driving chip ICL is 0V, and the first voltage stabilizing diode DZ 1L stabilizes the source of the lower tube MOSL to a certain positive voltage, at this time, the lower tube MOSL is turned off under negative voltage, the diode D 1L is turned off under negative voltage, and the NPN triode T 1L is turned off; when the upper tube MOSH is turned on, the output voltage of the driving chip ICH is VCC, the diode D 1L is turned off under negative voltage, and the NPN triode T 1L is turned off. Without positive forward crosstalk, the driving signals of the lower tube MOSL and the upper tube MOSH have no effect, the gate-source parasitic capacitor CgsL of the lower tube MOSL bears the negative voltage of the first voltage stabilizing diode DZ 1L , and the lower tube MOSL can be stably turned off. When there is positive forward crosstalk, at t3-t4, i.e. the Miller platform stage, the Vds of the upper tube MOSH rapidly decreases, and the Vds of the lower tube MOSL rapidly increases, at this time, an induced current is generated in the lower tube MOSL, which flows from top to bottom through the gate-source parasitic capacitor CgsL of the lower tube MOSL, and a voltage with upper positive and lower negative is generated on the gate-source parasitic capacitor CgsL of the lower tube MOSL, which, when superimposed with the gate-source voltage Vgs of the lower tube MOSL, causes the Vgs to rise. Since the turn-on threshold of MOSFET is very low, it can cause the lower tube MOSL to be mistakenly turned on and thus cause short circuit. However, through the scheme in the present application, the second driving resistor R gL is connected in parallel with the first capacitor C 2L , and the first capacitor C 2L already has a stable left positive and right negative voltage at 0-t1, and since its capacitance value is much larger than that of the gate-source parasitic capacitor CgsL of the lower tube MOSL, the voltage across the first capacitor C 2L is approximately constant during the turn-off process of the lower tube MOSL, so that when positive forward crosstalk occurs, the first capacitor C 2L begins to discharge, and the current on the gate-source parasitic capacitor CgsL of the lower tube MOSL flows from bottom to top, i.e. a voltage with lower positive and upper negative is generated on the gate-source parasitic capacitor CgsL of the lower tube MOSL, which is opposite to the voltage direction generated by the positive forward crosstalk, thereby achieving positive forward crosstalk suppression, and the controllable switch module remains off during the positive forward crosstalk suppression process.

[0072] At t5-t6, the steady state is reached. At this time, the lower tube MOSL is stably turned off, the upper tube MOSH is stably turned on, and the driver chip ICH continuously charges the circuit, making the first capacitor C 2H The negative crosstalk occurs at t6-t10. When the shutdown signal of the upper tube MOSH is issued, the output voltage of the driver chip ICH will be 0V. 1H The source of the upper MOSH is stabilized to a certain positive voltage. At this time, the upper MOSH has to withstand the negative voltage to turn off. The diode D 1H Withstand negative voltage shutdown, NPN transistor T 1L When the ON signal of the lower tube MOSL is sent, the output voltage of the driver chip ICL is VCC, and the diode D 1L Withstand negative voltage shutdown, NPN transistor T 1L When there is no negative crosstalk, the driving signals of the lower tube MOSL and the upper tube MOSH are not affected, and the gate-source parasitic capacitance CgsH of the upper tube MOSH withstands the first voltage regulator diode DZ 1H The negative voltage of the upper tube MOSH is stably turned off; the lower tube MOSL is stably transformed from negative voltage shutdown to positive voltage opening. When there is negative crosstalk, at t7-t8, that is, the Miller platform stage, the Vds of the lower tube MOSL drops rapidly, and the Vds of the upper tube MOSH rises rapidly. At this time, an induced current will be generated in the lower tube MOSL. This current will flow from bottom to top through the gate-source parasitic capacitance CgsL of the lower tube MOSL, and a negative upper and positive lower voltage will be generated on the gate-source parasitic capacitance CgsL of the lower tube MOSL. When it is superimposed with the Vgs of the lower tube MOSL, its Vgs value will be more negative, thereby reducing the gate-source drive voltage VgsL of the lower tube MOSL, which may cause VgsL to exceed the negative voltage peak. In severe cases, it will exceed the withstand voltage range of the lower tube and cause negative voltage breakdown. However, through the solution in this application, at t7-t8, when the lower tube MOSL is still in the off state, when the gate-source parasitic capacitance CgsL of the lower tube MOSL is discharged, it will be generated in the third drive resistor R 3L The left positive and right negative voltages are formed on the NPN transistor T 1L When the voltage between the base and emitter of the NPN transistor T is higher than its turn-on voltage 1L The diode D is turned on and 1L is turned on, the current will flow through the bleeder resistor R 5L Quickly discharge it to achieve negative crosstalk suppression.

[0073] The utility model also provides a MOSFET driving circuit, including a driving resistor, a clamping matching resistor and a first voltage stabilizing diode, and also includes the crosstalk suppression circuit as described above;

[0074] The crosstalk suppression circuit is connected with the driving resistor, the clamping matching resistor and the first voltage stabilizing diode respectively.

[0075] For the MOSFET driving circuit provided in the present application, please refer to the above-mentioned embodiments of the crosstalk suppression circuit, and Figure 1 The MOSFET driving circuit has been illustrated in the above-mentioned embodiments, and thus will not be described here.

[0076] The utility model discloses still provide a kind of bridge function circuit, including multiple groups of bridge arms, each group of bridge arms includes the first MOSFET in upper bridge arm and the second MOSFET in lower bridge arm;

[0077] The bridge function circuit further includes the MOSFET driving circuit as described above, the first MOSFET is connected with the corresponding MOSFET driving circuit for driving the first MOSFET, and the second MOSFET is connected with the corresponding MOSFET driving circuit for driving the second MOSFET.

[0078] For the MOSFET driving circuit provided in the present application, please refer to the above-mentioned embodiments of the crosstalk suppression circuit, and Figure 1 Any group of bridge arms and the corresponding setting of the bridge function circuit have been illustrated in the above-mentioned embodiments, and thus will not be described here.

[0079] The technical features of the above embodiments can be combined arbitrarily, and to make the description concise, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0080] The above-described embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

[0081] It also needs to be explained that in the present specification, the 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 such actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations 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 can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises a", "comprising", or "includes" does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

Claims

1. A crosstalk suppression circuit, characterized in that: A MOSFET drive circuit used in a bridge functional circuit, the bridge functional circuit comprising multiple groups of bridge arms, wherein corresponding MOSFET drive circuits are provided for the MOSFET located in the upper bridge arm and the MOSFET located in the lower bridge arm of any group of bridge arms; the MOSFET drive circuit comprises a drive resistor, a clamping matching resistor, and a first voltage stabilizing diode; the crosstalk suppression circuit comprises a first capacitor, a controllable switch module, and a bleeder resistor; The output end of the driving chip in the bridge functional circuit is connected to the gate of the MOSFET corresponding to the MOSFET driving circuit and the first end of the controllable switch module through the driving resistor, and the second end of the controllable switch module is connected to one end of the bleeder resistor; The source of the MOSFET is respectively connected to the other end of the bleeder resistor, one end of the clamping resistor, and the cathode of the first voltage-stabilizing diode; the other end of the clamping resistor is connected to the power supply end of the driver chip; the ground end of the driver chip, the anode of the first voltage-stabilizing diode, and the control end of the controllable switch module are connected, and the common end of the connections is grounded; The first capacitor is connected in parallel with the driving resistor, and the capacitance of the first capacitor is greater than the capacitance of the gate-source parasitic capacitance of the corresponding MOSFET; The controllable switch module is used to turn on when the gate-source parasitic capacitance of the corresponding MOSFET is discharged through the driving resistor; otherwise, it remains turned off.

2. The crosstalk suppression circuit according to claim 1, wherein: The driving resistor includes a first driving resistor, a second driving resistor and a third driving resistor; One end of the first driving resistor is connected to the positive output terminal of the driving chip, the other end of the first driving resistor is respectively connected to one end of the second driving resistor, one end of the third driving resistor and one end of the first capacitor, the other end of the first capacitor is respectively connected to the other end of the second driving resistor and the first end of the controllable switch module, and the common end of the connections is connected to the gate of the MOSFET; The other end of the third driving resistor is connected to the negative output end of the driving chip.

3. The crosstalk suppression circuit according to claim 1, wherein: It also includes voltage divider resistors; One end of the voltage divider resistor is connected to the gate of the corresponding MOSFET, and the other end is connected to the source of the MOSFET.

4. The crosstalk suppression circuit according to claim 1, wherein: Also includes a second voltage stabilizing diode and a third voltage stabilizing diode; The anode of the second Zener diode is connected to the anode of the third Zener diode, the cathode of the second Zener diode is connected to the gate of the corresponding MOSFET, and the cathode of the third Zener diode is connected to the source of the MOSFET.

5. The crosstalk suppression circuit according to claim 1, wherein: The device further includes a clamping capacitor connected in parallel with the first voltage stabilizing diode.

6. The crosstalk suppression circuit according to any one of claims 1 to 5, characterized in that: The controllable switch module includes a controllable switch and a protective resistor; The control end of the controllable switch is connected to one end of the protection resistor, the other end of the protection resistor serves as the control end of the controllable switch module, the first end of the controllable switch serves as the first end of the controllable switch module, and the second end of the controllable switch serves as the second end of the controllable switch module.

7. The crosstalk suppression circuit according to claim 6, wherein: The controllable switch module further includes a diode; The anode of the diode is connected to the first end of the controllable switch, and the cathode of the diode serves as the first end of the controllable switch module.

8. The crosstalk suppression circuit according to claim 6, wherein: The controllable switch is an NPN transistor.

9. A MOSFET driving circuit, characterized in that: It includes a driving resistor, a clamping matching resistor and a first voltage stabilizing diode, and also includes the crosstalk suppression circuit according to any one of claims 1 to 8; The crosstalk suppression circuit is connected to the driving resistor, the clamping matching resistor and the first voltage stabilizing diode respectively.

10. A bridge functional circuit, characterized in that: It includes multiple groups of bridge arms, each group of bridge arms includes a first MOSFET located in an upper bridge arm and a second MOSFET located in a lower bridge arm; The bridge functional circuit further includes the MOSFET driving circuit as claimed in claim 9 , wherein the first MOSFET is connected to a corresponding MOSFET driving circuit for driving the first MOSFET, and the second MOSFET is connected to a corresponding MOSFET driving circuit for driving the second MOSFET.

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