CN-224204974-U - Bootstrap driving circuit and half-bridge circuit

CN224204974UCN 224204974 UCN224204974 UCN 224204974UCN-224204974-U

Abstract

The application provides a bootstrap driving circuit and a half-bridge circuit, which relate to the technical field of semiconductors, wherein the bootstrap driving circuit comprises: the device comprises an independent power supply, an upper bridge arm pipe, a lower bridge arm pipe, an upper bridge arm bootstrap module, a lower bridge arm bootstrap module, an upper bridge arm negative pressure module and a lower bridge arm negative pressure module. According to the technical scheme provided by the application, before the lower bridge arm pipe is opened, the lower bridge arm negative pressure module establishes voltage after being charged through a loop formed by the independent power supply and the lower bridge arm negative pressure module. When the upper bridge arm bootstrap module is switched on, a circuit formed by the independent power supply, the upper bridge arm bootstrap module, the anti-reverse diode, the lower bridge arm tube and the lower bridge arm negative pressure module charges the capacitor to establish voltage, so that stable negative pressure is provided for the upper bridge arm tube and the lower bridge arm tube, stable switching-off of the upper bridge arm tube and the lower bridge arm tube can be ensured, and reliability and stability of the bootstrap driving circuit can be improved.

Inventors

GOU HONGYAN
SHI WEI
GANG LI

Assignees

西安图为电气技术有限公司

Dates

Publication Date: 20260505
Application Date: 20250217

Claims (10)

1. The bootstrap driving circuit is characterized by comprising an independent power supply, an upper bridge arm pipe, a lower bridge arm pipe, an upper bridge arm bootstrap module, a lower bridge arm bootstrap module, an upper bridge arm negative pressure module and a lower bridge arm negative pressure module; The first end of the upper bridge arm bootstrap module is connected with the positive electrode end of the independent power supply, and the second end of the upper bridge arm bootstrap module is connected with the second end of the upper bridge arm negative voltage module through a charging diode; The first end of the upper bridge arm negative pressure module is connected with the second end of the upper bridge arm bootstrap module through an anti-reflection diode, the second end of the upper bridge arm negative pressure module is connected with the second end of the upper bridge arm pipe, and the first end of the upper bridge arm pipe is connected with the positive electrode of the high-voltage bus; The first end of the lower bridge arm bootstrap module is connected with the positive end of the independent power supply, the second end of the lower bridge arm bootstrap module is connected with the negative end of the independent power supply and the first end of the lower bridge arm negative pressure module respectively, the second end of the lower bridge arm negative pressure module is connected with the second end of the lower bridge arm pipe, the first end of the lower bridge arm pipe is connected with the second end of the upper bridge arm pipe, and the second end of the lower bridge arm pipe is connected with the negative electrode of the high-voltage bus.
2. The bootstrap driving circuit of claim 1, wherein the upper leg bootstrap module includes a first bootstrap diode and a first bootstrap capacitor; The first end of the first bootstrap diode is connected with the positive electrode end of the independent power supply, the second end of the first bootstrap diode is connected with the first end of the first bootstrap capacitor, and the second end of the first bootstrap capacitor is connected with the second end of the upper bridge arm negative voltage module through the charging diode.
3. The bootstrap drive circuit of claim 2, wherein a second end of the first bootstrap capacitor is connected to a first end of the upper leg negative voltage module through the anti-turn diode.
4. The bootstrap drive circuit of claim 2, wherein the bootstrap drive circuit further comprises a first current-limiting resistor and a second current-limiting resistor; The first end of the first current limiting resistor is connected between the first bootstrap diode and the first bootstrap capacitor, and the second end of the first current limiting resistor is connected with the second end of the upper bridge arm negative voltage module; The first end of the second current limiting resistor is connected with the positive end of the independent power supply, and the second end of the second current limiting resistor is connected with the second end of the lower bridge arm negative pressure module.
5. The bootstrap drive circuit of claim 4, further comprising a third current limiting resistor; the third current limiting resistor is connected in series between the upper bridge arm bootstrap module and the independent power supply.
6. The bootstrap driving circuit of any of claims 1-5, further comprising a first driving resistor and a second driving resistor; the first driving resistor is connected with the control end of the upper bridge arm pipe; And the second driving resistor is connected with the control end of the lower bridge arm pipe.
7. The bootstrap driving circuit of any of claims 1-5, further comprising a first gate resistor and a second gate resistor; The first gate resistor is connected between the control end and the second end of the upper bridge arm pipe; The second gate resistor is connected between the control end and the second end of the lower bridge arm tube.
8. The bootstrap driving circuit of any one of claims 1 to 5, wherein the upper bridge arm negative voltage module comprises a first negative voltage capacitor and a first voltage regulator tube; The positive electrode of the first voltage stabilizing tube is connected with the first end of the first negative voltage capacitor, and the negative electrode of the first voltage stabilizing tube is connected with the second end of the first negative voltage capacitor; The first end of the first negative-pressure capacitor is connected with the second end of the upper bridge arm bootstrap module, and the second end of the first negative-pressure capacitor is connected with the second end of the upper bridge arm pipe; The lower bridge arm negative pressure module comprises a second negative pressure capacitor and a second voltage stabilizing tube; the positive electrode of the second voltage stabilizing tube is connected with the first end of the second negative voltage capacitor, and the negative electrode of the second voltage stabilizing tube is connected with the second end of the second negative voltage capacitor; The first end of the second negative-pressure capacitor is connected with the second end of the lower bridge arm bootstrap module, and the second end of the second negative-pressure capacitor is connected with the second end of the lower bridge arm pipe.
9. The bootstrap driving circuit of claim 8, further comprising a third voltage regulator tube; The lower bridge arm bootstrap module is connected with the independent power supply through the third voltage stabilizing tube, the positive electrode of the third voltage stabilizing tube is connected with the first end of the lower bridge arm bootstrap module, and the negative electrode of the third voltage stabilizing tube is connected with the positive electrode end of the independent power supply.
10. A half-bridge circuit comprising a drive chip and a bootstrap drive circuit as defined in any one of claims 1 to 9; The first positive pressure end of the driving chip is respectively connected with the first end of the lower bridge arm bootstrap module, the second end of the lower bridge arm negative pressure module and the control end of the lower bridge arm pipe; The first negative pressure end of the driving chip is respectively connected with the negative end of the independent power supply, the first end of the lower bridge arm bootstrap module and the second end of the lower bridge arm negative pressure module; the first output end of the driving chip is connected with the control end of the lower bridge arm pipe; the second positive voltage end of the driving chip is connected between the first bootstrap diode and the first bootstrap capacitor of the upper bridge arm bootstrap module, and the second positive voltage end of the driving chip is also connected with the second end of the upper bridge arm negative voltage module; The second negative pressure end of the driving chip is respectively connected with the first end of the upper bridge arm negative pressure module and the second end of the upper bridge arm bootstrap module; and a second output end of the driving chip is connected with a control end of the upper bridge arm pipe.

Description

Bootstrap driving circuit and half-bridge circuit Technical Field The application belongs to the technical field of semiconductors, and particularly relates to a bootstrap driving circuit and a half-bridge circuit. Background The bootstrap circuit is also called a boost circuit, and uses electronic elements such as a diode, a capacitor and the like to enable discharge voltage of the capacitor and power supply voltage to be overlapped, so that output voltage is increased. In the related art, as shown in fig. 1, a bootstrap circuit is generally used in a half-bridge circuit, an upper bridge arm Q1 is connected to a positive electrode (bus+) of a high-voltage BUS, and a lower bridge arm Q2 is connected to a negative electrode (BUS-) of the high-voltage BUS. In addition, the driving of the upper Bridge arm Q1 and the lower Bridge arm Q2 generally uses a Half-Bridge Driver (Half-Bridge Driver) chip, and the upper Half-Bridge power supply terminal VDDB of the Half-Bridge Driver chip generally uses a bootstrap mode to draw power from the power supply VDD. The bootstrap circuit may include a bootstrap capacitor C1, a bootstrap diode D1, and a current-limiting resistor R5. The voltage regulators DZ1 and C3 may provide a negative voltage circuit for driving the upper arm Q1, and the voltage regulators DZ2 and C4 may provide a negative voltage circuit for driving the lower arm Q2. However, the voltages of the capacitor C3 and the capacitor C4 must be established when the upper bridge arm Q1 and the lower bridge arm Q2 are turned on, and the capacitor C3 and the capacitor C4 have no voltage in the initial stage of the circuit, and when the turn-on threshold VGSth of the upper bridge arm Q1 and the lower bridge arm Q2 is smaller, the through-current stress of the upper bridge arm Q1 and the lower bridge arm Q2 will cause the damage to the upper bridge arm Q1 and the lower bridge arm Q2. Disclosure of utility model The application provides a bootstrap driving circuit and a half-bridge circuit, which solve the problem that in the prior art, when the opening threshold VGSth of an upper bridge arm tube Q1 and a lower bridge arm tube Q2 is smaller, the upper bridge arm tube Q1 and the lower bridge arm tube Q2 are damaged by direct overcurrent stress of the upper bridge arm tube Q1 and the lower bridge arm tube Q2. In order to achieve the above purpose, the application adopts the following technical scheme: In a first aspect, an embodiment of the present application provides a bootstrap driving circuit, where the bootstrap driving circuit includes an independent power supply, an upper bridge arm pipe, a lower bridge arm pipe, an upper bridge arm bootstrap module, a lower bridge arm bootstrap module, an upper bridge arm negative pressure module and a lower bridge arm negative pressure module; The first end of the upper bridge arm bootstrap module is connected with the positive electrode end of the independent power supply, and the second end of the upper bridge arm bootstrap module is connected with the second end of the upper bridge arm negative voltage module through a charging diode; The first end of the upper bridge arm negative pressure module is connected with the second end of the upper bridge arm bootstrap module through an anti-reflection diode, the second end of the upper bridge arm negative pressure module is connected with the second end of the upper bridge arm pipe, and the first end of the upper bridge arm pipe is connected with the positive electrode of the high-voltage bus; The first end of the lower bridge arm bootstrap module is connected with the positive end of the independent power supply, the second end of the lower bridge arm bootstrap module is connected with the negative end of the independent power supply and the first end of the lower bridge arm negative pressure module respectively, the second end of the lower bridge arm negative pressure module is connected with the second end of the lower bridge arm pipe, the first end of the lower bridge arm pipe is connected with the second end of the upper bridge arm pipe, and the second end of the lower bridge arm pipe is connected with the negative electrode of the high-voltage bus. Optionally, the upper bridge arm bootstrap module comprises a first bootstrap diode and a first bootstrap capacitor; The first end of the first bootstrap diode is connected with the positive electrode end of the independent power supply, the second end of the first bootstrap diode is connected with the first end of the first bootstrap capacitor, and the second end of the first bootstrap capacitor is connected with the second end of the upper bridge arm negative voltage module through the charging diode. Optionally, the second end of the first bootstrap capacitor is connected with the first end of the upper bridge arm negative pressure module through the anti-reflection diode. Optionally, the bootstrap driving circuit further comprises a first current limiting resistor and a second