TWI699062B - Power module having wide-bandgap power switch - Google Patents

Abstract

A power module operable to receive a driving signal includes a wide-bandgap power switch, a protection switch and a protection device. The wide-bandgap power switch is configured to receive the driving signal and make or break a circuit based on the driving signal. The protection switch is connected to the wide-bandgap power switch and configured to receive a protective driving signal and make or break the circuit based on the protective driving signal. When the protection switch is set to allow the passage of an electrical current, the wide-bandgap power switch is activated. The protection device determines if any of a maximum voltage, a minimum voltage, a phase, an operation frequency of the driving signal exceeds a standard value. If one of the measured data exceeds the standard value, a controller of the protection device is adapted to suspend an operation of an isolated driving unit and at the same time sends a trouble signal.

Description

Power module with wide band gap power switch

The present invention relates to a power module with a wide band gap power switch, in particular, it uses a protection device to detect whether a driving signal is abnormal to control the opening or closing of a protection switch to protect the power of a wide band gap power switch. Module.

500kHz)等優點，使得這類元件如氮化鎵(Gallium Nitride,GaN)功率開關具有低損失、高切換速度之特點。 As greenhouse gases increase year by year, causing global warming to become increasingly serious, the topic of energy conservation and carbon reduction has become the primary goal of the development of all countries. In recent years, due to the regulatory requirements of various countries (such as Energy Star Regulations, California Energy Regulations) and market demand, power supplies have continued to develop in the two directions of high efficiency and high power density. In the development of AC-to-DC converters and DC-to-DC converters, power switches have been dominated by silicon power devices in the past, and have gradually turned to wide bandgap (WBG) power devices. Because the wide band gap material has high breakdown voltage (High Breakdown Electric), high electron mobility (High Electron Mobility), high temperature operation (High Temperature Operation) and high frequency operation (

500kHz) and other advantages, so that such components such as Gallium Nitride (GaN) power switches have the characteristics of low loss and high switching speed.

However, the current GaN power switch is still difficult to popularize in product applications. The reasons are: (1) The gate drive voltage range of GaN is -10V to +7V, which is different from the gate drive voltage range of silicon power switches. It is +20V to -20V. Compared with the two, the gate drive voltage range of the GaN power switch is smaller, and the tolerance to the gate drive voltage oscillation becomes smaller; (2) Under high frequency operation, The parasitic inductance in the circuit is prone to current surges, and the parasitic capacitances generate voltage surges, which cause electromagnetic interference (EMI), and cause the phase of the gate drive voltage to deviate from the operating frequency, causing the gate The pole drive voltage therefore oscillates, causing damage to the power switch.

Therefore, the purpose of the present invention is to solve at least one reason why the above-mentioned wide band gap power switch is easily damaged, and to provide a power module with a wide band gap power switch.

Therefore, the power module of the present invention with a wide band gap power switch receives a driving signal, and includes a wide band gap power switch, a protection switch, and a protection device.

The wide band gap power switch can receive the driving signal and switch between the conducting state and the non-conducting state according to the driving signal, the protection switch is electrically connected to the wide band gap power switch, and the protection switch receives a protection driving signal, And switch between the conductive state and the non-conductive state according to the control of the protection driving signal. When the protection switch is switched to the conductive state, the wide band gap power switch starts to function, and the protection device generates according to a period of the driving signal. For the protection drive signal, the protection device detects whether a maximum voltage value and a minimum voltage value of the drive signal exceed the standard. If the protection device detects that one of the maximum voltage value and the minimum voltage value exceeds the standard, The protection device immediately controls the drive signal to be isolated from the wide band gap power switch, and controls the protection drive signal to be isolated from the protection switch, and the protection device detects whether a first phase and a first operating frequency of the drive signal are When an abnormality occurs, when the protection switch is turned on, the protection device detects whether a sensing current flowing from the wide band gap power switch through the protection switch exceeds the standard, converts the sensing current into a sensing voltage, and detects Detect whether a second phase and a second operating frequency of the sensing voltage are abnormal, if the protection device detects the first phase, the first operating frequency, the sensing current, the second phase and the first Two operating frequency When one of them exceeds the standard or an abnormality occurs, the protection device immediately controls the drive signal to be isolated from the wide band gap power switch, and controls the protection drive signal to be isolated from the protection switch.

Further, the wide band gap power switch includes a first terminal, a second terminal, and a control terminal. The protection switch includes a first terminal, a second terminal, and a control terminal. The first terminal of the protection switch Electrically connected to the second end of the wide bandgap power switch, the protection device includes an isolated driving unit, a voltage detecting unit, a current detecting unit, and a controller, and the isolated driving unit is electrically connected to the wide energy The control terminal of the gap power switch and the control terminal of the protection switch, the voltage detection unit is electrically connected to the isolated drive unit, the current detection unit is electrically connected to the second end of the protection switch, and the controller is electrically connected to the isolation type The drive unit, the voltage detection unit and the current detection unit, the drive signal is transmitted to the wide band gap power switch through the isolation drive unit, and the protection drive signal generated by the controller is transmitted to the isolation drive unit For the protection switch, in the process of transmitting the driving signal to the wide bandgap power switch, the voltage detecting unit captures the driving signal, and detects whether the maximum voltage value and the minimum voltage value of the driving signal exceed each Corresponding standards, and capture a positive edge signal and a negative edge signal of the drive signal, and transmit the result, the captured positive edge signal and the negative edge signal to the controller, and when the protection switch is turned on, The current detection unit captures a positive edge signal and a negative edge signal of the sensing voltage, and transmits the sense voltage, the captured positive edge signal and the negative edge signal to the controller, and the controller Determine whether the first phase of the drive signal and the first operating frequency are abnormal according to the positive edge signal and the negative edge signal of the drive signal, and judge according to the positive edge signal and the negative edge signal of the sensing voltage Whether the second phase of the sensing voltage and the second operating frequency are abnormal, and whether the sensing current exceeds the standard is determined according to the sensing voltage, if the controller receives any wrong result or judges any error or When abnormal, the isolated drive unit can be controlled to be turned off, and a fault notification signal can be generated.

Further, the voltage detection unit includes a first differential amplifier, an over-voltage protection circuit, a low-voltage protection circuit, and a pulse wave positive and negative edge detection circuit, and the first differential amplifier is electrically connected to the isolated drive unit , The over-voltage protection circuit is electrically connected to the first differential amplifier and the controller, the low-voltage protection circuit is electrically connected to the first differential amplifier and the controller, and the pulse detection circuit is electrically connected to the first A differential amplifier and the controller, the first differential amplifier captures the drive signal, and transmits the captured drive signal to the overvoltage protection circuit, the low voltage protection circuit, and the pulse wave positive and negative edge detection The over-voltage protection circuit detects whether the maximum voltage value of the driving signal exceeds the standard, and transmits the result to the controller, the low-voltage protection circuit detects whether the minimum voltage value of the driving signal exceeds the standard, and The result is transmitted to the controller, and the pulse wave positive and negative edge detection circuit captures the positive edge signal and the negative edge signal of the driving signal, and transmits it to the controller.

Further, the current detection unit includes a second differential amplifier and a pulse wave positive and negative edge detection circuit. The second differential amplifier is electrically connected to the second end of the protection switch and the controller. The pulse wave positive and negative edges The detection circuit is electrically connected to the second differential amplifier and the controller. When the protection switch is turned on, the protection switch forms a sensing resistor. The sensing current flows through the sensing resistor and is converted into the sensing voltage. The second differential amplifier captures the sensing voltage and transmits it to the controller and the pulse positive and negative edge detection circuit. The pulse positive and negative edge detection circuit captures the positive edge signal and the negative edge signal of the sensing voltage , And transmit the positive edge signal and the negative edge signal of the sensing voltage to the controller.

Furthermore, the wide band gap power switch is an enhanced gallium nitride transistor, and the protection switch is a silicon gold oxide half field effect transistor.

Further, the driving signal is a square wave with a first operating frequency, the protection driving signal is a square wave with a switching frequency, a period of the protection driving signal is equal to a period of the driving signal, and a period of the driving signal is The duty cycle is shorter than a duty cycle of the protection drive signal.

Further, the driving signal is a square wave with a first operating frequency, the protection driving signal is a square wave with a switching frequency, and a period of the protection driving signal is equal to multiple and complete cycles of the driving signal.

According to the above technical features, the following effects can be achieved:

1. The protection device can detect whether the voltage range of the driving signal input to the wide band gap power switch exceeds the standard. If any error or abnormality is detected, the wide band gap power switch is controlled to turn off. This can prevent the wide band gap power switch from receiving the oscillating driving signal and being damaged during use, so as to achieve the effect of protecting the wide band gap power switch.

2. Use the protection device to detect whether the first phase of the driving signal and the first operating frequency are abnormal, whether the sensing current of the wide band gap power switch has an overcurrent phenomenon, and the sensing Whether the second phase of the sensing voltage converted from the measurement current and the second operating frequency is abnormal, if any error or abnormality is detected, the wide band gap power switch is controlled to be turned off, and the wide energy can be avoided The gap power switch generates a current surge phenomenon and a voltage surge phenomenon, and causes the deviation of the first phase of the drive signal from the first operating frequency, and the difference between the second phase of the sensing voltage and the second operating frequency Deviation and damage during use to achieve the effect of protecting the wide band gap power switch.

3. The drive signal is directly transmitted from the isolated drive unit to the control terminal of the wide band gap power switch, so that electromagnetic interference is minimized to avoid the internal parasitic capacitance and parasitic inductance of the protection switch from affecting the wide band gap The conduction state and non-conduction state of the power switch.

4. The drive signal and the protection drive signal are respectively transmitted to the wide bandgap power switch and the protection switch via the isolation drive unit, so that the drive signal and the protection drive signal are not easily affected by impurities on the ground path. News interference.

(2): Protection device

(21): Isolated drive unit

(211): Isolated gate driver

(211a): The first isolated gate driver

(211b):Second isolated gate driver

(22): Voltage detection unit

(221): First differential amplifier

(222): Overvoltage protection circuit

(223): Low voltage protection circuit

(224): Pulse positive and negative edge detection circuit

(23): Current detection unit

(231): Second differential amplifier

(232): Pulse positive and negative edge detection circuit

(24): Controller

(M): Power module

(Q _W ): Wide band gap power switch

(Q _P ): Protection switch

(V _{gs_QW} ): drive signal

(V _{gs_QP} ): Protect drive signal

(PWM_Q _W ): drive signal

(PWM_Q _P ): Protect drive signal

(S _fault ): fault notification signal

(S _int ): Interrupt signal

(V _CC1 ): Input power

(V _CC2 ): Input power

(V _CC3 ): Input power

(V _in ): Input power

(M_QH): upper bridge power module

(M_QL): Lower bridge power module

(L ₁ ): Energy storage inductor

(C _o ): Output capacitance

(Z _D ): Zener diode

(Load): Load

(PWM _H ): drive signal

(PWM _L ): drive signal

(V _gs1 ): Drive signal of the upper bridge power module

(V _gs2 ): Protection drive signal of upper bridge power module

(V _gs3 ): Drive signal of the lower bridge power module

(V _gs4 ): Protection drive signal of the lower bridge power module

(i _L1(charge) ): Energy storage current

(i _{L1(discharge)} ): discharge current

[The first figure] is a circuit block diagram illustrating an embodiment of the power module with a wide band gap power switch of the present invention.

[The second figure] is a circuit diagram illustrating that the power module with a wide band gap power switch is applied to a single-phase synchronous rectification buck converter.

[Third Figure] is a timing diagram illustrating an operation timing of the single-phase synchronous rectification buck converter.

Based on the above technical features, the main effects of the power module with a wide band gap power switch of the present invention will be clearly presented in the following embodiments.

Referring to the first figure, an embodiment of a power module with a wide band gap power switch of the present invention. The power module M includes a wide band gap power switch Q _W , a protection switch Q _P , and a protection device 2.

The wide band gap power switch Q _W is an enhanced gallium nitride transistor. The wide band gap power switch Q _W includes a first terminal, a second terminal, and a control terminal. The control terminal can receive a drive The signal V _{gs_QW} , the driving signal V _{gs_QW} is a square wave with a first operating frequency, and the wide band gap power switch Q _W can be switched between a conducting state and a non-conducting state according to the driving signal V _{gs_QW} . In this example, the wide band gap power switch Q _W is an enhancement mode gallium nitride transistor, and the first terminal is a drain, the second terminal is a source, and the control terminal is a gate.

The protection switch Q _P is a silicon metal oxide half field effect transistor. The protection switch Q _P includes a first terminal, a second terminal, and a control terminal. The control terminal can receive a protection drive signal V _{gs_QP} . The driving signal V _{gs_QP} is a square wave with a switching frequency. The protection switch Q _P can be switched between a conducting state and a non-conducting state according to the protection driving signal V _{gs_QP} . The first end of the protection switch Q _P is electrically connected to the The second end of the wide band gap power switch Q _W , and when the protection switch Q _{P is} switched in the on state, the wide band gap power switch Q _W can begin to function. In this example, the protection switch Q _P is an N-channel SiO 2 MOSFET, and the first terminal is a drain, the second terminal is a source, and the control terminal is a gate.

The protection device 2 includes an isolated drive unit 21, a voltage detection unit 22, a current detection unit 23, and a controller 24.

The isolated driving unit 21 includes two isolated gate drivers 211. Each isolated gate driver 211 includes an input terminal, an output terminal, and a control terminal. For the convenience of description, one of the isolated gate drivers 211 is represented as a first isolated gate driver 211a, and the other isolated gate driver is represented as a second isolated gate driver 211b. The first isolated gate driver the output terminal of the gate driver 211a is electrically connected to the wide band gap control terminal of the power switch Q _W, and the second isolated gate driver output terminal 211b is electrically connected to the control terminal of the switch Q _P of the protection.

The voltage detection unit 22 includes a first differential amplifier 221, an over-voltage protection circuit 222, a low-voltage protection circuit 223, and a pulse detection circuit 224. The first differential amplifier 221 includes an input terminal and an output terminal. The input terminal of the first differential amplifier 221 is electrically connected to the output terminal of the first isolated gate driver 211a. The over-voltage protection circuit 222 includes an input terminal and an output terminal. The input terminal of the overvoltage protection circuit 222 is electrically connected to the output terminal of the first differential amplifier 221. The low voltage protection circuit 223 includes an input terminal and an output terminal. The input terminal of the low voltage protection circuit 223 is electrically connected to the output terminal of the first differential amplifier 221. The pulse wave positive and negative edge detection circuit 224 includes an input terminal and an output terminal. The input terminal of the pulse detection circuit 224 is electrically connected to the output terminal of the first differential amplifier 221.

The current detection unit 23 includes a second differential amplifier 231 and a pulse detection circuit 232. The second differential amplifier 231 includes an input terminal and an output terminal. The input terminal of the second differential amplifier 231 is electrically connected to the second terminal of the protection switch Q _P. The pulse wave positive and negative edge detection circuit 232 includes an input terminal and an output terminal. The input terminal of the pulse wave detection circuit 232 is electrically connected to the output terminal of the second differential amplifier 231.

The controller 24 is electrically connected to the control terminal of the first isolated gate driver 211a, the input terminal and the control terminal of the second isolated gate driver 211b, the output terminal of the overvoltage protection circuit 222, and the low voltage protection circuit The output terminal of 223, the output terminal of the pulse wave positive and negative edge detection circuit 224, the output terminal of the second differential amplifier 231, and the output terminal of the pulse wave positive and negative edge detection circuit 232.

The input terminal of the first isolated gate driver 211a receives the driving signal PWM_Q _W provided from the outside, and transmits it from the output terminal of the first isolated gate driver 211a to the control of the wide band gap power switch Q _W end, the wide band gap to control the power switch Q _W of the driving signal _V gs_QW transmitted during the wide-gap power switch Q _W of the first differential amplifier 221 to retrieve the driving signal _V gs_QW, The captured driving signal V _{gs_QW is} transmitted to the over-voltage protection circuit 222, the low-voltage protection circuit 223, and the pulse detection circuit 224. The over-voltage protection circuit 222 pre-stores an over-voltage standard value. When the over-voltage protection circuit 222 receives the captured driving signal V _{gs_QW} , a maximum voltage value of the driving signal V _{gs_QW} voltage is equal to the over-voltage standard value Compare and transmit the comparison result to the controller 24. The low voltage protection circuit 223 prestores a low voltage standard value. When the low voltage protection circuit 223 receives the captured driving signal V _{gs_QW} , a minimum voltage value of the driving signal V _{gs_QW} voltage is equal to the low voltage standard value Compare and transmit the comparison result to the controller 24. When the pulse positive and negative edge detection circuit 224 receives the captured driving signal V _{gs_QW} , it captures a positive edge signal at the instant _when the voltage of the driving signal V _{gs_QW changes} from a low level to a high level, and from a high level A negative edge signal at the moment when the bit becomes a low level, and the positive edge signal and the negative edge signal of the driving signal V _{gs_QW} are transmitted to the controller 24.

The controller 24 can determine whether the maximum voltage value and the minimum voltage value of the driving signal V _{gs_QW} voltage exceed the standard according to the comparison result transmitted from the over-voltage protection circuit 222 and the low-voltage protection circuit 223. In addition, the controller 24 internally when storing a corresponding frequency and a duty cycle, more by the positive edge of the signal of the driving signal _V gs_QW and the negative edge of the signal that the first operating frequency and changes the driving signal level is a first _V gs_QW Change the phase, and convert the stored frequency and the duty cycle into the correct value of the first phase corresponding to the first operating frequency and level change, so as to match the first operating frequency and the first operating frequency of the driving signal V _{gs_QW} The first phase comparison is used to determine whether the first phase of the driving signal V _{gs_QW} and the first operating frequency are abnormal. If the results meet the standard and there is no abnormality, the controller 24 generates the protection driving signal PWM_Q _P passed to the second input terminal of the isolated gate driver 211b, which protects the drive signal _V gs_QP then spread to a control terminal of the protection switch via the output terminal Q _p of the second isolated gate driver 211b of. If one of them exceeds the standard, the controller 24 sends out a fault notification signal S _fault and generates two interrupt signals S _int which are respectively transmitted to the control terminal of the first isolated gate driver 211a and the second isolated gate the control terminal of gate driver 211b of the first isolated gate driver 211a and the second isolated gate driver 211b occurs is turned off, the driving signal PWM_Q _{W W} isolated from the wide-gap power switch Q, and the protective a driving signal to the protective switching PWM_Q _P Q _P isolation.

It is worth mentioning that, the controller 24 generates the drive signal protection PWM_Q _P according to a cycle of the driving signal _V gs_QW of the driving signal _V gs_QP protection can be a single-cycle operation according to the drive signal, or more than one _V gs_QW Periodic operation. More specifically, the driving signal V _{gs_QW} is a square wave with the first operating frequency, the protection driving signal V _{gs_QP} is a square wave with the switching frequency, and the protection driving signal V _{gs_QP} operates in the single cycle At this time, a period of the protection driving signal V _{gs_QP} is equal to a period of the driving signal V _{gs_QW} , and a duty period of the driving signal V _{gs_QW} is smaller than a duty period of the protection driving signal V _{gs_QP} . When the protection driving signal V _{gs_QP} operates in the multiple cycles, one cycle of the protection driving signal V _{gs_QP} is equal to multiple and positive complete cycles of the driving signal V _{gs_QW} .

When the protection switch Q _P receives the protection drive signal V _{gs_QP} and switches to the on state, the protection switch Q _P forms a sensing resistance, and the wide band gap power switch Q _W starts to function, and then flows through the A sensing current of the wide band gap power switch Q _W is converted into a sensing voltage when flowing through the sensing resistor. The second differential amplifier 211b captures the sensing voltage and transmits it to the controller 24 and the current detection The pulse positive and negative edge detection circuit 232 of the unit 23, the pulse positive and negative edge detection circuit 232 captures the positive edge signal and the negative edge signal of the sensing voltage, and combines the positive edge signal of the sensing voltage The negative edge signal is transmitted to the controller 24. The controller 24 can determine whether the sensing current exceeds the standard for overcurrent protection based on the sensing voltage. In addition, the controller 24 can perform overcurrent protection based on the positive value of the sensing voltage. The edge signal and the negative edge signal learn the changes of a second operating frequency and a second phase of the sensing voltage, and determine whether the second phase and the second operating frequency of the sensing voltage are abnormal, the same If one of them exceeds the standard, the controller 24 sends the fault notification signal S _{fault to the} outside, and generates the interrupt signals S _{int to be} respectively sent to the first isolated gate driver 211a and the second isolated gate Pole driver 211b.

It should be added that the driving signal PWM_Q _W can be directly transmitted from the first isolated gate driver 211a to the control terminal of the wide band gap power switch Q _W , so that the path in the circuit is minimized and electromagnetic interference is minimized. In order to prevent the internal parasitic capacitance and parasitic inductance of the protection switch Q _P from affecting the conduction state and non-conduction state of the wide band gap power switch Q _W , the driving signal PWM_Q _W and the protection driving signal PWM_Q _P respectively pass through the first isolation type gate driver 211a and the second isolated gate driver 211b then pass the wide band gap power switch control terminal Q _W control terminal of the protective switch Q _P so that the driving signal _V gs_QW and the guard driving signal V _{gs_QP is} not susceptible to noise interference on the ground path.

Therefore, the protection device 2 can detect whether the voltage range of the driving signal V _{gs_QW} exceeds the standard, whether the first phase of the driving signal V _{gs_QW} and the first operating frequency are abnormal, and whether the current of the sensing current There is an overcurrent phenomenon, and whether the second phase of the sensing voltage converted by the sensing current and the second operating frequency are abnormal. If any error or abnormality is detected, the wide band gap power switch is controlled When Q _{W is} turned off, damage to the wide band gap power switch Q _W during use can be avoided.

With reference to the second and third figures, the power module M with a wide band gap power switch of the present invention is applied to a single-phase synchronous rectification and buck converter, which includes an input power supply V _in , an upper bridge power module M_QH, a lower bridge power module M_QL, an energy storage inductor L ₁ , an output capacitor C _o , a Zener diode Z _D , and a load Load.

The wide-gap power on the first end of the bridge power module M_QH switch Q _W terminal is connected to the positive supply V _in is input, the second end of the bridge power module M_QH the protective switch is connected to Q _P the wide-gap power of the power module M_QL bridge the lower end of the first switch Q _W, and the negative terminal of the zener diode Z _D is, and the first end of the inductor L ₁ of the lower die bridge power the negative terminal second end of the protective switch M_QL set Q _P is connected to the input of the power supply V _in, and the positive terminal of the zener diode Z _D, and the output capacitor C _o is electrically connected to the positive terminal of the inductor a first terminal and a second terminal L of the load load _1, the negative terminal of the output capacitor C _o is electrically connected to the positive terminal of the zener Z _D and the load terminal load of a second polar body.

Externally input two drive signals PWM _H and PWM _L to the protection device 2 of the upper-bridge power module M_QH and the protection device 2 of the lower-bridge power module M_QL respectively. The drive signals PWM _H and PWM _L are complementary signals. The protection drive signal V _{gs2 of the} upper bridge power module M_QH operates in the multi-cycle operation, and the protection drive signal V _{gs4 of} the lower bridge power module _{M_QL} operates in the single cycle operation. In this example, the upper bridge power One period of the protection driving signal V _gs2 of the module M_QH is set equal to four periods of the driving signal V _gs1 .

In the interval from time t ₀ to t ₁ , the driving signal V _gs1 and the protection driving signal V _gs2 turn on the wide band gap power switch Q _{W of} the upper bridge power module M_QH and the protection switch Q _P , and the driving signal V _gs3 , The protection drive signal V _gs4 makes the wide band gap power switch Q _{W of} the lower bridge power module M_QL and the protection switch Q _P cut off, then the input voltage V _in , the upper bridge power module M_QH, the energy storage inductor L ₁ and the output capacitor C _o form a charging loop, and an energy storage current i _{L1 (charge)} flowing through the energy storage inductor L ₁ makes the energy storage inductor L ₁ perform energy storage, in the interval from time t ₁ to t ₂ , The wide band gap power switch Q _{W of} the upper bridge power module M_QH is turned off, the protection switch Q _{P is} turned on, the wide band gap power switch Q _{W of} the lower bridge power module M_QL is turned on, and the protection switch Q _P is still turned off, The energy storage inductor L ₁ forms a discharge loop through the Zener diode Z _D , and a discharge current i _{L1 (discharge)} flowing from the energy storage inductor L ₁ causes the energy storage inductor L ₁ to temporarily _discharge energy. After repeating three cycles in this way, in the interval from time t ₃ to t ₄ , the wide band gap power switch Q _{W of} the upper bridge power module M_QH and the protection switch Q _{P are} turned off, and the protection switch of the lower bridge power module M_QL Q _P and the wide band gap power switch Q _{W are} turned on successively, so that the energy storage inductor L ₁ discharges energy for a long time, and finally reaches a volt-second balance. If the protection circuit 2 of the upper bridge power module M_QH detects an abnormality in any of the current, voltage, phase and operating frequency in the first cycle, the wide band gap power switch Q of the upper bridge power module M_QH _W. The protection switch Q _{P is} immediately turned off and the fault notification signal is generated externally; if the protection circuit 2 of the lower bridge power module M_QL detects an abnormality in any of the current, voltage, phase, and operating frequency, the The wide band gap power switch Q _W and the protection switch Q _{P of the} lower bridge power module M_QH are also immediately turned off, and the fault notification signal is generated externally, and the Zener diode Z _D will perform a flywheel mode The current of the energy storage inductor L ₁ is zero. Therefore, with the detection and protection of the protection device 2 of the upper bridge power module M_QH and the protection device 2 of the lower bridge power module M_QH, the wide band gap power switch Q _{W of} the upper bridge power module M_QH and the The wide band gap power switch Q _{W of the} lower bridge power module M_QL can avoid damage.

In summary, the protection device 2 can detect whether the voltage range of the driving signal V _{gs_QW} input to the wide band gap power switch Q _W exceeds the standard, the first phase and the second phase of the driving signal V _{gs_QW} Whether an operating frequency is abnormal, whether the sensing current of the wide band gap power switch Q _W has an overcurrent phenomenon, and whether the sensing current is converted into the second phase of the sensing voltage and the second operation Whether the frequency is abnormal, if any error or abnormality is detected, the wide band gap power switch Q _W is controlled to be turned off, which can avoid the damage of the wide band gap power switch Q _W during use, so as to protect the wide band gap The efficiency of the band gap power switch Q _W is also directly transmitted from the first isolated gate driver 211a to the control terminal of the wide band gap power switch Q _W by the driving signal V _{gs_QW} , so that electromagnetic interference is minimized, To prevent the internal parasitic capacitance and parasitic inductance of the protection switch Q _P from affecting the conduction state and non-conduction state of the wide band gap power switch Q _W , the driving signal PWM_Q _W and the protection driving signal PWM_Q _P respectively pass through the first The isolated gate driver 211a and the second isolated gate driver 211b are then transmitted to the wide band gap power switch Q _W and the protection switch Q _P , so that the driving signal V _{gs_QW} and the protection driving signal V _{gs_QP are} not easily affected. The noise interference on the ground path can indeed achieve the purpose of the invention.

Based on the description of the above-mentioned embodiments, when one can fully understand the operation and use of the present invention and the effects of the present invention, the above-mentioned embodiments are only preferred embodiments of the present invention, and the implementation of the present invention cannot be limited by this. The scope, that is, simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the description of the invention, are all within the scope of the present invention.

(2): Protection device

(21): Isolated drive unit

(211): Isolated gate driver

(211a): The first isolated gate driver

(211b):Second isolated gate driver

(22): Voltage detection unit

(221): First differential amplifier

(222): Overvoltage protection circuit

(223): Low voltage protection circuit

(224): Pulse positive and negative edge detection circuit

(23): Current detection unit

(231): Second differential amplifier

(232): Pulse positive and negative edge detection circuit

(24): Controller

(M): Power module

(Q _W ): Wide band gap power switch

(Q _P ): Protection switch

(V _{gs_QW} ): drive signal

(V _{gs_QP} ): Protect drive signal

(PWM_Q _W ): drive signal

(PWM_Q _P ): Protect drive signal

(S _fault ): fault notification signal

(S _int ): Interrupt signal

(V _CC1 ): Input power

(V _CC2 ): Input power

(V _CC3 ): Input power

Claims (6)

A power module with a wide band gap power switch, receiving a driving signal, and comprising: a wide band gap power switch capable of receiving the driving signal, and switching between a conducting state and a non-conducting state according to the driving signal; The protection switch is electrically connected to the wide bandgap power switch, and the protection switch receives a protection drive signal and switches between the conducting state and the non-conducting state according to the control of the protection drive signal, when the protection switch is switched in the conducting state , The wide band gap power switch starts to work; and a protection device that generates the protection drive signal according to a period of the drive signal, and the protection device detects whether a maximum voltage value and a minimum voltage value of the drive signal exceed the standard If the protection device detects that one of the maximum voltage value and the minimum voltage value exceeds the standard, the protection device immediately controls the drive signal to be isolated from the wide band gap power switch, and controls the protection drive signal and the protection The switch is isolated, and the protection device detects whether a first phase and a first operating frequency of the drive signal are abnormal. When the protection switch is turned on, the protection device detects that the wide band gap power switch flows through the protection Whether a sensing current of the switch exceeds the standard, and converting the sensing current into a sensing voltage, and detecting whether a second phase of the sensing voltage and a second operating frequency are abnormal, if the protection device detects When one of the first phase, the first operating frequency, the sensing current, the second phase, and the second operating frequency exceeds the standard or is abnormal, the protection device immediately controls the driving signal and the wide-energy The gap power switch is isolated, and the protection drive signal is controlled to be isolated from the protection switch. The wide band gap power switch includes a first end, a second end, and a control end. The protection switch includes a first end, A second end and a control end. The first end of the protection switch is electrically connected to the second end of the wide bandgap power switch. The protection device includes an isolated drive unit, a voltage detection unit, and a current detection Unit, and a controller, the isolated drive unit is electrically connected to the control terminal of the wide band gap power switch and the protection switch Control terminal, the voltage detection unit is electrically connected to the isolated drive unit, the current detection unit is electrically connected to the second end of the protection switch, and the controller is electrically connected to the isolated drive unit, the voltage detection unit and the current Detection unit, the driving signal is transmitted to the wide band gap power switch through the isolation driving unit, the protection driving signal generated by the controller is transmitted to the protection switch through the isolation driving unit, and the driving signal is transmitted to the In the process of wide-bandgap power switching, the voltage detection unit captures the drive signal, detects whether the maximum voltage value and the minimum voltage value of the drive signal exceed their respective standards, and captures the drive signal A positive edge signal and a negative edge signal, and the result and the captured positive edge signal and negative edge signal are transmitted to the controller. When the protection switch is turned on, the current detection unit captures the sensing voltage A positive edge signal and a negative edge signal of the drive signal, and the sensing voltage and the captured positive edge signal and the negative edge signal are transmitted to the controller, and the controller is based on the positive edge signal and the positive edge signal of the driving signal The negative edge signal determines whether the first phase of the driving signal and the first operating frequency are abnormal, and the second phase and the second phase of the sensing voltage are determined according to the positive edge signal and the negative edge signal of the sensing voltage. Whether the second operating frequency is abnormal, and determine whether the sensing current exceeds the standard based on the sensing voltage, if the controller receives any wrong result or judges any error or abnormality, it can control the isolated drive unit to occur End, and generate a fault notification signal. The power module with a wide bandgap power switch as described in claim 1 of the scope of patent application, wherein the voltage detection unit includes a first differential amplifier, an over-voltage protection circuit, a low-voltage protection circuit, and a The pulse wave positive and negative edge detection circuit, the first differential amplifier is electrically connected to the isolated drive unit, the overvoltage protection circuit is electrically connected to the first differential amplifier and the controller, and the low voltage protection circuit is electrically connected to the first A differential amplifier and the controller. The pulse wave positive and negative edge detection circuit is electrically connected to the first differential amplifier and the controller. The first differential amplifier captures the drive signal and transmits the captured drive signal To the over-voltage protection circuit, the low-voltage protection circuit, and the pulse wave positive and negative edge detection circuit, The over-voltage protection circuit detects whether the maximum voltage value of the driving signal exceeds the standard, and transmits the result to the controller, the low-voltage protection circuit detects whether the minimum voltage value of the driving signal exceeds the standard, and sends the result The pulse wave positive-negative edge detection circuit captures the positive-edge signal and the negative-edge signal of the driving signal and transmits them to the controller. The power module with a wide bandgap power switch as described in claim 1, wherein the current detection unit includes a second differential amplifier and a pulse wave positive and negative edge detection circuit, the second difference The active amplifier is electrically connected to the second end of the protection switch and the controller. The pulse wave positive and negative edge detection circuit is electrically connected to the second differential amplifier and the controller. When the protection switch is turned on, the protection switch forms a sensor. Measuring resistance, the sensing current flowing through the sensing resistance is converted into the sensing voltage, the second differential amplifier captures the sensing voltage and transmits it to the controller and the pulse wave positive and negative edge detection circuit, the pulse wave The positive and negative edge detection circuit captures the positive edge signal and the negative edge signal of the sensing voltage, and transmits the positive edge signal and the negative edge signal of the sensing voltage to the controller. The power module with a wide band gap power switch as described in item 1 of the scope of patent application, wherein the wide band gap power switch is an enhanced gallium nitride transistor, and the protection switch is a silicon metal oxide half field effect Transistor. The power module with a wide bandgap power switch as described in item 1 of the scope of patent application, wherein the drive signal is a square wave with a first operating frequency, and the protection drive signal is a square wave with a switching frequency, A period of the protection driving signal is equal to a period of the driving signal, and a duty period of the driving signal is smaller than a duty period of the protection driving signal. The power module with a wide bandgap power switch as described in item 1 of the scope of patent application, wherein the drive signal is a square wave with a first operating frequency, and the protection drive signal is a square wave with a switching frequency, One period of the protection driving signal is equal to multiple and positive complete periods of the driving signal.

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