Power tube control circuit and vehicle-mounted charger

Abstract

The utility model discloses a power tube control circuit and a vehicle-mounted charger, and relates to the technical field of electronics, the power tube control circuit is characterized in that a driving module is respectively connected with a voltage regulating module and a grid electrode of a gallium nitride power tube, and the voltage regulating module is also connected with a driving power supply; the voltage regulating module is used for converting a first driving voltage output by the driving power supply into a second driving voltage and transmitting the second driving voltage to the driving module; and the driving module is used for sending a corresponding driving signal to the gallium nitride power tube when receiving the second driving voltage so as to drive the gallium nitride power tube to switch an on-off state. The voltage which is provided by a system or a product and is not matched with the current gallium nitride power tube package is converted into the driving voltage matched with the current gallium nitride power tube package, so that the gallium nitride power tube can work normally, and the situation that the gallium nitride power tube cannot be used in the same system or product due to different packages is avoided.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to a power tube control circuit and a vehicle charger. Background Art

[0002] With the continuous development of new energy vehicle technology, people's demand for charging new energy vehicles is getting higher and higher. In order to improve the endurance of new energy vehicles, the on-board chargers of new energy vehicles need a higher power density to quickly charge the vehicles. The traditional silicon power tubes can no longer meet the current high power density requirements of on-board chargers. In response to the above needs, gallium nitride power tubes are gradually being used to replace silicon power tubes to improve the power density of on-board chargers. However, in actual situations, there are many packages of silicon nitride power tubes, and each package can be used in on-board chargers, but the required driving voltages of each package are different. It is impossible to directly replace gallium nitride power tubes of multiple different packages in a system or product with a specific driving voltage. The inventory management and supply chain smoothness of the manufacturer are required to be high. If the inventory of a certain package is insufficient or the supply chain is interrupted, it may cause a certain on-board charger product to be unable to be produced, which will cause a lot of economic losses. Utility Model Content

[0003] The main purpose of the present application is to provide a power tube control circuit and a vehicle charger, aiming to solve the technical problem of how to make a gallium nitride power tube of a specific package work normally in a system or product that provides an unmatched driving voltage.

[0004] To achieve the above object, an embodiment of the present application provides a power tube control circuit, the power tube control circuit comprising:

[0005] The driving module is respectively connected to the voltage regulating module and the gate of the gallium nitride power tube, and the voltage regulating module is also connected to the driving power supply;

[0006] The voltage regulating module is used to convert the first driving voltage output by the driving power supply into a second driving voltage, and transmit the second driving voltage to the driving module;

[0007] The driving module is used to send a corresponding driving signal to the gallium nitride power tube when receiving the second driving voltage, so as to drive the gallium nitride power tube to switch the on-off state.

[0008] In one embodiment, the voltage regulating module includes: a first resistor, a second resistor, a first voltage stabilizing diode, a first capacitor and an N-type transistor;

[0009] The first end of the first resistor is connected to the driving power supply, and the second end of the first resistor is respectively connected to the first end of the second resistor and the collector of the N-type transistor; the second end of the second resistor is respectively connected to the base of the N-type transistor and the cathode of the first Zener diode; the emitter of the N-type transistor is respectively connected to the first end of the first capacitor and the driving side power supply end of the driving module; the second end of the first capacitor and the anode of the first Zener diode are grounded.

[0010] In one embodiment, the driving module includes: a second capacitor, a third resistor, a fourth resistor and an isolation driver;

[0011] The driving side power supply end of the isolation driver is connected to the voltage regulating module, the driving output end of the isolation driver is connected to the gate of the gallium nitride power tube, the control side power supply end of the isolation driver is respectively connected to the first end of the second capacitor and the control side power supply; the second end of the second capacitor is grounded; the control input end of the isolation driver is respectively connected to the second end of the third resistor and the first end of the fourth resistor, the first end of the third resistor is connected to the control signal source, and the second end of the fourth resistor is grounded.

[0012] In one embodiment, the power tube control circuit further includes: a switch speed regulation module;

[0013] The first end of the switch speed regulating module is connected to the driving output end of the driving module, and the second end of the switch speed regulating module is connected to the gate of the gallium nitride power tube;

[0014] The switch speed regulation module is used to send a corresponding speed regulation driving signal to the gallium nitride power tube when receiving the driving signal, so as to adjust the speed of switching the on and off states of the gallium nitride power tube.

[0015] In one embodiment, the switch speed regulation module includes: a fifth resistor, a sixth resistor and a Schottky diode;

[0016] The first end of the fifth resistor is connected to the driving output end of the driving module and the first end of the sixth resistor, the second end of the fifth resistor is connected to the anode of the Schottky diode and the gate of the gallium nitride power tube; the second end of the sixth resistor is connected to the cathode of the Schottky diode.

[0017] In one embodiment, the power tube control circuit further includes: a voltage clamping module;

[0018] The first end of the voltage clamping module is connected to the second end of the switch speed regulating module, and the second end of the voltage clamping module is connected to the gate of the gallium nitride power tube;

[0019] The voltage clamping module is used to clamp the high level voltage of the speed regulating driving signal transmitted to the gallium nitride power tube to a preset on-voltage corresponding to the gallium nitride power tube, and to clamp the low level voltage of the speed regulating driving signal to a preset off-voltage corresponding to the gallium nitride power tube.

[0020] In one embodiment, the voltage clamping module includes: a third capacitor, a seventh resistor, a second voltage zener diode and a third voltage zener diode;

[0021] The first end of the third capacitor is respectively connected to the first end of the seventh resistor and the second end of the switch speed control module, and the second end of the third capacitor is respectively connected to the second end of the seventh resistor, the cathode of the second voltage regulator diode and the gate of the gallium nitride power tube; the anode of the second voltage regulator diode is connected to the anode of the third voltage regulator diode; and the cathode of the third voltage regulator diode is grounded.

[0022] In one embodiment, the power tube control circuit further includes: a filtering module;

[0023] The first end of the filter module is connected to the second end of the voltage clamp module, and the second end of the filter module is connected to the gate of the gallium nitride power tube;

[0024] The filtering module is used to filter the received speed regulating driving signal and transmit the filtered speed regulating driving signal to the gallium nitride power tube.

[0025] In one embodiment, the filtering module includes: an eighth resistor, a fourth capacitor and a magnetic bead;

[0026] The first end of the magnetic bead is connected to the second end of the voltage clamping module, and the second end of the magnetic bead is respectively connected to the first end of the eighth resistor, the first end of the fourth capacitor and the gate of the gallium nitride power tube; the second end of the eighth resistor and the second end of the fourth capacitor are grounded.

[0027] In addition, to achieve the above objectives, the present application also provides a vehicle charger, which adopts the power tube control circuit described above.

[0028] The embodiment of the present application provides a power tube control circuit and a vehicle charger, wherein the power tube control circuit comprises: the driving module is respectively connected to the voltage regulating module and the gate of the gallium nitride power tube, and the voltage regulating module is also connected to the driving power supply; the voltage regulating module is used to convert the first driving voltage output by the driving power supply into a second driving voltage, and transmit the second driving voltage to the driving module; the driving module is used to send a corresponding driving signal to the gallium nitride power tube when receiving the second driving voltage, so as to drive the gallium nitride power tube to switch the on-off state. By converting the voltage provided in the system or product that does not match the current gallium nitride power tube package into the driving voltage that matches the current gallium nitride power tube package, the gallium nitride power tube can work normally, avoiding the gallium nitride power tube from being unable to be used in the same system or product due to different gallium nitride power tube packages. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0030] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0031] Figure 1 A structural connection diagram provided for the first embodiment of the power tube control circuit of the present application;

[0032] Figure 2 A circuit connection diagram provided for the second embodiment of the power tube control circuit of the present application;

[0033] Figure 3 This is a circuit connection diagram provided for Embodiment 3 of the power tube control circuit of the present application.

[0034] The purpose, features and advantages of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0035] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0036] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0037] The main solution of the present application is: a voltage regulating module is set between the driving module of the gallium nitride power tube and the driving power supply for providing the driving voltage, and the first driving voltage output by the driving power supply that does not match the current gallium nitride power tube package is converted into a second driving voltage that matches the current gallium nitride power tube package, so that the gallium nitride power tube in the current package can be driven to work by the driving voltage that does not match the current package.

[0038] At present, in order to improve the power density of on-board chargers, the power devices inside the on-board chargers have been gradually replaced by silicon power tubes instead of silicon nitride power tubes. There are many packages of silicon nitride power tubes, and each package can be used in on-board chargers. However, there are differences in the driving voltage required between the packages. It is impossible to directly replace multiple gallium nitride power tubes with different packages in a system or product with a specific driving voltage. The inventory management and supply chain smoothness of the manufacturer are required to be high. If the inventory of a certain package is insufficient or the supply chain is interrupted, it may cause a certain on-board charger product to be unable to be produced, which will cause a lot of economic losses. Therefore, how to make the gallium nitride power tube with a specific package work normally in a system or product that provides an unmatched driving voltage is a problem that needs to be solved urgently.

[0039] The present application converts a voltage provided in a system or product that does not match the current GaN power tube package into a driving voltage that matches the current GaN power tube package, so that the GaN power tube can work normally, thereby avoiding the inability to use the GaN power tube in the same system or product due to different packaging.

[0040] Based on this, the present application proposes a power tube control circuit of the first embodiment, please refer to Figure 1 , the power tube control circuit includes: a driving module 10 and a voltage regulating module 20;

[0041] The driving module 10 is respectively connected to the voltage regulating module 20 and the gate of the GaN power tube FET, and the voltage regulating module 20 is also connected to the driving power supply U1;

[0042] The voltage regulating module 20 is used to convert the first driving voltage output by the driving power supply U1 into a second driving voltage, and transmit the second driving voltage to the driving module 10;

[0043] The driving module 10 is used to send a corresponding driving signal to the GaN power tube FET when receiving the second driving voltage, so as to drive the GaN power tube FET to switch the on-off state.

[0044] It should be understood that as the power density requirements of on-board chargers for new energy vehicles are getting higher and higher, traditional silicon power tubes can no longer meet the power density requirements of current on-board chargers. As a new type of semiconductor power tube, gallium nitride power tubes have many advantages such as small size, fast response speed, low on-resistance, low power loss and high power density, and are gradually replacing traditional silicon power tubes.

[0045] It should be noted that, in actual situations, silicon nitride power tubes have a variety of packages, such as packages with a required driving voltage of 12V / 0V (standard on-voltage / off-voltage), packages with a required driving voltage of 6V / -3V, etc. Since the functions of these gallium nitride power tubes in different packages are basically the same, they can be replaced with each other in theory. For car charger manufacturers, manufacturers generally only purchase gallium nitride power tubes in a variety of packages to facilitate the production of a variety of car chargers to meet the complex and diverse needs of customers, avoid supply chain disruptions and reduce costs. However, due to the different driving voltages of gallium nitride power tubes in different packages, gallium nitride power tubes in different packages cannot be directly replaced in the same product that provides a specific driving voltage. If there is a supply chain interruption, such products cannot be produced normally, which will cause a lot of economic losses.

[0046] It is easy to understand that in this embodiment, the first driving voltage refers to the driving voltage that can be provided by the driving power supply in the car charger or other products required by the current user, and the second driving voltage refers to the driving voltage required by the currently packaged gallium nitride power tube. In a specific implementation, the voltage regulating module 20 can regulate the first driving voltage output by the driving power supply U1, thereby adjusting the first driving voltage that does not match the current gallium nitride power tube FET packaging requirement to a second driving voltage that matches the current gallium nitride power tube FET packaging requirement, and output the second driving voltage to the driving module 10. The driving module 10 can generate a corresponding driving signal based on the received second driving voltage, and transmit the driving signal to the gate of the gallium nitride power tube FET to drive the packaged gallium nitride power tube FET to work normally.

[0047] It is worth noting that in this embodiment, the driving signal may be a PWM signal, and the high level and low level of the driving signal may control the currently packaged gallium nitride power tube FET to enter a fully on state and a fully off state, respectively. For example, if the driving voltage required by the currently packaged gallium nitride power tube FET is 12V / 0V, the high level voltage of the driving signal may be 12V, and correspondingly, the low level voltage of the driving signal may be 0V.

[0048] The embodiment of the present application provides a power tube control circuit, the power tube control circuit comprising: the driving module is respectively connected to the voltage regulating module and the gate of the gallium nitride power tube, the voltage regulating module is also connected to the driving power supply; the voltage regulating module is used to convert the first driving voltage output by the driving power supply into a second driving voltage, and transmit the second driving voltage to the driving module; the driving module is used to send a corresponding driving signal to the gallium nitride power tube when receiving the second driving voltage, so as to drive the gallium nitride power tube to switch the on-off state. By converting the voltage provided in the system or product that does not match the current gallium nitride power tube package into the driving voltage that matches the current gallium nitride power tube package, the gallium nitride power tube can work normally, avoiding the gallium nitride power tube from being unable to be used in the same system or product due to different packages.

[0049] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as those in the above-mentioned embodiment 1 can refer to the above introduction, and will not be repeated later. Figure 2 , the voltage regulating module 20 includes: a first resistor R1, a second resistor R2, a first voltage stabilizing diode Dw1, a first capacitor C1 and an N-type transistor Qn;

[0050] The first end of the first resistor R1 is connected to the driving power supply U1, and the second end of the first resistor R1 is respectively connected to the first end of the second resistor R2 and the collector of the N-type transistor Qn; the second end of the second resistor R2 is respectively connected to the base of the N-type transistor Qn and the cathode of the first voltage-stabilizing diode Dw1; the emitter of the N-type transistor Qn is respectively connected to the first end of the first capacitor C1 and the driving side power supply end of the driving module 10; the second end of the first capacitor C1 and the anode of the first voltage-stabilizing diode Dw1 are grounded.

[0051] It is easy to understand that in this embodiment, the first resistor R1, the second resistor R2 and the first voltage zener diode Dw1 are connected in series between the driving power supply U1 and the ground line, the first voltage zener diode Dw1 is reversely conducted to form a fixed voltage drop value, and the remaining part of the first driving voltage output by the driving power supply U1 is divided between the first resistor R1 and the second resistor R2. Due to the fixed voltage drop value generated by the reverse conduction of the first voltage zener diode Dw1, the voltage at the base of the N-type transistor Qn is stabilized near the above-mentioned fixed voltage drop value, the N-type transistor Qn is turned on and generates a second driving voltage at the emitter, that is, the driving side power supply end of the driving module 10 receives the second driving voltage.

[0052] Among them, the first capacitor C1 is used to filter the second driving voltage received by the driving side power supply end of the driving module 10. In this embodiment, if the resistance value of the first resistor R1 can be adjusted to adjust the second driving voltage generated at the emitter of the N-type transistor Qn. If the first driving voltage is 12V, the second driving voltage is 9V, and the voltage drop value generated by the reverse conduction of the first voltage stabilizing diode Dw1 is 9.6V, then the resistance value of the first resistor R1 can be 1kΩ, and the capacitance value of the first capacitor C1 can be 1uf.

[0053] Furthermore, in this embodiment, the driving module 10 includes: a second capacitor C2, a third resistor R3, a fourth resistor R4 and an isolation driver IDR;

[0054] The driving side power supply end of the isolation driver IDR is connected to the voltage regulating module 20, the driving output end of the isolation driver IDR is connected to the gate of the gallium nitride power tube FET, the control side power supply end of the isolation driver IDR is respectively connected to the first end of the second capacitor C2 and the control side power supply U2; the second end of the second capacitor C2 is grounded; the control input end of the isolation driver IDR is respectively connected to the second end of the third resistor R3 and the first end of the fourth resistor R4, the first end of the third resistor R3 is connected to the control signal source U3, and the second end of the fourth resistor R4 is grounded.

[0055] It should be noted that in this embodiment, since the analog current in the entire circuit is large, an isolation driver IDR can be used to electrically isolate the drive side circuit and the control side circuit in the drive module 10 to prevent the noise or interference signal of the high-voltage drive side circuit from being transmitted to the low-voltage control side circuit, thereby improving the stability and reliability of the entire power module.

[0056] It is easy to understand that the driving side of the isolation driver IDR is respectively connected to the voltage regulating module 20 and the gate of the gallium nitride power tube FET, and the control side of the isolation driver IDR is respectively connected to the control side power supply U2 and the control signal source U3. The control side power supply U2 is used to output a low-voltage control side power supply voltage to support the control side circuit to work, and the second capacitor C2 is used to filter the control side power supply voltage, and the filtered control side power supply voltage is transmitted to the control side power supply end of the isolation driver IDR. The control signal source U3 is used to generate and output a control signal, and the control signal is a PWM signal, which is transmitted to the control input end of the isolation driver IDR. When the control side power supply end of the isolation driver IDR receives the control side power supply voltage, a corresponding drive signal can be generated based on the PWM signal received at the control input end and the second drive voltage received at the power side power supply end, and sent to the gate of the gallium nitride power tube FET through the drive output end to control the switching of the on-off state of the gallium nitride power tube FET. When the control signal is at a high level, the driving output end of the isolation driver IDR outputs a high-level driving signal, and the gallium nitride power tube FET enters the on state; when the control signal is at a low level, the driving output end of the isolation driver IDR outputs a low-level driving signal, and the gallium nitride power tube FET enters the off state, and the high and low levels of the driving signal are controlled by the voltage value of the second driving voltage received by the isolation driver IDR.

[0057] It should be noted that, in the present embodiment, the third resistor R3 and the fourth resistor R4 are connected in series between the control signal source U3 and the ground line, so as to limit the current of the control signal.

[0058] Based on the first embodiment and / or the second embodiment of the present application, in the third embodiment of the present application, the same or similar contents as those of the above-mentioned first and second embodiments can refer to the above introduction, and will not be repeated later. Figure 3 , the power tube control circuit also includes: a switch speed regulation module 30;

[0059] The first end of the switch speed regulating module 30 is connected to the driving output end of the driving module 10, and the second end of the switch speed regulating module 30 is connected to the gate of the gallium nitride power tube FET;

[0060] The switch speed regulating module 30 is used to send a corresponding speed regulating driving signal to the GaN power tube FET when receiving the driving signal, so as to adjust the speed of switching the GaN power tube FET on and off.

[0061] It should be noted that the driving signal is formed based on the control signal output by the control signal source U3 combined with the received second driving voltage, and the driving signal is actually a PWM signal. In this embodiment, a switch speed control module 30 can also be set between the driving module 10 and the gallium nitride power tube FET to adjust the rising edge time and the falling edge time of the driving signal transmitted by the driving module 10, and transmit the speed control driving signal generated after the adjustment to the gate of the gallium nitride power tube FET, so that the switching speed of the gallium nitride power tube FET from the on state to the off state or from the off state to the on state can be adjusted, that is, the speed of switching the on-off state of the gallium nitride power tube FET is adjusted. The above-mentioned switch speed control module 30 is specifically arranged between the driving output end of the isolation driver IDR and the gate of the gallium nitride power tube FET. Since the on-off state switching speed of the gallium nitride power tube FET can be adjusted, the peak current generated by the gallium nitride power tube FET when the on-off state is switched can be effectively limited to improve the service life of the gallium nitride power tube FET.

[0062] Further, in this embodiment, the switch speed regulation module 30 includes: a fifth resistor R5, a sixth resistor R6 and a Schottky diode Dx;

[0063] The first end of the fifth resistor R5 is connected to the driving output end of the driving module 10 and the first end of the sixth resistor R6, the second end of the fifth resistor R5 is connected to the anode of the Schottky diode Dx and the gate of the gallium nitride power tube FET; the second end of the sixth resistor R6 is connected to the cathode of the Schottky diode Dx.

[0064] It is easy to understand that in this embodiment, since the Schottky diode Dx has the characteristics of low forward voltage drop and short reverse recovery time, it can ensure that the high-frequency PWM signal maintains a small distortion during the rising and falling edges, so that the waveform of the PWM signal is more stable. The drive signal is essentially a PWM signal, so the structure composed of the fifth resistor R5, the sixth resistor R6 and the Schottky diode Dx can effectively adjust the rising edge time and the falling edge time of the drive signal output by the isolation driver IDR, thereby forming a more ideal speed-adjusting drive signal for level rise or fall. Among them, the rising edge time and the falling edge time of the drive signal can be adjusted to the required time mainly by changing the resistance values ​​of the fifth resistor R5 and the sixth resistor R6, thereby forming a speed-adjusting drive signal. Preferably, if the second drive voltage is 9V, the resistance value of the fifth resistor R5 can be 2.5Ω, and the resistance value of the sixth resistor R6 can be 5 ohms.

[0065] Furthermore, in this embodiment, the power tube control circuit further includes: a voltage clamping module 40;

[0066] The first end of the voltage clamping module 40 is connected to the second end of the switch speed regulating module 30, and the second end of the voltage clamping module 40 is connected to the gate of the gallium nitride power tube FET;

[0067] The voltage clamping module 40 is used to stabilize the received speed regulating driving signal and transmit the stabilized speed regulating driving signal to the gallium nitride power tube FET.

[0068] The voltage clamping module 40 is used to clamp the high level voltage of the speed regulating driving signal transmitted to the GaN power tube FET to a preset on-voltage corresponding to the GaN power tube FET, and to clamp the low level voltage of the speed regulating driving signal to a preset off-voltage corresponding to the GaN power tube FET.

[0069] It should be noted that the preset on-voltage refers to a preset voltage corresponding to the fully on-state of the GaN power tube, and the preset off-voltage refers to a preset voltage corresponding to the fully off-state of the GaN power tube. The preset on-voltage and the preset off-voltage can be set according to the driving voltage required by the current packaging of the GaN power tube FET. In this embodiment, in order to improve the stability of the GaN power tube FET switching on and off, a voltage clamping module 40 can also be provided between the driving module 10 and the GaN power to clamp the high level and low level of the driving signal output by the driving module 10, or the high level and low level of the speed regulating driving signal output by the switch speed regulating module 30. When the GaN power tube FET receives a high-level driving signal or a speed regulating driving signal, it can stably receive the preset on-voltage and enter the fully on-state, and when it receives a low-level driving signal or a speed regulating driving signal, it can stably receive the preset off-voltage and enter the fully off-state, so that the GaN power tube FET can stably and correctly switch on and off.

[0070] It is worth noting that if a switch speed regulating module 30 is further provided between the driving module 10 and the GaN power tube FET, the voltage clamping module 40 can be specifically provided between the switch speed regulating module 30 and the gate of the GaN power tube FET.

[0071] Further, in this embodiment, the voltage clamping module 40 includes: a third capacitor C3, a seventh resistor R7, a second voltage zener diode Dw2 and a third voltage zener diode Dw3;

[0072] The first end of the third capacitor C3 is respectively connected to the first end of the seventh resistor R7 and the second end of the switch speed control module 30, and the second end of the third capacitor C3 is respectively connected to the second end of the seventh resistor R7, the cathode of the second voltage regulator diode Dw2 and the gate of the gallium nitride power tube FET; the anode of the second voltage regulator diode Dw2 is connected to the anode of the third voltage regulator diode Dw3; the cathode of the third voltage regulator diode Dw3 is grounded.

[0073] It is easy to understand that in this embodiment, the second voltage zener diode Dw2 and the third voltage zener diode Dw3 are reversely connected in series between the gate and the ground of the gallium nitride power tube FET, and the third capacitor C3 and the seventh resistor R7 form a parallel RC circuit, which can be charged and discharged following the high and low level changes of the drive signal or the speed regulation drive signal. The structure formed by the above-mentioned devices is used to clamp the voltage received at the gate of the gallium nitride power tube FET. In the case where the current package of the gallium nitride power tube FET is 6V / -3V, the voltage drop formed by the second voltage zener diode Dw2 and the third voltage zener diode Dw3 can be 6V, and the maximum voltage across the third capacitor C3 can be 3V. If the high level of the current driving signal is 9V, when receiving a high-level driving signal or a driving speed regulation signal, the third capacitor C3 is charged, and the first voltage zener diode Dw1 and the second voltage zener diode Dw2 can clamp the voltage at the gate of the gallium nitride power tube FET to 6V, so that the gallium nitride power tube FET is stably in a fully turned-on state; if the low level of the current driving signal is 0V, since the voltages on both sides of the third capacitor C3 cannot change suddenly, the potential between the third capacitor C3 and the gate of the gallium nitride power tube FET is at +3V, and the first voltage zener diode Dw1 and the second voltage zener diode Dw2 will still generate a voltage drop of 6V, and the two work together to clamp the voltage at the gate of the gallium nitride power tube FET to -3V, so that the gallium nitride power tube FET is stably in a fully turned-off state.

[0074] Furthermore, in this embodiment, the power tube control circuit further includes: a filter module 50;

[0075] The first end of the filter module 50 is connected to the second end of the voltage clamp module 40, and the second end of the filter module 50 is connected to the gate of the gallium nitride power tube FET;

[0076] The filtering module 50 is used to filter the received speed regulating driving signal and transmit the filtered speed regulating driving signal to the gallium nitride power tube FET.

[0077] It should be noted that, in order to reduce the influence of noise and other interference signals in the circuit on the on-off state of the GaN power tube FET, a filter module 50 is also provided between the driving module 10 and the GaN power tube FET to filter the driving signal or the speed regulating driving signal after the voltage stabilization process. If there are other functional modules between the driving module 10 and the GaN power tube FET, such as the switch speed regulating module 30, the filter module 50 is arranged close to the gate of the GaN power tube FET, that is, it can be understood that no matter how many other functional modules are between the driving module 10 and the GaN power tube FET, the filter module 50 is always connected to the gate of the GaN power tube FET, so that the best filtering effect can be achieved.

[0078] Furthermore, in this embodiment, the filtering module 50 includes: an eighth resistor R8, a fourth capacitor C4 and a magnetic bead L;

[0079] The first end of the magnetic bead L is connected to the second end of the voltage clamping module 40, and the second end of the magnetic bead L is respectively connected to the first end of the eighth resistor R8, the first end of the fourth capacitor C4 and the gate of the gallium nitride power tube FET; the second end of the eighth resistor R8 and the second end of the fourth capacitor C4 are grounded.

[0080] It should be noted that, in this embodiment, the eighth resistor R8 and the fourth capacitor C4 form a parallel RC circuit, which is connected between the gate and the ground of the gallium nitride power tube FET to filter out high-frequency noise in the circuit. The magnetic bead L can suppress electromagnetic interference, transplant high-frequency noise and peak current in the circuit, and prevent the generation of transient current caused by electrostatic discharge.

[0081] In addition, to achieve the above purpose, the embodiment of the present application also proposes a vehicle charger, which adopts all the embodiments of the power tube control circuit described above. Compared with the prior art, the beneficial effects of the vehicle charger provided by the embodiment of the present application are the same as the beneficial effects of the power tube control circuit provided by the above embodiment, and the other technical features of the vehicle charger are the same as the features disclosed in the above embodiment, which will not be repeated here.

[0082] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent processing scope of the present application.

Claims

1. A power tube control circuit, characterized in that: The power tube control circuit includes: a driving module and a voltage regulating module; The driving module is respectively connected to the voltage regulating module and the gate of the gallium nitride power tube, and the voltage regulating module is also connected to the driving power supply; The voltage regulating module is used to convert the first driving voltage output by the driving power supply into a second driving voltage, and transmit the second driving voltage to the driving module; The driving module is used to send a corresponding driving signal to the gallium nitride power tube when receiving the second driving voltage, so as to drive the gallium nitride power tube to switch the on-off state.

2. The power tube control circuit according to claim 1, characterized in that: The voltage regulating module comprises: a first resistor, a second resistor, a first voltage stabilizing diode, a first capacitor and an N-type transistor; The first end of the first resistor is connected to the driving power supply, and the second end of the first resistor is respectively connected to the first end of the second resistor and the collector of the N-type transistor; the second end of the second resistor is respectively connected to the base of the N-type transistor and the cathode of the first Zener diode; the emitter of the N-type transistor is respectively connected to the first end of the first capacitor and the driving side power supply end of the driving module; the second end of the first capacitor and the anode of the first Zener diode are grounded.

3. The power tube control circuit according to claim 1, characterized in that: The driving module includes: a second capacitor, a third resistor, a fourth resistor and an isolation driver; The driving side power supply end of the isolation driver is connected to the voltage regulating module, the driving output end of the isolation driver is connected to the gate of the gallium nitride power tube, the control side power supply end of the isolation driver is respectively connected to the first end of the second capacitor and the control side power supply; the second end of the second capacitor is grounded; the control input end of the isolation driver is respectively connected to the second end of the third resistor and the first end of the fourth resistor, the first end of the third resistor is connected to the control signal source, and the second end of the fourth resistor is grounded.

4. The power tube control circuit according to claim 1, characterized in that: The power tube control circuit also includes: a switch speed regulation module; The first end of the switch speed regulating module is connected to the driving output end of the driving module, and the second end of the switch speed regulating module is connected to the gate of the gallium nitride power tube; The switch speed regulation module is used to send a corresponding speed regulation driving signal to the gallium nitride power tube when receiving the driving signal, so as to adjust the speed of switching the on and off states of the gallium nitride power tube.

5. The power tube control circuit according to claim 4, characterized in that: The switch speed regulation module includes: a fifth resistor, a sixth resistor and a Schottky diode; The first end of the fifth resistor is connected to the driving output end of the driving module and the first end of the sixth resistor, the second end of the fifth resistor is connected to the anode of the Schottky diode and the gate of the gallium nitride power tube; the second end of the sixth resistor is connected to the cathode of the Schottky diode.

6. The power tube control circuit according to claim 4, characterized in that: The power tube control circuit further includes: a voltage clamping module; The first end of the voltage clamping module is connected to the second end of the switch speed regulating module, and the second end of the voltage clamping module is connected to the gate of the gallium nitride power tube; The voltage clamping module is used to clamp the high level voltage of the speed regulating driving signal transmitted to the gallium nitride power tube to a preset on-voltage corresponding to the gallium nitride power tube, and to clamp the low level voltage of the speed regulating driving signal to a preset off-voltage corresponding to the gallium nitride power tube.

7. The power tube control circuit according to claim 6, characterized in that: The voltage clamping module includes: a third capacitor, a seventh resistor, a second voltage stabilizing diode and a third voltage stabilizing diode; The first end of the third capacitor is respectively connected to the first end of the seventh resistor and the second end of the switch speed control module, and the second end of the third capacitor is respectively connected to the second end of the seventh resistor, the cathode of the second voltage regulator diode and the gate of the gallium nitride power tube; the anode of the second voltage regulator diode is connected to the anode of the third voltage regulator diode; and the cathode of the third voltage regulator diode is grounded.

8. The power tube control circuit according to claim 6, characterized in that: The power tube control circuit further includes: a filter module; The first end of the filter module is connected to the second end of the voltage clamp module, and the second end of the filter module is connected to the gate of the gallium nitride power tube; The filtering module is used to filter the received speed regulating driving signal and transmit the filtered speed regulating driving signal to the gallium nitride power tube.

9. The power tube control circuit according to claim 8, characterized in that: The filtering module comprises: an eighth resistor, a fourth capacitor and a magnetic bead; The first end of the magnetic bead is connected to the second end of the voltage clamping module, and the second end of the magnetic bead is respectively connected to the first end of the eighth resistor, the first end of the fourth capacitor and the gate of the gallium nitride power tube; the second end of the eighth resistor and the second end of the fourth capacitor are grounded.

10. A vehicle charger, characterized in that: The on-board charger adopts the power tube control circuit as described in any one of claims 1-9.

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