CN216699812U - Suppression circuit, IGBT driver and system - Google Patents

Abstract

The application relates to a suppression circuit, an IGBT driver and a system. In the technical scheme, the suppression circuit is electrically connected to the IGBT chip. The IGBT chip comprises an IGBT and a current sensor. The suppression circuit comprises an input end, an output end, a grounding end, an inverter circuit and a switch tube. The input end is used for receiving a grid driving signal. The output end is electrically connected to the sampling end of the short-circuit protection circuit. The reference terminal of the short-circuit protection circuit is used for receiving a reference voltage. The grounding end is grounded, one end of the inverter circuit is electrically connected to the input end, and the first end of the switch tube is electrically connected to the other end of the inverter circuit. The second end of the switch tube is electrically connected to the output end, the third end of the switch tube is grounded, and the saturation voltage drop when the switch tube is conducted is lower than the reference voltage. The suppression circuit has simple layout and reliable function, and can effectively realize the function of preventing short circuit false triggering.

Description

Suppression Circuits, IGBT Drivers and Systems

technical field

The present application relates to the field of high-voltage power integrated circuits, and in particular, to a suppression circuit, an IGBT driver and a system.

Background technique

With the development of electric vehicles, the performance and safety requirements of automotive Insulated Gate Bipolar Transistor (IGBT) devices/chips are getting higher and higher, and the method of integrating current sensors in IGBT chips is widely used in automotive field. , for faster and safer short-circuit protection. However, the short-circuit protection function is limited by the characteristics of the device (ie, the IGBT chip), and a diverted current will be generated during the turn-off transient of the device. The transfer current will increase the sampling voltage and cause the short-circuit protection function to be falsely triggered, resulting in the overall shutdown.

Utility model content

In view of this, the present application provides a suppression circuit, an IGBT driver and a system. Among them, the function of the suppression circuit is reliable, the layout is simple, and the short-circuit false triggering can be effectively prevented.

In a first aspect, an embodiment of the present application provides a suppression circuit, which is electrically connected to an IGBT chip. The IGBT chip includes an IGBT and a current sensor. The gate of the IGBT is used to receive the gate driving signal. The collector of the IGBT is used to receive the supply current. The emitter of the IGBT is grounded, and the first terminal of the current sensor is electrically connected to the gate of the IGBT. The second end of the current sensor is electrically connected to the collector of the IGBT. The third terminal of the current sensor is electrically connected to the emitter of the IGBT through the sampling resistor. The third end of the current sensor is also electrically connected to the sampling end of the short-circuit protection circuit. The third end of the current sensor is used to collect the current flowing through the IGBT, and convert the collected current into a sampling voltage and output it to the sampling end of the short-circuit protection circuit. The reference terminal of the short-circuit protection circuit is used for receiving the reference voltage. The suppression circuit includes an input end, an output end, a ground end, an inverting circuit and a switch tube. The input terminal is used for receiving the gate driving signal. The output terminal is electrically connected to the sampling terminal of the short-circuit protection circuit. The grounding end is grounded, one end of the inverting circuit is electrically connected to the input end, and the first end of the switch tube is electrically connected to the other end of the inverting circuit. The second end of the switch tube is electrically connected to the output end, the third end of the switch tube is grounded, and the saturation voltage when the switch tube is turned on is lower than the reference voltage.

Obviously, in the first aspect of the present application, the layout of the suppression circuit is simple and the function is reliable. The suppression circuit receives the gate drive signal through the input terminal, and the gate drive signal is consistent with the on and off states of the device (ie, the IGBT chip). In this way, when the IGBT chip is turned off, the suppression circuit will start to work, and the switch tube will be turned on, and the turned-on switch tube will forcibly pull down the sampling voltage across the sampling resistor to its saturation voltage drop. Since the saturation voltage when the switch is turned on is lower than the reference voltage, the short-circuit protection circuit will not work, that is, the short-circuit protection will not be triggered, which can effectively suppress the interference of the transfer current of the IGBT chip to the short-circuit detection during the turn-off process and avoid short-circuit detection. Short circuit false protection, that is, to effectively realize the function of preventing short circuit false triggering. When the IGBT chip is working, the switch tube is turned off, which has almost no effect on the sampling voltage. In this way, the short-circuit protection circuit can work normally. Furthermore, by setting the suppression circuit, there is no need to reduce the sampling resistance, the sampling accuracy and sensitivity can be effectively maintained, and the performance can be effectively improved. In addition, by arranging the suppression circuit, the dependence of the short-circuit protection circuit on the device consistency can be reduced, that is, it is no longer necessary to control the process of the IGBT chip, thereby effectively increasing the device yield and reducing the cost.

In one possible design, the suppression circuit also includes pull-up resistors. One end of the pull-up resistor is electrically connected to the third end of the switch tube, and the other end is electrically connected to the power supply. Obviously, in this design, in order to ensure the control effect of the suppression circuit, a pull-up resistor can be set, and usually the resistance of the pull-up resistor is much larger than that of the sampling resistor.

In one possible design, the inverting circuit includes a first resistor, a second resistor and a switching element. One end of the first resistor is electrically connected to the input end, and the other end is electrically connected to the first end of the switching element. The second end of the switching element is electrically connected to the power source through a second resistor. The third terminal of the switching element is grounded. Obviously, in this design, the inverting circuit can include simple components, which are small in area and low in power consumption, and the components used are suitable for integration.

In one possible design, the inverting circuit is an inverter. Obviously, in this design, the circuit structure of the suppression circuit can be further simplified by making the inverter directly form an inverting circuit.

In a possible design, the switch element is a triode, the first end of the switch element is the base, the second end is the collector, and the third end is the emitter. Alternatively, the switching element is a MOS transistor, the first terminal of the switching element is the gate, the second terminal is the drain, and the third terminal is the source. Obviously, in this design, the types of switching elements and/or switching tubes are not limited. For example, the switch element and/or the switch tube may be any one of the following: a triode or a metal oxide semiconductor field effect transistor (MetalOxideSemiconductor Filed Effect Transistor, MOSFET, hereinafter referred to as a MOS tube) and the like. When the switch tube is a MOS tube, it may specifically be a PMOS tube or an NMOS tube, which is not specifically limited in this embodiment of the present application.

In a possible design, the switch tube is a triode, the first end of the switch tube is the base, the second end is the collector, and the third end is the emitter. Alternatively, the switch tube is a MOS tube, the first end of the switch tube is the gate, the second end is the drain, and the third end is the source. Obviously, in this design, the types of switching elements and/or switching tubes are not limited. For example, the switch element and/or the switch tube may be any one of the following: a triode or a metal oxide semiconductor field effect transistor (MetalOxideSemiconductor Filed Effect Transistor, MOSFET, hereinafter referred to as a MOS tube) and the like. When the switch tube is a MOS tube, it may specifically be a PMOS tube or an NMOS tube, which is not specifically limited in this embodiment of the present application.

In a possible design, the suppression circuit is arranged in the IGBT driver, and the IGBT driver is used for outputting the gate driving signal. Obviously, in this design, since the components used in the suppression circuit are suitable for integration, they can be integrated into the IGBT driver. That is, an IGBT driver integrated with a suppression circuit can be formed, which can effectively strengthen its protection performance and improve the competitiveness of chip products.

In a second aspect, an embodiment of the present application provides an IGBT driver, where the IGBT driver includes a pulse width modulation (pulse width modulation, PWM) module and a short circuit protection circuit. The PWM module is used to output the gate drive signal to the IGBT chip. The short-circuit protection circuit is electrically connected to the IGBT chip to provide a short-circuit protection function for the IGBT chip. The IGBT driver also includes a suppression circuit as in the first aspect and possible designs. The suppression circuit is used for receiving the gate driving signal, and the suppression circuit is also electrically connected to the sampling end of the short-circuit protection circuit and the IGBT chip.

In a possible design, the input end of the suppression circuit is electrically connected to the PWM module for receiving the gate driving signal.

In one possible design, the IGBT driver also includes a transformer. The input end of the suppression circuit is electrically connected to the controller through a transformer for receiving a control signal of the controller. The gate drive signal is output after the control signal passes through the transformer.

In a third aspect, an embodiment of the present application provides an IGBT driving system, where the IGBT driving system includes an IGBT chip. The IGBT drive system also includes an IGBT driver and a suppression circuit as in the first aspect and possible designs. The suppression circuit is electrically connected to the IGBT chip and the IGBT driver, and the IGBT chip is electrically connected to the IGBT driver.

In a fourth aspect, the embodiments of the present application provide another IGBT driving system, where the IGBT driving system includes an IGBT chip. The IGBT drive system also includes an IGBT driver as in the second aspect and possible designs, the IGBT driver being electrically connected to the IGBT chip.

In addition, for the technical effect brought by any of the possible design methods in the second aspect to the fourth aspect, reference may be made to the technical effect brought by different design methods in the correlation of the suppression circuit part, which will not be repeated here.

Description of drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only These are some embodiments of the present application, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

FIG. 1 is a schematic diagram of an application of a suppression circuit provided by an embodiment of the present application;

2 is a schematic diagram of an internal structure of an IGBT chip provided by an embodiment of the present application;

FIG. 3 is a schematic diagram of the circuit connection between the IGBT chip shown in FIG. 2 and the IGBT driver and the controller;

4 is a schematic diagram of an equivalent circuit and a voltage signal of an IGBT chip and a sampling resistor provided by an embodiment of the present application;

5 is a schematic diagram of reducing the sampling voltage by increasing the gate turn-on voltage of the current sensor;

6 is a schematic circuit diagram of a suppression circuit, an IGBT chip, an IGBT driver and a controller provided by an embodiment of the present application;

7a to 7e are another schematic circuit diagram of the suppression circuit provided by the embodiment of the application;

8 is a schematic circuit diagram of an IGBT driver, an IGBT chip and a controller provided by an embodiment of the present application;

9 is another schematic circuit diagram of an IGBT driver, an IGBT chip and a controller provided by an embodiment of the present application;

10 is a schematic structural diagram of an IGBT drive system provided by an embodiment of the application;

FIG. 11 is another schematic structural diagram of an IGBT driving system provided by an embodiment of the present application.

Description of main component symbols

Suppression circuits 100, 100a, 100b, 100c, 100d, 100e, 35, 35a, 501, 604

IGBT chips 200, 503, 602

IGBT drivers 300, 300a, 300b, 502, 601

Controllers 400, 504, 603

IGBT 201

Current sensor 202

Gate pin J1

First Emitter Pin J2

Second Emitter Pin J3

Collector Pin J4

PWM module 31

Short circuit protection circuit 33

First input pin 301

Output pin 302

Feedback pin 303

Ground pin 304

Sampling side 331

Reference terminal 332

Reference voltage Vref

Sampling voltage Vsc

Voltage signal Vce

Input 101

output 102

Ground terminal 103

The first resistor R1

Second resistor R2

Switching elements T1, T1a

Switch tube T2, T2a, T2d

Pull-up resistor R3

Power Vcc

Inverting circuit 104

Inverter T3

Transformer 36

Second input pin 305

Resistance Rg

Sampling resistor Rshunt

Gate drive signal VGG

IGBT drive system 500, 600

The following specific embodiments will further illustrate the present application in conjunction with the above drawings.

Detailed ways

It should be understood that unless otherwise specified in this application, "/" means or means, for example, A/B can mean A or B. In this application, "and/or" is only an association relationship to describe associated objects, indicating that there can be three kinds of relationships, for example, A and/or B, it can mean that A exists alone, A and B exist simultaneously, and there are independent B these three cases. "At least one" means one or more, and "plurality" means two or more.

In this application, "exemplary," "in some embodiments," "in other embodiments," and the like are used to mean by way of example, illustration, or illustration. Any embodiment or design described in this application as "exemplary" should not be construed as preferred or advantageous over other embodiments or designs. Rather, the use of the word example is intended to present a concept in a concrete way.

In addition, terms such as "first" and "second" involved in this application are only used for the purpose of distinguishing and describing, and should not be interpreted as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Not to be construed as indicating or implying order.

In this application, "electrical connection" should be understood in a broad sense, for example, "electrical connection" can refer to a physical direct connection, or an electrical connection through an intermediate medium, that is, an indirect connection, such as through resistance, inductance , or connections made by other electronic devices.

With the development of electric vehicles, the performance and safety requirements of automotive Insulated Gate Bipolar Transistor (IGBT) devices/chips are getting higher and higher, and the method of integrating current sensors in IGBT chips is widely used in automotive field. , for faster and safer short-circuit protection. However, the short-circuit protection function is limited by the characteristics of the device (ie, the IGBT chip), and a diverted current will be generated during the turn-off transient of the device. The transfer current will increase the sampling voltage and cause the short-circuit protection function to be falsely triggered, resulting in the overall shutdown.

Therefore, the embodiments of the present application provide a suppression circuit, an IGBT driver and a system. Among them, the function of the suppression circuit is reliable, the layout is simple, and the short-circuit protection function can be effectively prevented from being triggered by mistake.

In order to make those skilled in the art better understand the technical solutions provided by the embodiments of the present application, the following first introduces the application scenarios of the suppression circuits provided by the embodiments of the present application.

Please refer to FIG. 1 . FIG. 1 is an application schematic diagram of a suppression circuit 100 provided by an embodiment of the present application. The suppression circuit 100 is electrically connected to the IGBT chip 200 and the IGBT driver 300 . The IGBT chip 200 is also electrically connected to the IGBT driver 300 .

Please refer to FIG. 2 together. FIG. 2 is a schematic diagram of the internal structure of the IGBT chip 200 . As shown in FIG. 2 , the IGBT chip 200 includes at least an IGBT 201 and a current sensor 202 . The current sensor 202 is integrated inside the IGBT chip 200 . In some embodiments, the current sensor 202 is also an IGBT. That is, in one embodiment, the IGBT chip 200 includes two IGBTs, one of which is the main IGBT, and the turn-off of the IGBT chip 200 is consistent with the turn-off of the IGBT chip 200 . The other IGBT is the detection IGBT to detect the current flowing through the main IGBT. It can be understood that, in the embodiments of the present application, for the convenience of description, the following description is given by taking the current sensor 202 as an IGBT as an example. Of course, in this embodiment of the present application, the type of the current sensor 202 is not limited.

The gate of the IGBT 201 is electrically connected to the gate of the current sensor 202 and is electrically connected to the gate pin J1 of the IGBT chip 200 for receiving a gate driving signal. The emitter of the current sensor 202 and the emitter of the IGBT 201 are electrically connected to the first emitter pin J2 and the second emitter pin J3 of the IGBT chip 200 , respectively. The first emitter pin J2 is used for outputting the sampling current, and the second emitter pin J3 is grounded. The collector of the IGBT 201 is electrically connected to the collector of the current sensor 202 and is electrically connected to the collector pin J4 of the IGBT chip 200 for receiving the main current (ie, the power supply current).

Please refer to FIG. 3 together. FIG. 3 is a schematic diagram of the circuit connection of the IGBT chip 200 , the IGBT driver 300 and the controller 400 . As shown in FIG. 3 , the IGBT driver 300 is electrically connected to the controller 400 . The controller 400 may be a Microcontroller Unit (MCU) for outputting control signals to the IGBT driver 300 .

Exemplarily, the IGBT driver 300 is a gate driving chip, and a pulse width modulation (PWM) module 31 and a short circuit protection circuit 33 are provided inside the IGBT driver 300 . The IGBT driver 300 further includes at least a first input pin 301 , an output pin 302 , a feedback pin 303 and a ground pin 304 . The first input pin 301 is electrically connected to the controller 400 and is electrically connected to the input end of the PWM module 31 for receiving the control signal from the controller 400 and inputting it to the PWM module 31 . The output pin 302 is electrically connected to the output end of the PWM module 31, and is electrically connected to the gate pin J1 of the IGBT chip 200 through the resistor Rg (ie, the gate of the IGBT 201 and the gate of the current sensor 202 in the IGBT chip 200), using To output the gate driving signal VGG to the IGBT chip 200 . The gate driving signal VGG is used to drive the IGBT chip 200 to work. The feedback pin 303 is electrically connected to the sampling terminal 331 of the short-circuit protection circuit 33 and is electrically connected to the first emitter pin J2 of the IGBT chip 200 (ie, the emitter of the current sensor 202 ) for receiving the sampling from the IGBT chip 200 current or sampled voltage. The reference terminal 332 of the short-circuit protection circuit 33 is used for receiving the reference voltage Vref. The ground pin 304 is grounded.

It can be understood that, in this embodiment of the present application, the current sensor 202 is equivalent to a current mirror and is used to detect the current flowing through the IGBT 201 , and the sampled current is proportional to the current of the IGBT 201 , for example, 1:10000. In addition, in order to convert the current signal sampled by the current sensor 202 into a voltage signal and detect it, it is usually necessary to connect the emitter of the current sensor 202 (ie the first emitter pin J2 ) and the emitter of the IGBT 201 (ie the second emitter Connect the sampling resistor Rshunt between the pole pins J3), as shown in Figure 3. In this way, the sampling voltage Vsc across the sampling resistor Rshunt can be fed back to the short-circuit protection circuit 33 through the feedback pin 303, and when the sampling voltage Vsc exceeds the protection threshold (for example, 1V) of the short-circuit protection circuit 33, the sampling voltage Vsc can trigger the short-circuit protection Short circuit protection function of circuit 33. When the sampling voltage Vsc does not exceed the protection threshold (for example, 1V) of the short-circuit protection circuit 33, since the sampling voltage Vsc is fed back to the short-circuit protection circuit 33 through the feedback pin 303, the short-circuit protection circuit 33 does not work, that is, the short-circuit protection is not triggered. Short circuit protection function of circuit 33.

Please refer to FIG. 4 together. FIG. 4 is a schematic diagram of the equivalent circuit of the IGBT chip 200 and the sampling resistor Rshunt shown in FIG. 3 and the voltage signal Vce. When the IGBT chip 200 is in the off stage, the voltage signal Vce between the collector and the emitter gradually rises. During the voltage rise, the junction capacitances Cgc and Cce of the current sensor 202 respectively generate transfer currents Ice and Igc. Among them, a part of the transfer current Igc (eg, Igc 1 ) flows into the resistor Rg, and the other part (eg, Igc2 ) flows into the sampling resistor Rshunt through the junction capacitance Cge. Likewise, the transfer current Ice also flows through the sampling resistor Rshunt. The transfer current is proportional to the junction capacitance and the voltage rise slope. In this way, the transfer currents Ice, Igc2 will cause the sampling voltage Vsc across the sampling resistor Rshunt to exceed the protection threshold, thereby erroneously triggering the short-circuit protection function of the short-circuit protection circuit 33, resulting in the overall shutdown.

Please also refer to FIG. 5 . FIG. 5 is a schematic diagram of reducing the sampling voltage Vsc by increasing the gate turn-on voltage of the current sensor 202 . Specifically, by increasing the gate turn-on voltage Vth of the current sensor 202, the current sensor 202 is turned off before the IGBT 201, and the sampling current will start to drop earlier than the IGBT 201. When the sampling current decreases, the sampling voltage Vsc across the corresponding sampling resistor Rshunt also decreases, thereby reducing the probability that the sampling voltage Vsc triggers the protection threshold.

Please refer to FIG. 6 together. FIG. 6 is a schematic circuit diagram of the suppression circuit 100 , the IGBT chip 200 , the IGBT driver 300 and the controller 400 according to an embodiment of the present application. As shown in FIG. 6 , in the embodiment of the present application, the electrical connection relationship between the IGBT chip 200 and the IGBT driver 300 and the controller 400 is similar to that in FIG.

As shown in FIG. 6 , the suppression circuit 100 includes an input terminal 101 , an output terminal 102 and a ground terminal 103 . For example, the input terminal 101 of the suppression circuit 100 is electrically connected to the output pin 302 of the IGBT driver 300 for receiving the gate driving signal VGG output from the IGBT driver 300 .

The output terminal 102 of the suppression circuit 100 is electrically connected to the first emitter pin J2 of the IGBT chip 200 and the feedback pin 303 of the IGBT driver 300 . The ground terminal 103 of the suppression circuit 100 is grounded. For example, in some of the embodiments, the ground terminal 103 of the suppression circuit 100 is electrically connected to the second emitter pin J3 of the IGBT chip 200 and the ground pin 304 of the IGBT driver 300 , and is grounded in common.

In some embodiments, the suppression circuit 100 includes a first resistor R1, a second resistor R2, a switch element T1, a switch transistor T2 and a pull-up resistor R3.

It can be understood that the type of switching element and/or switching tube can be any of the following: triode or metal oxide semiconductor field effect transistor (Metal Oxide Semiconductor Field Effect Transistor, MOSFET, hereinafter referred to as MOS tube) and the like. When the switch tube is a MOS tube, it may specifically be a PMOS tube or an NMOS tube, which is not specifically limited in this embodiment of the present application.

As shown in FIG. 6 , in this embodiment, the switching element T1 and the switching transistor T2 are both triodes as an example for description. Specifically, the first terminal (eg, the base) of the switching element T1 is electrically connected to the input terminal 101 through the first resistor R1. The second terminal (eg, the collector) of the switching element T1 is electrically connected to the power supply Vcc through the second resistor R2. The collector of the switching element T1 is also electrically connected to the first terminal (eg, the base) of the switching transistor T2. The third terminal (eg, the emitter) of the switching element T1 is electrically connected to the third terminal (eg, the emitter) of the switching transistor T2, and is electrically connected to the ground terminal 103 (ie, the ground). The second end (eg, the collector) of the switch tube T2 is electrically connected to the power supply Vcc through the pull-up resistor R3. The collector of the switch tube T2 is also electrically connected to the output end 102 , that is, to the feedback pin 303 of the IGBT driver 300 and the first emitter pin J2 of the IGBT chip 200 (ie, the emitter of the current sensor 202 ).

It can be understood that, as shown in FIG. 6 , the first resistor R1 , the second resistor R2 and the switching element T1 constitute the inverter circuit 104 .

The working principle of the suppression circuit 100 will be described in detail below with reference to FIG. 6 .

When the IGBT driver 300 outputs the gate drive signal VGG to the IGBT chip 200 through the output pin 302 , and the gate drive signal VGG is at a low level, the IGBT chip 200 enters the off state, and the suppression circuit 100 receives the gate drive through the input terminal 101 signal VGG and start working. At this time, the switch element T1 is turned off, and the switch tube T2 is turned on. Since the output terminal 102 and the ground terminal 103 of the suppression circuit 100 are respectively electrically connected to the first emitter pin J2 and the second emitter pin J3 of the IGBT chip 200 , and the first emitter pin J2 and the second emitter pin J2 A sampling resistor Rshunt is connected between the pins J3. In this way, when the switch tube T2 is turned on, the sampling voltage Vsc across the sampling resistor Rshunt is forcibly pulled down to the saturation voltage drop of the switch tube T2 and output to the sampling terminal 331 of the short circuit protection circuit 33 through the feedback pin 303 .

It can be understood that, in the embodiment of the present application, the saturation voltage drop of the switch tube T2 can be set to be lower than the protection threshold (ie, the reference voltage Vref) of the short-circuit protection circuit 33 . For example, in some embodiments, the protection threshold of the short-circuit protection circuit 33 is set to 1V, and the saturation voltage drop of the switch tube T2 is set to 0.1V. In this way, when the sampling voltage Vsc across the sampling resistor Rshunt is forcibly pulled down to the saturation voltage drop of the switch tube T2, since the saturation voltage drop of the switch tube T2 is lower than the protection threshold of the short-circuit protection circuit 33, the short-circuit protection circuit 33 does not work , that is, the short-circuit protection is not triggered, thereby eliminating the problem of the short-circuit protection function being triggered by mistake.

When the IGBT driver 300 outputs the gate driving signal VGG to the IGBT chip 200 through the output pin 302 and the gate driving signal VGG is at a high level, the switching element T1 in the suppression circuit 100 is turned on and the switching transistor T2 is turned off. That is to say, when the gate driving signal VGG is at a high level, it has almost no effect on the sampling voltage Vsc, so that the short-circuit protection circuit 33 works normally.

It can be understood that, in this embodiment of the present application, in order to ensure the control effect of the suppression circuit 100 , the resistance value of the pull-up resistor R3 is generally made much larger than the resistance value of the sampling resistor Rshunt. That is, R3>>Rshunt.

Obviously, in this embodiment of the present application, the gate driving signal output by the PWM module 31 is a PWM signal. In this way, the PWM signal can be used as the enable input of the suppression circuit 100, and the PWM signal is consistent with the on and off states of the device (ie, the IGBT chip 200). Wherein, when the IGBT chip 200 enters a turn-off mode/state, the PWM signal enables the suppression circuit 100 , thereby shielding the short-circuit protection function of the short-circuit protection circuit 33 . When the IGBT chip 200 enters the turn-on mode/state, the PWM signal turns off the suppression circuit 100 and the short-circuit protection circuit 33 operates normally.

It can be understood that, in this embodiment of the present application, the suppression circuit 100 can be enabled only by a negative voltage or a voltage of 0V. For example, the suppression circuit 100 can be enabled only when the gate driving signal VGG is at a low level, and its second-order soft turn-off function is not affected.

It can be understood that, in the embodiments of the present application, the specific structure of the suppression circuit 100 is not limited. For example, please refer to FIGS. 7a to 7e together for several other examples of suppression circuits. For example, as shown in FIG. 7a, the circuit structure of the suppression circuit 100a is similar to the circuit structure of the suppression circuit 100 shown in FIG. 6, the difference is that the switch element T1a and the switch tube T2a in the suppression circuit 100a are MOS transistors.

For example, as shown in FIG. 7b, the circuit structure of the suppression circuit 100b is similar to that of the suppression circuit 100a shown in FIG. 7a, the difference is that the pull-up resistor R3 is not set in the suppression circuit 100b. That is, the suppression circuit 100b omits the pull-up resistor R3 to further simplify the circuit, and the drain of the switch tube T2a in the suppression circuit 100b is directly connected to the output end 102 .

7c, the circuit structure of the suppression circuit 100c is similar to the circuit structure of the suppression circuit 100 shown in FIG. 6, the difference is that the suppression circuit 100 shown in FIG. The inverter circuit 104 formed by the second resistor R2 is directly replaced by the inverter T3. That is, as shown in FIG. 7c, the suppression circuit 100c includes an inverter T3, a switch tube T2 and a pull-up resistor R3. Wherein, one end of the inverter T3 is electrically connected to the input end 101 . The other end of the inverter T3 is electrically connected to the base of the switch tube T2.

For example, as shown in FIG. 7d , the circuit structure of the suppression circuit 100d is similar to the circuit structure of the suppression circuit 100c shown in FIG. 7c , the difference is that the switch transistor T2d in the suppression circuit 100d is a MOS transistor.

For example, as shown in FIG. 7e, the circuit structure of the suppression circuit 100e is similar to the circuit structure of the suppression circuit 100d shown in FIG. 7d, the difference is that the pull-up resistor R3 is not set in the suppression circuit 100e. That is, the suppression circuit 100e omits the pull-up resistor R3, and the drain of the switch tube T2d in the suppression circuit 100e is directly connected to the output terminal 102.

It can be understood that, referring to FIG. 6 again, as described above, the suppression circuit and the IGBT driver are provided independently. Of course, in other embodiments, the relationship between the suppression circuit and the IGBT driver is not limited. For example, since the suppression circuits all use resistors, triodes/MOS tubes, inverters and other components, the area is small and the power consumption is low, that is, the components used are suitable for integration. Therefore, in some embodiments, the suppression circuit can also be directly disposed in the IGBT driver, and the IGBT driver constitutes a chip integrated with the suppression circuit.

For example, please refer to FIG. 8 together. In one case, the embodiment of the present application further provides an IGBT driver 300a. The IGBT driver 300 a includes a PWM module 31 , a short circuit protection circuit 33 and a suppression circuit 35 . The PWM module 31 , the short circuit protection circuit 33 and the suppression circuit 35 are all disposed in the IGBT driver 300a. That is, the IGBT driver 300a integrates the suppression circuit 35 .

The suppressing circuit 35 may be the suppressing circuits 100, 100a-100e described above. For details, please refer to FIG. The input terminal 101 of the suppression circuit 35 is electrically connected to the output terminal of the PWM module 31 . The output end of the PWM module 31 is also electrically connected to the output pin 302 of the IGBT driver 300a for outputting the gate driving signal VGG. The output terminal 102 of the suppression circuit 35 is electrically connected to the sampling terminal 331 of the short-circuit protection circuit 33 . The sampling terminal 331 of the short-circuit protection circuit 33 is also electrically connected to the feedback pin 303 of the IGBT driver 300a. The ground terminal 103 of the suppression circuit 35 is electrically connected to the ground pin 304 .

It can be understood that when the suppression circuit 35 is working, only the first input pin 301 of the IGBT driver 300a needs to be electrically connected to the controller 400, and the output pin 302 of the IGBT driver 300a is electrically connected to the gate of the IGBT chip 200 through the resistor Rg The pole pin J1, the feedback pin 303 of the IGBT driver 300a is electrically connected to the first emitter pin J2 of the IGBT chip 200, and the ground pin 304 of the IGBT driver 300a is grounded. The specific working principle can refer to FIG. 6 and related descriptions thereof, which will not be repeated here.

As another example, as shown in FIG. 9 , in another case, the embodiment of the present application further provides an IGBT driver 300b. The IGBT driver 300b includes a PWM module 31, a short circuit protection circuit 33 and a suppression circuit 35a. The PWM module 31, the short circuit protection circuit 33 and the suppression circuit 35a are all disposed in the IGBT driver 300b. That is, the IGBT driver 300b integrates the suppression circuit 35a.

It can be understood that the IGBT driver 300b further includes a second input pin 305 and a transformer 36 . The transformer 36 is disposed in the IGBT driver 300b and is electrically connected to the second input pin 305 . The second input pin 305 is also used for electrical connection with the controller 400 to receive the control signal of the controller 400 .

The suppressing circuit 35a may be the suppressing circuits 100, 100a-100e described above, and for details, please refer to FIG. The input terminal 101 of the suppression circuit 35a is electrically connected to the second input pin 305 through the transformer 36 . The output terminal 102 of the suppression circuit 35b is electrically connected to the sampling terminal 331 of the short-circuit protection circuit 33 . The sampling terminal 331 of the short-circuit protection circuit 33 is also electrically connected to the feedback pin 303 of the IGBT driver 300b. The ground terminal 103 of the suppression circuit 35b is electrically connected to the ground pin 304 of the IGBT driver 300b.

It can be understood that when the suppression circuit 35a is working, it is only necessary to electrically connect the first input pin 301 and the second input pin 305 of the IGBT driver 300b to the controller 400, and connect the output pin 302 of the IGBT driver 300b through the resistor Rg It is electrically connected to the gate pin J1 of the IGBT chip 200, the feedback pin 303 of the IGBT driver 300b is electrically connected to the first emitter pin J2 of the IGBT chip 200, and the ground pin 304 of the IGBT driver 300b is grounded, For its specific working principle, reference may be made to FIG. 6 and related descriptions, which will not be repeated here.

It can be understood that, in this embodiment of the present application, the control signal output by the controller 400 is the same as the gate driving signal VGG, for example, both are low level or high level.

Obviously, by setting the suppression circuit in the embodiment of the present application, the IGBT driver and the IGBT chip can be combined to effectively suppress the false triggering of the short-circuit protection function in the IGBT driver. Furthermore, by setting the suppression circuit, it is no longer necessary to reduce the resistance value of the sampling resistor Rshunt in order to prevent the short-circuit protection function from being triggered by mistake, which can effectively improve the system performance, for example, improve the signal sampling accuracy and sensitivity. In addition, the setting of the suppression circuit makes it unnecessary to control the process of the IGBT chip, and it can be realized at the system application level without adding a process link, with reliable function and low cost. The above suppression circuit can also be directly integrated into the IGBT driver, thereby effectively improving product competitiveness.

To sum up, the above suppression circuit has at least the following beneficial effects:

(1) It can suppress the interference of the transfer current of the IGBT chip to the short-circuit detection during the turn-off process, and avoid short-circuit false protection, that is, the function of preventing short-circuit false triggering can be effectively realized.

(2) It is allowed to increase the sampling resistance to improve the short-circuit sampling accuracy and sensitivity and effectively improve the performance.

(3) The dependence of the short-circuit protection circuit on the device consistency is reduced, the device yield is increased, and the cost is reduced.

(4) The components used in the suppression circuit are suitable for integration and can be integrated into the IGBT driver. That is, an IGBT driver integrated with a suppression circuit can be formed, which can effectively strengthen its protection performance and improve the competitiveness of chip products.

It can be understood that, based on the suppression circuit, the IGBT driver and the IGBT chip provided in the above embodiments, the embodiment of the present application further provides an IGBT driving system, which will be described in detail below with reference to the accompanying drawings.

Referring to FIG. 10 , FIG. 10 is a schematic block diagram of an IGBT driving system 500 provided by an embodiment of the present application. The IGBT driving system 500 includes a suppression circuit 501 , an IGBT driver 502 , an IGBT chip 503 and a controller 504 . The controller 504 is electrically connected to the IGBT driver 502 . The suppression circuit 501 is provided independently from the IGBT driver 502 , and is electrically connected to the IGBT driver 502 and the IGBT chip 503 . The IGBT chip 503 is electrically connected to the IGBT driver 502 .

It can be understood that the suppression circuit 501 may be the suppression circuits 100, 100a-100e described above, and for details, please refer to FIG. The controller 504 , the IGBT driver 502 and the IGBT chip 503 are the above-mentioned controller 400 , the IGBT driver 300 and the IGBT chip 200 . For details, please refer to FIG.

Referring to FIG. 11 , FIG. 11 is a schematic block diagram of another IGBT driving system 600 according to an embodiment of the present application. The IGBT driving system 600 includes an IGBT driver 601 , an IGBT chip 602 and a controller 603 . The IGBT driver 601 is electrically connected to the IGBT chip 602 and the controller 603 . IGBT driver 601 includes suppression circuit 604 . That is, the IGBT driver 601 integrates the suppression circuit 604 .

It can be understood that the suppressing circuit 604 may be the suppressing circuits 100, 100a-100e described above, and for details, refer to FIG. The controller 603, the IGBT driver 601 and the IGBT chip 602 can be the above-mentioned controller 400, the IGBT drivers 300a, 300b and the IGBT chip 200. For details, please refer to FIG. 8, FIG. 9 and their related descriptions. No longer.

It should be understood that the various embodiments of the present application may be arbitrarily combined, for example, may be used alone or in combination with each other to achieve different technical effects, which are not limited.

The above contents are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (12)

1. A suppression circuit, electrically connected to a vehicle-mounted insulated gate bipolar transistor IGBT chip, the IGBT chip comprising an IGBT and a current sensor, the gate of the IGBT is used to receive a gate drive signal, the collector of the IGBT for receiving power supply current, the emitter of the IGBT is grounded, the first end of the current sensor is electrically connected to the gate of the IGBT, the second end of the current sensor is electrically connected to the collector of the IGBT, The third end of the current sensor is electrically connected to the emitter of the IGBT through the sampling resistor, the third end of the current sensor is also electrically connected to the sampling end of the short-circuit protection circuit, and the third end of the current sensor is used for collecting the current flowing through the IGBT, converting the collected current into a sampling voltage and outputting it to the sampling terminal of the short-circuit protection circuit, and the reference terminal of the short-circuit protection circuit is used to receive the reference voltage, and is characterized in that: The suppression circuit includes: an input terminal, the input terminal is used for receiving the gate driving signal; an output end, the output end is electrically connected to the sampling end of the short-circuit protection circuit; a ground terminal, the ground terminal is grounded; an inverting circuit, one end of the inverting circuit is electrically connected to the input end; a switch tube, the first end of the switch tube is electrically connected to the other end of the inverting circuit, the second end of the switch tube is electrically connected to the output end, and the third end of the switch tube is grounded, so The saturation voltage when the switch tube is turned on is lower than the reference voltage. 2 . The suppression circuit according to claim 1 , wherein the suppression circuit further comprises a pull-up resistor, one end of the pull-up resistor is electrically connected to the third end of the switch tube, and the other end is electrically connected to the third end of the switch tube. 3 . power supply. 3. The suppression circuit of claim 1, wherein the inverting circuit is an inverter. 4. The suppression circuit of claim 1, wherein the inverting circuit comprises a first resistor, a second resistor and a switching element, one end of the first resistor is electrically connected to the input end, the The other end of the first resistor is electrically connected to the first end of the switch element, the second end of the switch element is electrically connected to a power source through the second resistor, and the third end of the switch element is grounded. 5 . The suppression circuit according to claim 4 , wherein the switch element is a triode, the first end of the switch element is a base, the second end of the switch element is a collector, and the switch The third end of the element is the emitter; or, The switching element is a metal-oxide-semiconductor field-effect transistor (MOS transistor), the first terminal of the switching element is the gate, the second terminal of the switching element is the drain, and the third terminal of the switching element is the source . 6 . The suppression circuit of claim 1 , wherein the switch tube is a triode, the first end of the switch tube is a base, the second end of the switch tube is a collector, and the switch tube The third end of the tube is the emitter; or, The switch tube is a MOS tube, the first end of the switch tube is the gate, the second end of the switch tube is the drain, and the third end of the switch tube is the source. 7 . The suppression circuit of claim 1 , wherein the suppression circuit is arranged in an IGBT driver, and the IGBT driver is used for outputting the gate driving signal. 8 . 8. An IGBT driver, the IGBT driver comprises a pulse width modulation (pulse width modulation, PWM) module and a short circuit protection circuit, the PWM module is used to output a gate drive signal to an IGBT chip, and the short circuit protection circuit is electrically connected The IGBT chip is used to provide a short-circuit protection function for the IGBT chip, wherein the IGBT driver further comprises the suppression circuit according to any one of claims 1 to 6, the suppression circuit is used to receive the the gate driving signal, and the suppression circuit is also electrically connected to the sampling terminal of the short-circuit protection circuit and the IGBT chip. 9 . The IGBT driver of claim 8 , wherein the input end of the suppression circuit is electrically connected to the PWM module for receiving the gate driving signal. 10 . 10 . The IGBT driver according to claim 8 , wherein the IGBT driver further comprises a transformer, and the input end of the suppression circuit is electrically connected to the controller through the transformer to receive the control of the controller. 11 . signal, the gate driving signal is output after the control signal passes through the transformer. 11. An IGBT drive system, the IGBT drive system comprising an IGBT chip, characterized in that the IGBT drive system further comprises an IGBT driver and the suppression circuit according to any one of claims 1 to 6, the suppression A circuit is electrically connected to the IGBT chip and the IGBT driver, and the IGBT chip is electrically connected to the IGBT driver. 12. An IGBT driving system, the IGBT driving system comprising an IGBT chip, wherein the IGBT driving system further comprises the IGBT driver according to any one of claims 8 to 10, the IGBT driver being electrically connected to the IGBT chip.

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