A gallium nitride half-bridge drive circuit

Abstract

The application belongs to the technical field of gallium nitride driving and relates to a gallium nitride half-bridge driving circuit. The gallium nitride driving circuit comprises a high-frequency driving signal generation module for generating complementary first and second high-frequency signals without dead zones; an isolation type dead zone generation module, an input end of which is connected with an output end of the high-frequency driving signal generation module, for adjusting dead zone time of the first and second high-frequency signals to a preset value and outputting first and second target high-frequency signals; a voltage matching module, an input end of which is connected with an output end of the isolation type dead zone generation module, for adjusting voltages of the first and second target high-frequency signals; and an isolation driving module, an input end of which is connected with an output end of the voltage matching module, for adjusting rising and falling edges of the first and second target high-frequency signals and outputting first and second driving signals to drive upper and lower tubes in the gallium nitride half-bridge circuit.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gallium nitride driving, in particular to a gallium nitride half-bridge driving circuit. BACKGROUND

[0002] In recent years, the volume, weight and efficiency of power electronic devices have been increasingly stringent requirements in the application fields of data center power supply, wireless power transmission, radio frequency power amplification, and so on, which leads to the requirement of the switching frequency of power electronic power devices in these power supply devices being continuously improved. For silicon-based semiconductor power devices, there is limited space for further improving the upper limit of the switching frequency. At the same time, with the increasingly perfect manufacturing process of gallium nitride power devices, a large number of gallium nitride power devices are gradually applied to the field of ultra-high frequency power electronics. Because the on-state and switching loss of gallium nitride devices are low, and the gallium nitride devices have better reverse recovery characteristics than Si-MOSFETs, the overall efficiency of the power supply can be significantly improved. Moreover, the gallium nitride material itself has the advantages of high band gap, high electron mobility, high critical breakdown field and high electron saturation velocity, and therefore the switching class power amplifier based on gallium nitride power devices can provide high frequency, high power and low loss sinusoidal alternating current for radio frequency loads. In order to fully exert the advantages of gallium nitride power devices, a stable and high-frequency driving circuit needs to be designed.

[0003] The gallium nitride half-bridge circuit is a circuit architecture widely used in high-performance power conversion, and its core feature is to use gallium nitride power devices (for example: GaN-HEMT) as switching elements to achieve high-efficiency and high-speed power conversion. Figure 1 As shown in the gallium nitride half-bridge circuit and the gallium nitride half-bridge bootstrap driving circuit in the prior art, the gallium nitride half-bridge circuit includes two gallium nitride power devices (such as Figure 1 , and ), the upper tube is connected to the positive pole of the power supply as a high-end switch, and the lower tube is connected to the load or ground as a low-end switch, by controlling the upper tube and the lower tube to be turned on alternately according to the time sequence, the current flowing direction to the load is controlled; the gallium nitride half-bridge bootstrap driving circuit includes a bootstrap capacitor , a bootstrap diode and a bootstrap type driving chip , when the bootstrap type driving chip controls the lower tube in the gallium nitride half-bridge circuit to be turned on based on the PWM signal, a closed path is formed between the positive pole of the power supply and the ground, and the load current flows through the lower tube , so that the upper tube The source is close to ground potential, and the power supply voltage passes through the bootstrap diode. Charge is stored in the bootstrap capacitor. When bootstrap driver chip Based on PWM signal control of the lower transistor Shut down, connect pipe When turned on, the bootstrap capacitor Discharge is the upper tube The gate is provided with a floating voltage, ensuring that the difference between the gate potential and the source potential is greater than the threshold voltage, thereby ensuring that the upper transistor... Effective conduction; due to the upper pipe and lower pipe Simultaneous conduction can cause a short circuit in the circuit, therefore it is often done in the upper tube. and lower pipe During the switching process, a certain time interval (i.e., dead time) is allowed, and the dead time control is managed accordingly. and lower pipe Simultaneously shut off to prevent the upper pipe from being connected. and lower pipe Both transistors are turned on during the switching process. However, during the dead time after the upper transistor is turned off, the current continues to flow in the original direction due to the inductance in the load, causing the lower transistor to... As a freewheeling path operating in the third quadrant, meaning the directions of voltage and current are opposite to those during normal conduction, the lower transistor... Drain-source voltage A negative voltage will further cause the bootstrap capacitor to... Overcharged, thus affecting the upper tube Applying excessively high voltage to the gate causes the upper transistor to... Overvoltage can cause breakdown, thus damaging gallium nitride power devices. To reduce bootstrap capacitance... When overcharged, the bootstrap driver circuit can only drive the gallium nitride half-bridge circuit at a lower operating frequency. However, reducing the operating frequency of the bootstrap driver circuit also reduces the switching speed in the gallium nitride half-bridge circuit, which cannot fully utilize the advantage of the fast switching speed of gallium nitride power devices and reduces the response speed and power density of the gallium nitride half-bridge circuit.

[0004] In summary, when the gallium nitride half-bridge bootstrap drive circuit in the prior art drives the gallium nitride half-bridge circuit, there is a problem that the bootstrap capacitor is overcharged, which leads to the upper transistor being overvoltaged and broken down. If the operating frequency of the bootstrap drive circuit is reduced to reduce the chance of overcharging of the bootstrap capacitor, the advantage of the fast switching speed of gallium nitride power devices cannot be fully utilized, thus reducing the response speed and power density of the gallium nitride half-bridge circuit. Summary of the Invention

[0005] To this end, the technical problem to be solved by the present application is to overcome the problem that the bootstrap capacitor in the prior art GaN half-bridge bootstrap drive circuit is overcharged, thereby causing the upper tube to be overvoltage breakdown.

[0006] To solve the above technical problems, the present application provides a GaN half-bridge drive circuit, comprising:

[0007] a high-frequency drive signal generation module for generating complementary first and second high-frequency signals without dead zones; the duty cycles of the first and second high-frequency signals are both 50%;

[0008] an isolation type dead zone generation module, a first input end of which is connected to a first output end of the high-frequency drive signal generation module, and a second input end of which is connected to a second output end of the high-frequency drive signal generation module; for adjusting the dead zone time of the first and second high-frequency signals to a preset value, and outputting first and second target high-frequency signals;

[0009] a voltage matching module, comprising a first voltage matching circuit and a second voltage matching circuit; an input end of the first voltage matching circuit is connected to a first output end of the isolation type dead zone generation module, for adjusting the voltage of the first target high-frequency signal; an input end of the second voltage matching circuit is connected to a second output end of the isolation type dead zone generation module, for adjusting the voltage of the second target high-frequency signal;

[0010] an isolation drive module, comprising a first isolation drive circuit and a second isolation drive circuit; an input end of the first isolation drive circuit is connected to an output end of the first voltage matching circuit, for adjusting the rising edge and falling edge of the first target high-frequency signal, and outputting a first drive signal to drive the upper tube in the GaN half-bridge circuit; an input end of the second isolation drive circuit is connected to an output end of the second voltage matching circuit, for adjusting the rising edge and falling edge of the second target high-frequency signal, and outputting a second drive signal to drive the lower tube in the GaN half-bridge circuit.

[0011] Preferably, it further comprises an isolation power supply module, which comprises:

[0012] a first isolation power supply chip, an output end of which is connected to a first output power supply end of the isolation type dead zone generation module, for supplying power to the output end of the isolation type dead zone generation module;

[0013] a second isolation power supply chip, an output end of which is connected to a second output power supply end of the isolation type dead zone generation module, for supplying power to the output end of the isolation type dead zone generation module;

[0014] A third isolated power supply chip, an output end of which is connected with a power input end of the first isolated drive circuit, for supplying power to the first isolated drive circuit;

[0015] A fourth isolated power supply chip, an output end of which is connected with a power input end of the second isolated drive circuit, for supplying power to the second isolated drive circuit.

[0016] Preferably, further comprising a protection module, the protection module comprising:

[0017] A first protection circuit, an input end of which is connected with an output end of the first isolated drive circuit, and an output end of which is connected with a gate of an upper tube in the gallium nitride half-bridge circuit, for suppressing oscillation of the first drive signal;

[0018] A second protection circuit, an input end of which is connected with an output end of the second isolated drive circuit, and an output end of which is connected with a gate of a lower tube in the gallium nitride half-bridge circuit, for suppressing oscillation of the second drive signal.

[0019] Preferably, the isolated dead-time generation module comprises:

[0020] An isolated drive chip, a first signal input pin of which serves as a first input end of the isolated dead-time generation module, and is connected with a first output end of the high-frequency drive signal generation module; a second signal input pin of which serves as a second input end of the isolated dead-time generation module, and is connected with a second output end of the high-frequency drive signal generation module; a first signal output pin of which serves as a first output end of the isolated dead-time generation module; and a second signal output pin of which serves as a second output end of the isolated dead-time generation module;

[0021] A first resistor, a first end of which is connected with a dead-time input pin of the isolated drive chip, and a second end of which is grounded, for adjusting the dead-time of the first high-frequency signal and the second high-frequency signal by changing a resistance value of the first resistor; wherein a calculation formula of the dead-time is:

[0022] ,

[0023] Wherein, represents the dead-time of the first target high-frequency signal and the second target high-frequency signal; represents the resistance value of the first resistor.

[0024] Preferably, the first voltage matching circuit and the second voltage matching circuit each comprise:

[0025] A second resistor, a first end of which serves as an input end of the voltage matching circuit;

[0026] A third resistor, a first end of which is connected to a second end of the second resistor as an output end of the voltage matching circuit, and a second end of which is grounded.

[0027] Preferably, the first isolation driving circuit and the second isolation driving circuit each comprise:

[0028] A high-speed driving chip, a signal input pin of which is an input end of the isolation driving circuit; a power input pin of which is a power input end of the isolation driving circuit; and an enable pin of which is grounded.

[0029] A fourth resistor, a first end of which is connected to an output high-end signal pin of the high-speed driving chip.

[0030] A fifth resistor, a first end of which is connected to an output low-end signal pin of the high-speed driving chip, and a second end of which is connected to a second end of the fourth resistor as an output end of the isolation driving circuit.

[0031] Preferably, the first protection circuit and the second protection circuit each comprise:

[0032] A diode, a positive electrode of which is grounded, and a negative electrode of which is an input end of the protection circuit.

[0033] A transient suppression voltage regulator diode, a positive electrode of which is connected to a negative electrode of the diode, and a negative electrode of which is grounded.

[0034] A sixth resistor, a first end of which is connected to a positive electrode of the transient suppression voltage regulator diode as an output end of the protection circuit, and a second end of which is grounded.

[0035] Preferably, the first isolation power supply chip, the second isolation power supply chip, the third isolation power supply chip, and the fourth isolation power supply chip comprise B0509-2WR3 and B0505-2WR3.

[0036] Preferably, the isolation driving chip comprises Nsi6602A and Ucc21520.

[0037] Preferably, the high-speed driving chip comprises HD1001 and LMG1020.

[0038] The gallium nitride half-bridge driving circuit provided by the application generates two driving signals by adopting a two-stage driving mode to isolate and drive the upper tube and the lower tube in the gallium nitride half-bridge circuit, first generates two high-frequency signals with no dead zone and a duty cycle of 50%; the dead zone time of the two high-frequency signals is adjusted by using an isolation type dead zone generation module to realize one-stage driving, so as to prevent the overlap of the two starting signals at the high level, so that the upper tube and the lower tube in the gallium nitride bridge circuit are simultaneously turned on, resulting in short circuit; in order to match the voltage of the two high-frequency signals with the input voltage of the isolation driving module, two isolated voltage matching circuits are designed to adjust the voltage of the two high-frequency signals respectively, the working voltage range of the isolation type dead zone generation module and the isolation driving module is improved, and then the working frequency of the driving circuit is improved; finally, two independent isolation driving circuits are used for two-stage driving, since each isolation driving circuit is a single-input single-output circuit, the edges of the two high-frequency signals can be adjusted respectively, two complementary driving signals with dead zone time are generated to independently drive the upper tube and the lower tube in the gallium nitride bridge circuit; the application does not use bootstrap capacitors and bootstrap diodes to bootstrap drive the upper tube and the lower tube in the gallium nitride half-bridge circuit, but directly generates two complementary driving signals with dead zone to isolate and drive the upper tube and the lower tube, by providing more stable and independent gate voltages for the upper tube and the lower tube, the problem of device damage caused by overcharging of the bootstrap capacitor is avoided, and the working frequency of the driving circuit and the switching speed of the gallium nitride half-bridge circuit are not required to be reduced, so that high-frequency driving of the gallium nitride half-bridge circuit can be realized, and the advantage of fast switching speed of the gallium nitride power device is fully utilized. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to make the content of the application more easily understood, the application will be further described in detail below according to specific embodiments of the application and in conjunction with the drawings, in which

[0040] Figure 1 The gallium nitride half-bridge circuit provided by the application and the gallium nitride half-bridge bootstrap driving circuit in the prior art are shown in the schematic diagram;

[0041] Figure 2 The overall structure of the gallium nitride half-bridge driving circuit provided by the application is shown in the schematic diagram;

[0042] Figure 3 The first high-frequency signal and the second high-frequency signal provided by the application are shown in the schematic diagram;

[0043] Figure 4 The input signal and the output signal of the isolation type dead zone generation module provided by the application are shown in the schematic diagram; wherein, Figure 4 (a) in the above (a) is the input signal schematic diagram of the isolation type dead zone generation module, Figure 4 (b) in the above (b) is the output signal schematic diagram of the isolation type dead zone generation module;

[0044] Figure 5 A schematic diagram of the circuit principle of an isolation dead-time generation module provided in this application;

[0045] Figure 6 A schematic diagram of a voltage matching circuit provided in this application;

[0046] Figure 7 A schematic diagram of an isolation drive circuit provided in this application;

[0047] Figure 8 A schematic diagram of the circuit principle of an isolated power supply chip provided in this application;

[0048] Figure 9 A schematic diagram of a protection circuit is provided for this application;

[0049] Figure 10 This is a schematic diagram of the gallium nitride half-bridge drive circuit provided in an embodiment of this application;

[0050] Figure 11 This is a waveform diagram of the driving signal used to drive a gallium nitride half-bridge circuit using the driving circuit provided in the embodiments of this application; wherein, Figure 11 (a) in the diagram is the waveform of the first type of driving signal. Figure 11 (b) in the diagram is the waveform of the second type of driving signal. Detailed Implementation

[0051] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0052] Please see Figure 2 , Figure 2 This is a schematic diagram of the overall structure of the gallium nitride half-bridge drive circuit provided in this application. The gallium nitride half-bridge drive circuit includes: a high-frequency drive signal generation module, an isolation dead-time generation module, a voltage matching module, and an isolation drive module.

[0053] The high-frequency drive signal generation module is used to generate complementary, dead-zone-free first and second high-frequency signals. Both the first and second high-frequency signals have a duty cycle of 50%.

[0054] For example, such as Figure 3 The diagram shows a complementary dead-zone-free first high-frequency signal and a second high-frequency signal provided in an embodiment of this application. In the diagram, A and B represent the first high-frequency signal and the second high-frequency signal, respectively.

[0055] The first input end of the isolation type dead zone generation module is connected with the first output end of the high-frequency drive signal generation module, and the second input end is connected with the second output end of the high-frequency drive signal generation module; and the dead zone time of the first high-frequency signal and the second high-frequency signal is adjusted to a preset value, and the first target high-frequency signal and the second target high-frequency signal are output.

[0056] Specifically, the complementary first high-frequency signal and the second high-frequency signal without dead zone will generate the complementary first target high-frequency signal and the second target high-frequency signal with dead zone time and duty cycle slightly less than 50% after passing through the isolation type dead zone generation module. By controlling the dead zone time of the two signals, the high level overlap of the two drive signals can be prevented, so that the upper tube and the lower tube in the gallium nitride half-bridge circuit are turned on at the same time, which leads to short circuit, causes device damage and other consequences.

[0057] For example, as shown in Figure 4 The input signal and the output signal of the isolation type dead zone generation module provided by the embodiment of the application are shown in the schematic diagram. Figure 4 The input signal of the isolation type dead zone generation module is shown in (a) in the schematic diagram, in which A and B represent the first high-frequency signal and the second high-frequency signal output by the high-frequency drive signal generation module, respectively; Figure 4 The output signal of the isolation type dead zone generation module is shown in (b) in the schematic diagram, in which A and B represent the first target high-frequency signal and the second target high-frequency signal output by the isolation type dead zone generation module, respectively, and DT is the dead zone time of the two high-frequency signals.

[0058] The voltage matching module includes a first voltage matching circuit and a second voltage matching circuit.

[0059] The input end of the first voltage matching circuit is connected with the first output end of the isolation type dead zone generation module, and is used for adjusting the voltage of the first target high-frequency signal. The input end of the second voltage matching circuit is connected with the second output end of the isolation type dead zone generation module, and is used for adjusting the voltage of the second target high-frequency signal.

[0060] The output voltage of the isolation type dead zone generation module is adjusted by using the voltage matching module, so as to match the input voltage of the isolation drive module, so that the isolation type dead zone generation module and the isolation drive module can work in a wider voltage range.

[0061] The isolation drive module includes a first isolation drive circuit and a second isolation drive circuit.

[0062] The input end of the first isolation driving circuit is connected with the output end of the first voltage matching circuit, used for adjusting the rising edge and falling edge of the first target high-frequency signal, outputting the first driving signal to drive the upper tube in the gallium nitride half-bridge circuit. The input end of the second isolation driving circuit is connected with the output end of the second voltage matching circuit, used for adjusting the rising edge and falling edge of the second target high-frequency signal, outputting the second driving signal to drive the lower tube in the gallium nitride half-bridge circuit.

[0063] The application does not use a bootstrap capacitor and a bootstrap diode to bootstrap drive the upper tube and the lower tube in the gallium nitride half-bridge circuit, but directly generates two complementary driving signals with a dead zone to isolate drive the upper tube and the lower tube, provides more stable and independent gate voltages for the upper tube and the lower tube, avoids the problem of overcharging of the bootstrap capacitor, and further causes damage to the device, without the need to reduce the working frequency of the driving circuit and the rate of switching action in the gallium nitride half-bridge circuit, so that high-frequency driving of the gallium nitride half-bridge circuit can be realized, and the advantage of fast switching speed of the gallium nitride power device is fully utilized.

[0064] Specifically, the isolation type dead zone generation module comprises:

[0065] The isolation driving chip has a first signal input pin as a first input end of the isolation type dead zone generation module, connected with a first output end of the high-frequency driving signal generation module; a second signal input pin as a second input end of the isolation type dead zone generation module, connected with a second output end of the high-frequency driving signal generation module; a first signal output pin as a first output end of the isolation type dead zone generation module; and a second signal output pin as a second output end of the isolation type dead zone generation module.

[0066] The first resistor has a first end connected with the dead zone time input pin of the isolation driving chip and a second end grounded, and the dead zone time of the first high-frequency signal and the second high-frequency signal is adjusted by changing the resistance value of the first resistor.

[0067] Further, the isolation driving chip can be selected from chips such as Nsi6602A and Ucc21520 with hardware configuration dead zone time.

[0068] For example, as shown in Figure 5The diagram shows a schematic of the circuit principle of an isolated dead-time generation module using an Nsi6602A chip as the isolation driver chip, as provided in this embodiment. In the diagram, VIA and VIB are the first and second input terminals of the isolated dead-time generation module; VDDI is the input power supply terminal of the isolated dead-time generation module; GNDI is the input ground pin; NC is the empty signal pin; VDDA and VDDB are the first and second output power supply terminals of the isolated dead-time generation module; GNDA and GNDB are the output ground pins; DT is the dead-time input pin of the isolation driver chip, connected to a first resistor R1. The dead-time can be controlled by changing the value of the first resistor R1. Specifically, the formula for calculating the dead-time is:

[0069] ,

[0070] in, This represents the dead time of the high-frequency signals from the first and second targets. This indicates the resistance value of the first resistor.

[0071] Furthermore, both the first voltage matching circuit and the second voltage matching circuit include:

[0072] The second resistor has its first end serving as the input terminal of the voltage matching circuit.

[0073] The third resistor has its first end connected to the second end of the second resistor as the output terminal of the voltage matching circuit, and its second end is grounded.

[0074] like Figure 6 The diagram shown is a schematic of the voltage matching circuit provided in this embodiment. The circuit consists of a second resistor connected in series. and the third resistor composition, The output signal for the isolation dead-time generation module, This is the output signal of the voltage matching circuit; Voltage matching between the isolation dead-time generation module and the isolation drive module can be achieved by adjusting the values ​​of the second and third resistors.

[0075] Furthermore, both the first isolation drive circuit and the second isolation drive circuit include:

[0076] The high-speed driver chip uses its signal input pin as the input terminal of the isolated driver circuit; its power input pin as the power input terminal of the isolated driver circuit; and its enable pin is grounded.

[0077] The fourth resistor has its first end connected to the high-side output signal pin of the high-speed driver chip;

[0078] The fifth resistor has a first end connected with the output low end signal pin of the high-speed driving chip and a second end connected with the second end of the fourth resistor as an output end of the isolation driving circuit.

[0079] Further, the high-speed driving chip can be selected from HD1001 chip of Jianhong Microelectronics, LMG1020 of T1, and the like, and the response speed thereof can reach ns level.

[0080] For example, as shown in Figure 7 Fig. 1 shows a schematic diagram of the isolation driving circuit when the high-speed driving chip is HD1001 according to the embodiment. The left side of the figure is a schematic diagram of the circuit of the HD1001 chip, the VDD pin of the HD1001 chip is used as a power input end of the isolation driving circuit; IN+ is a signal input pin; IN- is an enable pin; U1 is a same-direction Schmitt trigger; U2 is a reverse Schmitt trigger; U3 is an AND gate; Q1 is an N-channel field effect transistor; Q2 is a P-channel field effect transistor; OUTH is an output high end signal pin; OUTL is an output low end signal pin; IN- inputs a low level signal, IN+ inputs a high level signal, a high frequency signal is output through the AND gate, Q1 and Q2 are driven to be turned on or turned off, so that OUTH and OUTL output a large current and a super high-speed driving signal, and the driving signal is output through the fourth resistor and the fifth resistor to optimize the edge of the driving signal, so as to output the driving signal to drive the gallium nitride half-bridge circuit.

[0081] Optionally, as shown in Figure 2 in some embodiments of the present application, the gallium nitride half-bridge driving circuit further comprises an isolation power supply module, and the isolation power supply module specifically comprises:

[0082] a first isolation power supply chip, an output end of which is connected with a first output power supply end of the isolation type dead zone generation module, and used for supplying power to the output end of the isolation type dead zone generation module;

[0083] a second isolation power supply chip, an output end of which is connected with a second output power supply end of the isolation type dead zone generation module, and used for supplying power to the output end of the isolation type dead zone generation module;

[0084] a third isolation power supply chip, an output end of which is connected with a power input end of the first isolation driving circuit, and used for supplying power to the first isolation driving circuit;

[0085] a fourth isolation power supply chip, an output end of which is connected with a power input end of the second isolation driving circuit, and used for supplying power to the second isolation driving circuit.

[0086] Further, the first, second, third and fourth isolated power supply chips can use modules such as Jinsengyang B0509-2WR3 and Yikuan B0505-2WR3.

[0087] As shown in FIG. 1, the GaN half-bridge driving circuit includes an isolated power supply, an isolated dead-zone generating module, a first isolated driving circuit, a second isolated driving circuit, a GaN half-bridge circuit, and a protection module. Figure 8 As shown in FIG. 2, the isolated power supply includes a first isolated power supply chip, a second isolated power supply chip, a third isolated power supply chip and a fourth isolated power supply chip.

[0088] Further, as shown in FIG. 3, in some embodiments of the present application, the GaN half-bridge driving circuit further includes a protection module, which specifically includes: Figure 2

[0089] A first protection circuit, an input end of which is connected to an output end of the first isolated driving circuit, and an output end of which is connected to a gate of the upper transistor in the GaN half-bridge circuit, for suppressing oscillation of the first driving signal;

[0090] A second protection circuit, an input end of which is connected to an output end of the second isolated driving circuit, and an output end of which is connected to a gate of the lower transistor in the GaN half-bridge circuit, for suppressing oscillation of the second driving signal.

[0091] Since the first driving signal and the second driving signal need to be transmitted to the upper transistor and the lower transistor in the GaN half-bridge circuit through wires, the parasitic parameters in the wires can cause oscillation of the driving signal waveform, thereby causing damage to the GaN devices in the GaN half-bridge circuit. Therefore, the present application suppresses the oscillation of the first driving signal and the second driving signal through the first protection circuit and the second protection circuit, respectively, thereby preventing damage to the driving circuit or the devices in the GaN half-bridge circuit caused by the oscillation of the driving signal waveform due to the parasitic parameters.

[0092] Further, the first protection circuit and the second protection circuit each include:

[0093] A diode, a positive electrode of which is grounded, and a negative electrode of which is used as an input end of the protection circuit;

[0094] A transient voltage suppression diode, a positive electrode of which is connected to the negative electrode of the diode, and a negative electrode of which is grounded;

[0095] A sixth resistor, a first end of which is connected to the positive electrode of the transient voltage suppression diode as an output end of the protection circuit, and a second end of which is grounded.

[0096] As shown in FIG. 4, the GaN half-bridge driving circuit includes an isolated power supply, an isolated dead-zone generating module, a first isolated driving circuit, a second isolated driving circuit, a GaN half-bridge circuit, and a protection module. Figure 9 ​The principle diagram of the protection circuit provided by the embodiment is shown, and the negative electrode of the diode D1 is connected to the signal input end of the protection circuit; the positive electrode of the transient voltage suppression diode D2 is connected to the negative electrode of the diode D1; the first end of the sixth resistor is connected to the positive electrode of the transient voltage suppression diode D2 as the output end of the protection circuit, and the output end is connected to the gallium nitride field effect transistor Q in the gallium nitride half-bridge circuit; the positive electrode of the diode D1, the negative electrode of the transient voltage suppression diode D2 and the second end of the sixth resistor are grounded.

[0097] Due to the existence of the parasitic inductance of the wire, high-frequency signals will inevitably generate oscillation in the transmission process, and excessive oscillation will cause damage to the devices in the driving circuit or the gallium nitride half-bridge circuit. The negative voltage clamping of the reverse-parallel diode D1 is designed to clamp the voltage drop of the diode near the voltage drop of the diode, the transient voltage suppression diode D2 is used to absorb the voltage peak, and the sixth resistor can not only perform impedance matching, but also can be used as a pull-down resistor to prevent the gallium nitride field effect transistor Q in the gallium nitride half-bridge circuit from being misdirected.

[0098] As Figure 10 shown is the principle diagram of the gallium nitride half-bridge driving circuit provided by the embodiment, in which 10 is an isolation type dead zone generation module; 20 is a voltage matching module, 201 is a first matching circuit, and 202 is a second matching circuit; 30 is an isolation driving module, 301 is a first isolation driving circuit, and 302 is a second isolation driving module; 40 is an isolation power supply module, 401 is a first isolation power supply chip, 402 is a second isolation power supply chip, 403 is a third isolation power supply chip, and 404 is a fourth isolation power supply chip; 50 is a protection module, 501 is a first protection circuit, and 502 is a second protection circuit; QA and QB are respectively the upper tube and the lower tube in the gallium nitride half-bridge circuit.

[0099] Figure 11 As shown in the driving circuit shown in Figure 10 , the driving signal waveform diagram obtained by driving the gallium nitride half-bridge circuit is shown; wherein, Figure 11 (a) in (a) is a first driving signal waveform diagram, which can realize 4MHz level super high speed driving; Figure 11 (b) in (b) is a second driving signal waveform diagram, which can realize 8MHz level super high speed driving. From Figure 11 it can be seen that the gallium nitride half-bridge driving circuit provided by the application can realize MHz level super high speed driving in actual work.

[0100] Obviously, the above embodiments are merely example for clearly illustrating, and are not limitation to the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments are not required to be enumerated, and the obvious changes or variations derived from the above are still within the protection scope of the present application.

Claims

1. A gallium nitride half-bridge drive circuit, characterized by, The application relates to a high-frequency drive signal generation module, a voltage matching module, an isolation drive module and a protection module. The high-frequency drive signal generation module is used for generating complementary first and second high-frequency signals without dead zones. The duty cycles of the first and second high-frequency signals are both 50%. The isolation type dead zone generation module has a first input end connected with a first output end of the high-frequency drive signal generation module and a second input end connected with a second output end of the high-frequency drive signal generation module, and is used for adjusting the dead zone time of the first and second high-frequency signals to a preset value and outputting first and second target high-frequency signals. The voltage matching module comprises a first voltage matching circuit and a second voltage matching circuit. The first voltage matching circuit has an input end connected with a first output end of the isolation type dead zone generation module and is used for adjusting the voltage of the first target high-frequency signal. The second voltage matching circuit has an input end connected with a second output end of the isolation type dead zone generation module and is used for adjusting the voltage of the second target high-frequency signal.

2. The gallium nitride half-bridge driver circuit of claim 1, wherein, The isolation drive module comprises a first isolation drive circuit and a second isolation drive circuit. The first isolation drive circuit has an input end connected with an output end of the first voltage matching circuit and is used for adjusting the rising and falling edges of the first target high-frequency signal and outputting a first drive signal to drive an upper tube in a gallium nitride half-bridge circuit. The second isolation drive circuit has an input end connected with an output end of the second voltage matching circuit and is used for adjusting the rising and falling edges of the second target high-frequency signal and outputting a second drive signal to drive a lower tube in the gallium nitride half-bridge circuit. The isolation power supply module comprises: A first isolation power supply chip has an output end connected with a first output power supply end of the isolation type dead zone generation module and is used for supplying power to the output end of the isolation type dead zone generation module.

3. The gallium nitride half-bridge driver circuit of claim 1, wherein, A second isolation power supply chip has an output end connected with a second output power supply end of the isolation type dead zone generation module and is used for supplying power to the output end of the isolation type dead zone generation module. A third isolation power supply chip has an output end connected with a power input end of the first isolation drive circuit and is used for supplying power to the first isolation drive circuit. A fourth isolation power supply chip has an output end connected with a power input end of the second isolation drive circuit and is used for supplying power to the second isolation drive circuit.

4. The gallium nitride half-bridge driver circuit of claim 1, wherein, The protection module comprises: A first protection circuit has an input end connected with an output end of the first isolation drive circuit and an output end connected with a gate of the upper tube in the gallium nitride half-bridge circuit and is used for inhibiting the oscillation of the first drive signal. A second protection circuit has an input end connected with an output end of the second isolation drive circuit and an output end connected with a gate of the lower tube in the gallium nitride half-bridge circuit and is used for inhibiting the oscillation of the second drive signal. The isolation type dead zone generation module comprises: The first signal input pin of the isolation driving chip is connected with the first output end of the high-frequency driving signal generating module as the first input end of the isolation type dead zone generating module; the second signal input pin of the isolation driving chip is connected with the second output end of the high-frequency driving signal generating module as the second input end of the isolation type dead zone generating module; the first signal output pin of the isolation driving chip is the first output end of the isolation type dead zone generating module; and the second signal output pin of the isolation driving chip is the second output end of the isolation type dead zone generating module. The first end of the first resistor is connected with the dead zone time input pin of the isolation driving chip, and the second end of the first resistor is grounded, so that the dead zone time of the first high-frequency signal and the second high-frequency signal is adjusted by changing the resistance value of the first resistor; wherein, the calculation formula of the dead zone time is as follows: ， wherein, represents a dead time of the first target high-frequency signal and the second target high-frequency signal; represents a resistance value of the first resistor.

5. The gallium nitride half-bridge driver circuit of claim 1, wherein, The first voltage matching circuit and the second voltage matching circuit both include: The first end of the second resistor is connected with the second end of the second resistor as the input end of the voltage matching circuit. The first end of the third resistor is connected with the second end of the second resistor as the output end of the voltage matching circuit, and the second end of the third resistor is grounded.

6. The gallium nitride half-bridge driver circuit of claim 1, wherein, The first isolation driving circuit and the second isolation driving circuit both include: The signal input pin of the high-speed driving chip is connected with the input end of the isolation driving circuit; the power supply input pin of the high-speed driving chip is connected with the power supply input end of the isolation driving circuit; and the enable pin of the high-speed driving chip is grounded. The first end of the fourth resistor is connected with the output high-end signal pin of the high-speed driving chip. The first end of the fifth resistor is connected with the output low-end signal pin of the high-speed driving chip, and the second end of the fifth resistor is connected with the second end of the fourth resistor as the output end of the isolation driving circuit.

7. The gallium nitride half-bridge driver circuit of claim 3, wherein, The first protection circuit and the second protection circuit both include: The positive electrode of the diode is grounded, and the negative electrode of the diode is connected with the input end of the protection circuit. The positive electrode of the transient suppression voltage stabilizing diode is connected with the negative electrode of the diode, and the negative electrode of the transient suppression voltage stabilizing diode is grounded. The first end of the sixth resistor is connected with the positive electrode of the transient suppression voltage stabilizing diode as the output end of the protection circuit, and the second end of the sixth resistor is grounded.

8. The gallium nitride half-bridge driver circuit of claim 2, wherein, The types of the first isolation power supply chip, the second isolation power supply chip, the third isolation power supply chip and the fourth isolation power supply chip include B0509-2WR3 and B0505-2WR3.

9. The gallium nitride half-bridge driver circuit of claim 4, wherein, The type of the isolation driving chip includes Nsi6602A and Ucc21520.

10. The gallium nitride half-bridge driver circuit of claim 6, wherein, The type of the high-speed driving chip includes HD1001 and LMG1020.

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