Gallium nitride device driving circuit

Abstract

The utility model discloses a gallium nitride device driving circuit. The gallium nitride device driving circuit comprises a driving module, a current detection module, a power supply adjusting module and a power supply module, the driving module is connected with a control electrode of the gallium nitride device, and the driving module is configured to output driving voltage to the gallium nitride device; the power end of the driving module is connected with the output end of the power module; the current detection module is connected with a first pole of the gallium nitride device, and the current detection module is configured to detect an actual current value of the gallium nitride device; the power supply adjusting module is connected with the current detection module, the power supply adjusting module is connected with the output end and the adjusting end of the power supply module, and the power supply adjusting module is configured to adjust the output voltage of the power supply module when the actual voltage value corresponding to the actual current value is larger than the reference voltage. According to the gallium nitride device driving circuit, the problem that the heating failure is easy to occur when the actual current value of the gallium nitride device is relatively large can be avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of drive circuits, in particular to a drive circuit for gallium nitride devices. Background Art

[0002] Gallium nitride devices include gallium nitride transistors. Gallium nitride transistors are widely used due to their high electron mobility characteristics.

[0003] The controller outputs a pulse width modulation (PWM) signal to the driver. When the PWM signal is at a high level, the driver provides a high-level drive voltage to the gallium nitride transistor, causing the gallium nitride transistor to turn on. When the PWM signal is at a low level, the driver provides a low-level drive voltage to the gallium nitride transistor, causing the gallium nitride transistor to turn off.

[0004] The power supply module supplies power to the driver. However, the power supply voltage provided by the power supply module to the driver is a fixed voltage, so that the high-level drive voltage output by the driver is a fixed voltage, and thus the saturation current value of the gallium nitride device is fixed. When the current of the gallium nitride device increases to the saturation current value, it is prone to heat and failure. Summary of the Utility Model

[0005] The utility model provides a drive circuit for gallium nitride devices to solve the problem that gallium nitride devices are prone to heat and failure.

[0006] The utility model provides a drive circuit for gallium nitride devices, which includes: a drive module, a current detection module, a power supply adjustment module, and a power supply module;

[0007] The drive module is connected to the control electrode of the gallium nitride device, and the drive module is configured to output a drive voltage to the gallium nitride device; the power supply terminal of the drive module is connected to the output terminal of the power supply module;

[0008] The current detection module is connected to the first electrode of the gallium nitride device, and the current detection module is configured to detect the actual current value of the gallium nitride device;

[0009] The power supply adjustment module is connected to the current detection module. The power supply adjustment module is respectively connected to the output terminal and the adjustment terminal of the power supply module. The power supply adjustment module is configured to adjust the output voltage of the power supply module when the actual voltage value corresponding to the actual current value is greater than the reference voltage.

[0010] Optionally, the power supply adjustment module includes a comparison unit and a power supply adjustment unit;

[0011] The first input terminal of the comparison unit is connected to the current detection module, the second input terminal of the comparison unit is connected to the reference voltage, the output terminal of the comparison unit is connected to the power supply adjustment unit, and the comparison unit is configured to send a trigger signal to the power supply adjustment unit when the actual voltage value corresponding to the actual current value is greater than the reference voltage;

[0012] The power supply adjustment unit is respectively connected to the output terminal and the adjustment terminal of the power supply module, and the power supply adjustment unit is configured to adjust the output voltage of the power supply module in response to the trigger signal.

[0013] Optionally, the power supply adjustment unit includes a timing sub-unit and a power supply adjustment sub-unit;

[0014] The trigger terminal of the timing sub-unit is connected to the output terminal of the comparison unit, and the output terminal of the timing sub-unit is connected to the control terminal of the power supply adjustment sub-unit; the timing sub-unit is configured to send a turn-off signal with a preset duration to the power supply adjustment sub-unit in response to the trigger signal, and send a conduction signal to the power supply adjustment sub-unit when the trigger signal is not received;

[0015] The power supply adjustment sub-unit is respectively connected to the output terminal and the adjustment terminal of the power supply module, and the power supply adjustment sub-unit is configured to adjust the output voltage of the power supply module to the initial voltage according to the conduction signal, or adjust the output voltage of the power supply module to the target voltage according to the turn-off signal; wherein, the target voltage is greater than the initial voltage.

[0016] Optionally, the timing sub-unit includes a timer, a first resistor, a second resistor and a first capacitor;

[0017] The trigger terminal of the timer is electrically connected to the output terminal of the comparison unit; the output terminal of the timer is connected to the control terminal of the power supply adjustment sub-unit;

[0018] The power supply terminal of the timer is electrically connected to the first end of the first resistor, and the second end of the first resistor is grounded through the first capacitor;

[0019] The timing terminal of the timer is electrically connected to the second end of the first resistor;

[0020] The second resistor is connected between the power supply terminal of the timer and the output terminal of the timer.

[0021] Optionally, the power supply adjustment sub-unit includes a switching transistor, a third resistor, a fourth resistor, a fifth resistor and a sixth resistor;

[0022] The control electrode of the switching transistor is electrically connected to the output terminal of the timing sub-unit, and the first pole of the switching transistor is grounded;

[0023] The third resistor is connected between the control electrode of the switching transistor and the first electrode of the switching transistor;

[0024] The first end of the fourth resistor is electrically connected to the output end of the power supply module, the second end of the fourth resistor is electrically connected to the first end of the fifth resistor, and the second end of the fifth resistor is grounded;

[0025] The sixth resistor is connected between the second electrode of the switching transistor and the adjustment end of the power supply module.

[0026] Optionally, the preset duration is greater than the duration of a single conduction of the gallium nitride device.

[0027] Optionally, the driving module includes a driver, a first driving resistor, and a second driving resistor;

[0028] The first power supply terminal of the driver is connected to the output end of the power supply module, the second power supply terminal of the driver is grounded, the input terminal of the driver receives a control signal, the first output terminal of the driver is connected to the control electrode of the gallium nitride device through the first driving resistor, and the second output terminal of the driver is connected to the control electrode of the gallium nitride device through the second driving resistor; the driver is configured to transmit a driving voltage of a first level to the gallium nitride device through the first driving resistor, or transmit a driving voltage of a second level to the gallium nitride device through the second driving resistor.

[0029] Optionally, the comparison unit includes a comparator;

[0030] The first input terminal of the comparator is electrically connected to the current detection module, the second input terminal of the comparator receives the reference voltage, and the output terminal of the comparator is connected to the power supply adjustment unit.

[0031] Optionally, the power supply module includes an adjustable power supply chip.

[0032] Optionally, the gallium nitride device driving circuit further includes a controller;

[0033] The controller is connected to the input terminal of the driving module, the controller is configured to transmit a control signal to the driving module, and the driving module is configured to transmit a driving voltage to the control electrode of the gallium nitride device according to the control signal.

[0034] In the technical solution of the embodiment of the present utility model, the gallium nitride device driving circuit includes: a driving module, a current detection module, a power supply regulation module, and a power supply module. The current detection module can collect the actual current value of the gallium nitride device in real time or periodically, and convert the actual current value into an actual voltage value. The power supply regulation module can compare the actual voltage value with a reference voltage. When the actual voltage value is less than or equal to the reference voltage, the power supply regulation module can not adjust the output voltage of the power supply module, and the power supply module maintains the output of the initial voltage, that is, the power supply terminal of the driving module is connected to the initial voltage. When the actual voltage value is greater than the reference voltage, the power supply regulation module adjusts the output voltage of the power supply module, for example, increases the output voltage of the power supply module, so that the power supply voltage of the driving module increases, thereby increasing the driving voltage output by the driving module, improving the channel ability of the gallium nitride device, and further increasing the saturation current ability of the gallium nitride device, making it not easy for the gallium nitride device to reach the saturation current value, and avoiding the problem of easy heat generation failure when the actual current value of the gallium nitride device is large.

[0035] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present utility model, nor is it used to limit the scope of the present utility model. Other features of the present utility model will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0037] Figure 1 is a schematic structural diagram of a gallium nitride device driving circuit provided by an embodiment of the present utility model;

[0038] Figure 2 is a schematic structural diagram of another gallium nitride device driving circuit provided by an embodiment of the present utility model;

[0039] Figure 3 is a schematic structural diagram of another gallium nitride device driving circuit provided by an embodiment of the present utility model;

[0040] Figure 4 is a schematic structural diagram of another gallium nitride device driving circuit provided by an embodiment of the present utility model;

[0041] Figure 5 is a driving timing diagram of a gallium nitride device provided by an embodiment of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0042] To enable those skilled in the art to better understand the solution of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0043] It should be noted that the terms "first", "second", etc. in the description and claims of the present utility model and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present utility model described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0044] Aiming at the problem that gallium nitride devices are prone to heat generation and failure, this embodiment provides a gallium nitride device drive circuit. The gallium nitride device includes a gallium nitride transistor. Figure 1 It is a schematic structural diagram of a gallium nitride device drive circuit provided by an embodiment of the present utility model. Refer to Figure 1 , the gallium nitride device drive circuit includes: a drive module 10, a current detection module 20, a power supply adjustment module 30, and a power supply module 40;

[0045] The drive module 10 is connected to the control electrode of the gallium nitride device 50, and the drive module 10 is configured to output a drive voltage to the gallium nitride device 50; the power supply terminal of the drive module 10 is connected to the output terminal OUT of the power supply module 40;

[0046] The current detection module 20 is connected to the first electrode of the gallium nitride device 50, and the current detection module 20 is configured to detect the actual current value of the gallium nitride device 50;

[0047] The power supply adjustment module 30 is connected to the current detection module 20. The power supply adjustment module 30 is respectively connected to the output terminal OUT and the adjustment terminal ADJ of the power supply module 40. The power supply adjustment module 30 is configured to adjust the output voltage of the power supply module 40 when the actual voltage value corresponding to the actual current value is greater than the reference voltage.

[0048] Among them, the driving module 10 may include a driver or a driving circuit, which is not limited in this embodiment. The driving module 10 can output a driving voltage to the control electrode of the gallium nitride device 50 according to a control signal, and the control signal is, for example, a pulse width modulation signal. When the pulse width modulation signal is at the first level, the driving module 10 outputs a driving voltage at the first level to the control electrode of the gallium nitride device 50, and the gallium nitride device 50 conducts forward. When the pulse width modulation signal is at the second level, the driving module 10 outputs a driving voltage at the second level to the control electrode of the gallium nitride device 50, so that the gallium nitride device 50 is turned off. Among them, for example, the first level is a high level and the second level is a low level; or the first level is a low level and the second level is a high level, which is not limited in this embodiment.

[0049] The current detection module 20 can be connected between the first electrode of the gallium nitride device 50 and the power ground. The second electrode of the gallium nitride device 50 can be connected to a load or other circuits, which is not limited in this embodiment. Among them, the control electrode of the gallium nitride device 50 is the gate. For example, the first electrode of the gallium nitride device 50 is the source electrode and the second electrode of the gallium nitride device 50 is the drain electrode; or the first electrode of the gallium nitride device 50 is the drain electrode and the second electrode of the gallium nitride device 50 is the source electrode. The current detection module 20 can be a current sensor, a current transformer, an ammeter, a sampling resistor, etc., which is not limited in this embodiment. The current detection module 20 can collect the actual current value between the first electrode and the second electrode of the gallium nitride device 50 and convert the actual current value into an actual voltage value and send it to the power supply adjustment module 30.

[0050] The power supply module 40 includes an adjustable power supply, that is, the output voltage of the power supply module 40 is adjustable. For example, the power supply module 40 includes an adjustable low dropout regulator (LDO). The power supply module 40 supplies power to the driving module 10.

[0051] Specifically, the current detection module 20 can collect the actual current value of the gallium nitride device 50 in real time or periodically and convert the actual current value into an actual voltage value. The power supply adjustment module 30 can compare the actual voltage value with a reference voltage. When the actual voltage value is less than or equal to the reference voltage, the power supply adjustment module 30 can not adjust the output voltage of the power supply module 40, and the power supply module 40 maintains the output initial voltage, that is, the power supply terminal of the driving module 10 is connected to the initial voltage. When the actual voltage value is greater than the reference voltage, the power supply adjustment module 30 adjusts the output voltage of the power supply module 40, for example, increases the output voltage of the power supply module 40.

[0052] Among them, the reference voltage is the voltage corresponding to the saturation current under the normal driving voltage. When the actual voltage value is greater than the reference voltage, it indicates that the actual current value of the gallium nitride device 50 reaches the saturation current value, that is, reaches the current limit value, and is prone to heat failure. When the actual voltage value is greater than the reference voltage, by increasing the output voltage of the power supply module 40, the power supply voltage of the driving module 10 is increased, so as to increase the driving voltage output by the driving module 10, improve the channel ability of the gallium nitride device 50, and further increase the saturation current ability of the gallium nitride device 50, so that the gallium nitride device 50 is not easily saturated. The current value avoids the problem of easy heat failure when the actual current value of the gallium nitride device 50 is large.

[0053] In the technical solution of this embodiment, the gallium nitride device driving circuit includes: a driving module, a current detection module, a power supply adjustment module, and a power supply module. The current detection module can collect the actual current value of the gallium nitride device in real time or periodically, and convert the actual current value into an actual voltage value. The power supply adjustment module can compare the actual voltage value with the reference voltage. When the actual voltage value is less than or equal to the reference voltage, the power supply adjustment module can not adjust the output voltage of the power supply module, and the power supply module maintains the output of the initial voltage, that is, the power supply terminal of the driving module is connected to the initial voltage. When the actual voltage value is greater than the reference voltage, the power supply adjustment module adjusts the output voltage of the power supply module. For example, by increasing the output voltage of the power supply module, the power supply voltage of the driving module is increased, so as to increase the driving voltage output by the driving module, improve the channel ability of the gallium nitride device, and further increase the saturation current ability of the gallium nitride device, so that the gallium nitride device is not easily saturated. The current value avoids the problem of easy heat failure when the actual current value of the gallium nitride device is large.

[0054] Based on the above technical solution, Figure 2 is a schematic structural diagram of another gallium nitride device driving circuit provided by an embodiment of the present invention. Optionally, refer to Figure 2 , the power supply adjustment module 30 includes a comparison unit 310 and a power supply adjustment unit 320;

[0055] The first input end of the comparison unit 310 is connected to the current detection module 20, the second input end of the comparison unit 310 is connected to the reference voltage Vref, the output end of the comparison unit 310 is connected to the power supply adjustment unit 320, and the comparison unit 310 is configured to send a trigger signal to the power supply adjustment unit 320 when the actual voltage value corresponding to the actual current value is greater than the reference voltage Vref;

[0056] The power supply adjustment unit 320 is respectively connected to the output end OUT and the adjustment end ADJ of the power supply module 40, and the power supply adjustment unit 320 is configured to adjust the output voltage of the power supply module 40 in response to the trigger signal.

[0057] Among them, for example, the first input terminal of the comparison unit 310 is an inverting input terminal, and the second input terminal of the comparison unit 310 is a non-inverting input terminal; or the first input terminal of the comparison unit 310 is a non-inverting input terminal, and the second input terminal of the comparison unit 310 is an inverting input terminal. This embodiment does not make a limitation.

[0058] Specifically, the comparison unit 310 can compare the actual voltage value corresponding to the actual current value of the gallium nitride device 50 with the reference voltage. When the actual voltage value is less than or equal to the reference voltage, no trigger signal is sent to the power supply adjustment unit 320. When the actual voltage value is greater than the reference voltage, a trigger signal is sent to the power supply adjustment unit 320. Therefore, a trigger signal can be sent to the power supply adjustment unit 320 when the actual current value is relatively large. After receiving the trigger signal, the power supply adjustment unit 320 can adjust the output voltage of the power supply module 40, for example, increase the output voltage of the power supply module 40, so as to increase the power supply voltage of the driving module 10, increase the driving voltage output by the driving module 10, and enhance the saturation current capacity of the gallium nitride device 50.

[0059] Optionally, referring to Figure 2 , the power supply adjustment unit 320 includes a timing subunit 321 and a power supply adjustment subunit 322;

[0060] The trigger terminal of the timing subunit 321 is connected to the output terminal of the comparison unit 310, and the output terminal of the timing subunit 321 is connected to the control terminal of the power supply adjustment subunit 322; the timing subunit 321 is configured to send a turn-off signal with a preset duration to the power supply adjustment subunit 322 in response to the trigger signal, and send a conduction signal to the power supply adjustment subunit 322 when no trigger signal is received;

[0061] The power supply adjustment subunit 322 is respectively connected to the output terminal OUT and the adjustment terminal ADJ of the power supply module 40, and the power supply adjustment subunit 322 is configured to adjust the output voltage of the power supply module 40 to the initial voltage according to the conduction signal, or adjust the output voltage of the power supply module 40 to the target voltage according to the turn-off signal; wherein, the target voltage is greater than the initial voltage.

[0062] Among them, the timing subunit 321 can include a timer or a delay circuit.

[0063] Specifically, when the actual voltage value is less than or equal to the reference voltage, the comparison unit 310 does not send a trigger signal to the timing sub-unit 321, and can send a signal with a different level from the trigger signal to the timing sub-unit 321. When the trigger signal is at a low level, a high-level signal can be sent to the timing sub-unit 321; when the trigger signal is at a high level, a low-level signal can be sent to the timing sub-unit 321. When the timing sub-unit 321 does not receive the trigger signal, it sends a conduction signal to the power supply regulation sub-unit 322, and the power supply regulation sub-unit 322 maintains the output voltage of the power supply module 40 at the initial voltage.

[0064] When the actual voltage value is greater than the reference voltage, the comparison unit 310 sends a trigger signal to the timing sub-unit 321. The timing sub-unit 321 sends a turn-off signal to the power supply regulation sub-unit 322 and starts timing until the turn-off signal is sent for a preset duration. After the power supply regulation sub-unit 322 receives the turn-off signal, it increases the output voltage of the power supply module 40 so that the output voltage of the power supply module 40 reaches the target voltage, thereby increasing the voltage at the power supply terminal of the driving module 10.

[0065] Based on the above technical solution, Figure 3 is a schematic structural diagram of another gallium nitride device driving circuit provided by an embodiment of the present invention. Optionally, refer to Figure 3 , the timing sub-unit 321 includes a timer U1, a first resistor R1, a second resistor R2, and a first capacitor C1;

[0066] The trigger terminal of the timer U1 is electrically connected to the output terminal of the comparison unit 310; the output terminal of the timer U1 is connected to the control terminal of the power supply regulation sub-unit 322;

[0067] The power supply terminal of the timer U1 is connected to the first power supply VCC;

[0068] The power supply terminal of the timer U1 is electrically connected to the first end of the first resistor R1, and the second end of the first resistor R1 is grounded through the first capacitor C1 to GND;

[0069] The timing terminal of the timer U1 is electrically connected to the second end of the first resistor R1;

[0070] The second resistor R2 is connected between the power supply terminal of the timer U1 and the output terminal of the timer U1.

[0071] Among them, the power supply terminal of the timer U1 is connected to the first power supply VCC, and the first power supply VCC can be provided by an external power supply device. The ground connected to the first capacitor C1 is the power ground.

[0072] Specifically, by adjusting the resistance value of the first resistor R1 and / or the capacitance value of the first capacitor C1, the timing duration of the timer U1 can be adjusted, so that the timer U1 outputs a turn-off signal with a preset duration. By setting the second resistor R2, it is convenient for the output terminal of the timer U1 to output a high-level signal.

[0073] Exemplarily, the timer U1 can be a 555 timer. For example, the trigger terminal of the timer U1 is a low-level trigger terminal, the high trigger terminal of the timer U1, and the high trigger terminal of the timer U1 is electrically connected to the second terminal of the first resistor R1. The timing terminal of the timer U1 is a discharge terminal. By setting the first resistor R1 and the first capacitor C1, the discharge time of the capacitor in the timer U1 can be adjusted, thereby adjusting the timing duration.

[0074] Optionally, referring to Figure 3 , the power supply adjustment sub-unit 322 includes a switching transistor Q1, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6;

[0075] The control electrode of the switching transistor Q1 is electrically connected to the output terminal of the timing sub-unit 321, and the first electrode of the switching transistor Q1 is grounded to GND;

[0076] The third resistor R3 is connected between the control electrode of the switching transistor Q1 and the first electrode of the switching transistor Q1;

[0077] The first terminal of the fourth resistor R4 is electrically connected to the output terminal of the power supply module 40, the second terminal of the fourth resistor R4 is electrically connected to the first terminal of the fifth resistor R5, and the second terminal of the fifth resistor R5 is grounded to GND;

[0078] The sixth resistor R6 is connected between the second electrode of the switching transistor Q1 and the adjustment terminal ADJ of the power supply module 40.

[0079] Wherein, the first electrode of the switching transistor Q1 and the second terminal of the fifth resistor R5 are connected to the power supply ground GND.

[0080] Specifically, when the timing subunit 321 does not receive a trigger signal, it sends a conduction signal to the switching transistor Q1, and the switching transistor Q1 conducts, enabling the sixth resistor R6 to be connected to the circuit. Then, after the sixth resistor R6 and the fifth resistor R5 are connected in parallel and then connected in series with the fourth resistor R4, the power supply module 40 outputs a smaller initial voltage. After the timing subunit 321 receives the trigger signal, it sends a turn-off signal to the switching transistor Q1, and the switching transistor Q1 turns off, causing the sixth resistor R6 not to be connected to the circuit. The fifth resistor R5 is directly connected in series with the fourth resistor R4, making the resistance value in the circuit larger, and the power supply module 40 outputs a larger target voltage. In this way, the output voltage of the power supply module 40 is increased, thereby increasing the power supply voltage of the drive module 10, further increasing the drive voltage output by the drive module 10, increasing the voltage of the control electrode of the gallium nitride device 50, enhancing the saturation current capacity of the gallium nitride device 50, and making it difficult for the gallium nitride device 50 to reach the saturation current, so it is not easy to heat and fail.

[0081] Exemplarily, the voltage of the adjustment terminal ADJ of the power supply module 40 is the reference voltage V of the power supply module 40 r , and the reference voltage of the power supply module 40 can be fixed. For example, the output voltage of the output terminal OUT of the power supply module 40 is V out , the resistance value of the fourth resistor R4 is R4, the resistance value of the fifth resistor R5 is R5, and the resistance value of the sixth resistor R6 is R6. Then, when the switching transistor Q1 conducts, the output voltage of the output terminal OUT of the power supply module 40 is When the switching transistor Q1 is turned off, the output voltage of the output terminal OUT of the power supply module 40 is Therefore, after the switching transistor Q1 is turned off, the output voltage of the output terminal OUT of the power supply module 40 increases.

[0082] Optionally, the preset duration is greater than the duration of a single conduction of the gallium nitride device 50.

[0083] Among them, the drive module 10 can output a drive voltage according to a control signal, and the control signal is a pulse width modulation signal. When the control signal is at a high level, the drive module 10 outputs a high-level drive voltage to the gallium nitride device 50. When the control signal is at a low level, the drive module 10 outputs a low-level drive voltage to the gallium nitride device 50. The gallium nitride device 50 responds to the low-level or high-level drive voltage to conduct, so the duration of a single conduction of the gallium nitride device 50 can be the duration of a single high level or a single low level of the pulse width adjustment signal.

[0084] Specifically, after the gallium nitride device 50 is turned on, the current of the gallium nitride device 50 gradually increases. After the next turn-on, it gradually increases again from a relatively small current value (e.g., 0). By setting the preset duration to be greater than the single turn-on duration of the gallium nitride device 50, it can be ensured that the duration for enhancing the saturation ability of the gallium nitride device 50 is greater than the duration for the current increase of the gallium nitride device 50. Thus, it can be ensured that the duration for enhancing the saturation ability of the gallium nitride device 50 is greater than the duration during which the actual voltage value corresponding to the actual current value of the gallium nitride device 50 is greater than the reference voltage. Furthermore, it can be ensured that the actual current value of the gallium nitride device 50 does not reach the saturation current limit value, so that it will not heat up and fail.

[0085] Optionally, referring to Figure 3 , the driving module 10 includes a driver U2, a first driving resistor Ron, and a second driving resistor Roff;

[0086] The first power supply terminal of the driver U2 is connected to the output terminal OUT of the power supply module 40. The second power supply terminal of the driver U2 is grounded. The input terminal of the driver U2 receives a control signal P1. The first output terminal of the driver U2 is connected to the control electrode of the gallium nitride device 50 through the first driving resistor Ron. The second output terminal of the driver U2 is connected to the control electrode of the gallium nitride device 50 through the second driving resistor Roff. The driver U2 is configured to transmit a driving voltage of a first level to the gallium nitride device 50 through the first driving resistor Ron, or transmit a driving voltage of a second level to the gallium nitride device 50 through the second driving resistor Roff.

[0087] Specifically, the driver U2 can output a driving voltage of a first level to the gallium nitride device 50 through the first driving resistor Ron to turn on the gallium nitride device 50. The driver U2 can output a driving voltage of a second level to the gallium nitride device 50 through the second driving resistor Roff to turn off the gallium nitride device 50. Among them, the first level is a high level and the second level is a low level; or the first level is a low level and the second level is a high level.

[0088] Optionally, referring to Figure 3 , the comparison unit 310 includes a comparator U3;

[0089] The first input terminal of the comparator U3 is electrically connected to the current detection module 20. The second input terminal of the comparator U3 receives a reference voltage Vref. The output terminal of the comparator U3 is connected to the power supply adjustment unit 320.

[0090] Specifically, for example, the first input terminal of the comparator U3 is the inverting input terminal, the second input terminal of the comparator U3 is the non-inverting input terminal, and the trigger signal is a low-level signal. Therefore, when the actual voltage value corresponding to the actual current value connected to the first input terminal of the comparator U3 is less than the reference voltage, the comparator U3 outputs a high-level signal, that is, the inverted signal of the output trigger signal. When the actual voltage value corresponding to the actual current value connected to the first input terminal of the comparator U3 is greater than the reference voltage, the comparator U3 outputs a low-level trigger signal, causing the timer U1 to send a turn-off signal to the switching transistor Q1.

[0091] Exemplarily, the reference voltage Vref = kI sat , the voltage input to the first input terminal of the comparator U3 is V sense = kI ds , where k is the proportionality coefficient of the current detection module 20. When the current detection module 20 is a sampling resistor, k can be the resistance value of the sampling resistor. I ds is the actual current value between the first pole and the second pole of the gallium nitride device 50. V sense is the actual voltage value corresponding to the actual current value. I sat is the saturation current value of the gallium nitride device 50 under the normal driving voltage. The normal driving voltage can be determined according to the driving voltage range recommended in the specification of the gallium nitride device 50, or can be determined according to the driving voltage when the gallium nitride device 50 is operating normally. This embodiment does not make a limitation. Therefore, when the actual voltage value is greater than the reference voltage, it indicates that the actual current value of the gallium nitride device 50 is relatively large, and heat generation failure may occur. The technical solution of this embodiment sends a trigger signal to the timer U1 when the actual voltage value is greater than the reference voltage, causing the timer U1 to send a turn-off signal to the switching transistor Q1, increasing the output voltage of the power supply module 40, thereby increasing the driving voltage output by the driving module 10 and enhancing the saturation current capacity of the gallium nitride device 50, which can avoid heat generation failure of the gallium nitride device 50.

[0092] In some other embodiments, the first input terminal of the comparator U3 can be the non-inverting input terminal, the second input terminal of the comparator U3 is the inverting input terminal, and the trigger signal is a high-level signal. This embodiment does not make a limitation.

[0093] Optionally, the power supply module 40 includes an adjustable power supply chip. In this way, it is convenient to adjust the output voltage of the output terminal OUT of the power supply module 40, so as to meet the different power supply voltage requirements of the driving module 10, and further realize the adjustment of the performance of the gallium nitride device 50, improving the applicability of the gallium nitride device driving circuit.

[0094] Based on the above technical solution, Figure 4It is a schematic structural diagram of another gallium nitride device driving circuit provided by an embodiment of the present invention. Optionally, referring to Figure 4 , the gallium nitride device driving circuit further includes a controller 60;

[0095] The controller 60 is connected to the input end of the driving module 10. The controller 60 is configured to transmit a control signal P1 to the driving module 10, and the driving module 10 is configured to transmit a driving voltage to the control electrode of the gallium nitride device 50 according to the control signal P1.

[0096] Specifically, the controller 60 may include a Digital Signal Processor (DSP), or may include a Field Programmable Gate Array (FPGA), or may include other devices such as a single-chip microcomputer, which is not limited in this embodiment. The controller 60 can output the control signal P1 to the driver U2, so that the driver U2 outputs a driving voltage of low level or high level according to the control signal P1, thereby controlling the conduction or cutoff of the gallium nitride device 50.

[0097] Exemplarily, for example, the first input end of the comparator U3 is the inverting input end, the second input end of the comparator U3 is the non-inverting input end, and the trigger signal is a low-level signal. Figure 5 It is a driving timing diagram of a gallium nitride device provided by an embodiment of the present invention. As Figure 5 shown, from time t0 to time t1, the gallium nitride device 50 is conducting, and the actual current value I of the gallium nitride device 50 ds gradually increases, but does not exceed the saturation current value I of the gallium nitride device 50 under the normal driving voltage sat , and the actual voltage value V corresponding to the actual current value sense does not exceed the reference voltage Vref. The voltage V1 output by the comparator U3 is a high-level signal, that is, the inverted signal of the output trigger signal. The timer U1 is not triggered, the voltage V2 output by the timer U1 is a low-level signal, the switching transistor Q1 is conducting, the sixth resistor R6 is connected into the circuit, and the output voltage Vout of the power supply module 40 is a relatively small initial voltage.

[0098] From time t2 to time t4, the actual current value I of the gallium nitride device 50 ds gradually increases, and at time t3, the actual current value I of the gallium nitride device 50 ds reaches the saturation current value I of the gallium nitride device 50 under the normal driving voltage sat , and the actual voltage value V corresponding to the actual current value sexseReach the reference voltage Vref. The voltage V1 output by the comparator U3 is a low-level signal, which is the trigger signal. The timer U1 is triggered, and the voltage V2 output by the timer U1 is a high-level signal. The switching transistor Q1 is turned off, and the sixth resistor R6 is not connected to the circuit. The output voltage Vout of the power supply module 40 is a relatively large target voltage. And the duration of the high-level output of the timer U1 is the preset duration T. Until the moment t5, the duration of the relatively large voltage output by the power supply module 40 is relatively long, which is longer than the single conduction duration of the gallium nitride device 50. It can ensure that the duration of the enhanced saturation ability of the gallium nitride device 50 is longer than the duration of the current increase of the gallium nitride device 50, so as to ensure that the duration of the enhanced saturation ability of the gallium nitride device 50 is longer than the duration when the actual voltage value corresponding to the actual current value of the gallium nitride device 50 is greater than the reference voltage, and further ensure that the actual current value of the gallium nitride device 50 does not reach the saturation current limit value, so that it will not heat up and fail.

[0099] After the moment t5, the timer U1 stops outputting the turn-off signal, the switching transistor Q1 conducts, and the output voltage of the power supply module 40 returns to the initial voltage.

[0100] Therefore, the gallium nitride device of this embodiment can increase the power supply voltage of the drive module 10 in time when the current of the gallium nitride device 50 is relatively large, thereby increasing the drive voltage output by the drive module 10, and further increasing the voltage of the control electrode of the gallium nitride device 50, enhancing the saturation current ability of the gallium nitride device 50, making it not easy for the gallium nitride device 50 to reach the current limit value, and further not easy to heat up and fail.

[0101] The above specific implementation manners do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A gallium nitride device driving circuit, characterized in that: include: Driving module, current detection module, power regulation module and power supply module; The driving module is connected to the control electrode of the gallium nitride device, and the driving module is configured to output a driving voltage to the gallium nitride device; the power supply end of the driving module is connected to the output end of the power supply module; The current detection module is connected to the first electrode of the gallium nitride device, and the current detection module is configured to detect an actual current value of the gallium nitride device; The power regulation module is connected to the current detection module, and the power regulation module is respectively connected to the output end and the regulation end of the power module. The power regulation module is configured to adjust the output voltage of the power module when the actual voltage value corresponding to the actual current value is greater than the reference voltage.

2. The gallium nitride device driving circuit according to claim 1, characterized in that: The power supply regulating module comprises a comparing unit and a power supply regulating unit; The first input end of the comparison unit is connected to the current detection module, the second input end of the comparison unit is connected to the reference voltage, the output end of the comparison unit is connected to the power supply adjustment unit, and the comparison unit is configured to send a trigger signal to the power supply adjustment unit when the actual voltage value corresponding to the actual current value is greater than the reference voltage; The power regulating unit is connected to the output terminal and the regulating terminal of the power module respectively, and the power regulating unit is configured to regulate the output voltage of the power module in response to the trigger signal.

3. The gallium nitride device driving circuit according to claim 2, characterized in that: The power supply regulating unit comprises a timing subunit and a power supply regulating subunit; The trigger end of the timing subunit is connected to the output end of the comparison unit, and the output end of the timing subunit is connected to the control end of the power regulation subunit; The timing subunit is configured to send a shutdown signal of a preset duration to the power regulation subunit in response to the trigger signal, and send a conduction signal to the power regulation subunit when the trigger signal is not received; The power regulating subunit is connected to the output end and the regulating end of the power module respectively, and the power regulating subunit is configured to adjust the output voltage of the power module to an initial voltage according to the on-signal, or to adjust the output voltage of the power module to a target voltage according to the off-signal; wherein the target voltage is greater than the initial voltage.

4. The gallium nitride device driving circuit according to claim 3, characterized in that: The timing subunit includes a timer, a first resistor, a second resistor and a first capacitor; The trigger end of the timer is electrically connected to the output end of the comparison unit; the output end of the timer is connected to the control end of the power regulation subunit; The power supply end of the timer is connected to a first power supply; The power supply end of the timer is electrically connected to the first end of the first resistor, and the second end of the first resistor is grounded through the first capacitor; The timing end of the timer is electrically connected to the second end of the first resistor; The second resistor is connected between a power supply terminal of the timer and an output terminal of the timer.

5. The gallium nitride device driving circuit according to claim 3, characterized in that: The power regulation subunit includes a switch transistor, a third resistor, a fourth resistor, a fifth resistor and a sixth resistor; The control electrode of the switch transistor is electrically connected to the output end of the timing sub-unit, and the first electrode of the switch transistor is grounded; The third resistor is connected between the control electrode of the switch transistor and the first electrode of the switch transistor; The first end of the fourth resistor is electrically connected to the output end of the power module, the second end of the fourth resistor is electrically connected to the first end of the fifth resistor, and the second end of the fifth resistor is grounded; The sixth resistor is connected between the second electrode of the switch transistor and the regulating end of the power module.

6. The gallium nitride device driving circuit according to claim 3, characterized in that: The preset time length is greater than a single turn-on time length of the gallium nitride device.

7. The gallium nitride device driving circuit according to claim 1, characterized in that: The driving module includes a driver, a first driving resistor and a second driving resistor; The first power supply terminal of the driver is connected to the output terminal of the power supply module, the second power supply terminal of the driver is grounded, the input terminal of the driver is connected to the control signal, the first output terminal of the driver is connected to the control electrode of the gallium nitride device through the first driving resistor, and the second output terminal of the driver is connected to the control electrode of the gallium nitride device through the second driving resistor; the driver is configured to transmit a driving voltage of a first level to the gallium nitride device through the first driving resistor, or transmit a driving voltage of a second level to the gallium nitride device through the second driving resistor.

8. The gallium nitride device driving circuit according to claim 2, characterized in that: The comparison unit includes a comparator; The first input end of the comparator is electrically connected to the current detection module, the second input end of the comparator is connected to the reference voltage, and the output end of the comparator is connected to the power supply adjustment unit.

9. The gallium nitride device driving circuit according to claim 1, characterized in that: The power module includes an adjustable power chip.

10. The gallium nitride device driving circuit according to claim 1, characterized in that: The gallium nitride device driving circuit also includes a controller; The controller is connected to the input end of the driving module. The controller is configured to transmit a control signal to the driving module. The driving module is configured to transmit a driving voltage to the control electrode of the gallium nitride device according to the control signal.

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