Power protection circuit of gallium nitride rapid charging power supply

Abstract

The invention specifically relates to a power protection circuit of a gallium nitride rapid charging power supply, and the circuit comprises a gallium nitride mosfet which is used for controlling whether a power supply circuit is switched on or not and protecting the power supply circuit; the sampling circuit is used for collecting the state of the power supply circuit and feeding back the state to the main control chip, the output end of the main control chip is electrically connected with the grid electrode of the gallium nitride mosfet, and in the low-frequency working state, the main control chip outputs a control signal to the grid electrode of the gallium nitride mosfet according to the feedback of the sampling circuit or outputs a control signal to the grid electrode of the gallium nitride mosfet according to a user pre-program. The gallium nitride mosfet driving circuit further comprises a first-class auxiliary circuit, the output end of the first-class auxiliary circuit is electrically connected with the grid electrode of the gallium nitride mosfet, and in the high-frequency working state, the main control chip and the first-class auxiliary circuit jointly output control signals to the grid electrode of the gallium nitride mosfet in a time domain sharing mode according to feedback of the sampling circuit. Or the control signal is output to the grid electrode of the gallium nitride mosfet together with the first-class auxiliary circuit in a time domain sharing mode according to a user pre-program.

Description

Technical Field

[0001] The present invention belongs to the field of fast charging, and in particular relates to a power protection circuit of a gallium nitride fast charging power supply. Background Art

[0002] The switching speed of GaN MOSFET is faster than that of traditional silicon-based MOSFET. In high-frequency applications, GaN MOSFET has greater advantages. This is because GaN material has higher electron mobility and saturation electron velocity, which enables GaN MOSFET to switch faster. Therefore, the driving circuit design of GaN MOSFET is also an important factor affecting its switching speed. However, if the driving circuit frequency of the GaN MOSFET is to be higher, a control device with better performance and higher frequency is generally required, which makes the cost of the control device higher. For example, GaN is a high-frequency device that can run at a very high switching frequency, reaching a switching frequency of 1000K. However, some high-performance MOSFET driving circuits, such as Jingfeng BP2628, have a maximum driving switching frequency of only 500K. Although the performance of Jingfeng BP2628 chips is already very good, there is no problem in using them in traditional silicon-based MOSFET switches, and there is no problem in some GaN MOSFET applications (because the driving switching frequency does not need to reach 500K in some GaN MOSFET applications), it cannot meet the requirements of GaN MOSFET applications with slightly higher requirements (the driving switching frequency is required to be between 500K-1000K, or even above 1000K). Summary of the invention

[0003] The object of the present invention is to provide a power protection circuit for a gallium nitride fast charging power supply to solve the problems raised in the above background technology.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0005] The power protection circuit of the GaN fast charging power supply includes a GaN MOSFET, the non-control electrode of the GaN MOSFET is electrically connected to the power circuit, and is used to control whether the power circuit is turned on and protect the power circuit;

[0006] The power supply circuit is electrically connected to the sampling circuit, and the main control chip is electrically connected to the sampling circuit. The sampling circuit is used to collect the state of the power supply circuit and feed it back to the main control chip. The output end of the main control chip is electrically connected to the gate of the gallium nitride MOSFET. In the low-frequency working state, the main control chip outputs a control signal to the gate of the gallium nitride MOSFET according to the feedback of the sampling circuit or outputs a control signal to the gate of the gallium nitride MOSFET according to a user's pre-programmed program. The main control chip also includes a first type of auxiliary circuit, and the output end of the first type of auxiliary circuit is electrically connected to the gate of the gallium nitride MOSFET. In the high-frequency working state, the main control chip and the first type of auxiliary circuit use a time-domain method to jointly output a control signal to the gate of the gallium nitride MOSFET according to the feedback of the sampling circuit, or use a time-domain method to jointly output a control signal to the gate of the gallium nitride MOSFET according to the user's pre-programmed program.

[0007] Preferably, the minimum period of the gate output control signal of the main control chip to the gallium nitride MOSFET is t, and the maximum frequency is 1 / t. The main control chip and the first type of auxiliary circuit jointly output the gate control signal of the gallium nitride MOSFET in a time domain manner, then the minimum period of the gate output control signal of the gallium nitride MOSFET is t / 2, and the maximum frequency is 2 / t.

[0008] Preferably, a second type of auxiliary circuit is also included, and the output end of the second type of auxiliary circuit is electrically connected to the gate of the gallium nitride MOSFET. In the high-frequency working state, the main control chip outputs a control signal to the gate of the gallium nitride MOSFET in a time-domain manner together with the first type of auxiliary circuit and / or the second type of auxiliary circuit according to the feedback of the sampling circuit, or outputs a control signal to the gate of the gallium nitride MOSFET in a time-domain manner together with the first type of auxiliary circuit and / or the second type of auxiliary circuit according to the user's pre-programmed program.

[0009] Preferably, the original main control chip has a minimum period of t and a maximum frequency of 1 / t for the gate output control signal of the gallium nitride mosfet, and the main control chip and the first and second auxiliary circuits use a time domain method to jointly output the gate control signal of the gallium nitride mosfet. Then, the minimum period of the gate output control signal of the gallium nitride mosfet is t / 3, and the maximum frequency is 3 / t.

[0010] Preferably, the second type of auxiliary circuit uses a low-frequency driver chip whose performance frequency is inferior to that of a traditional silicon-based MOSFET or a non-driver chip that can output a control signal in a high-frequency working state.

[0011] Preferably, the sampling circuit specifically includes a voltage-dividing resistor circuit, a filtering amplifier circuit and an analog-to-digital conversion circuit which are electrically connected in sequence. Preferably, the main control chip adopts a traditional silicon-based MOSFET low-frequency driver chip.

[0012] Preferably, the low-frequency working state, that is, the working switching frequency required by the gallium nitride MOSFET is lower than the rated frequency output by the main control chip.

[0013] Preferably, the first type of auxiliary circuit uses a low-frequency driver chip of a traditional silicon-based mosfet or a low-frequency driver chip whose performance frequency is inferior to that of a traditional silicon-based mosfet, and both the first type of auxiliary circuit and the main control chip use working chips that can be modified and programmed.

[0014] The high-frequency working state means that the working switching frequency required by the GaN MOSFET is not lower than the rated frequency output by the main control chip.

[0015] Beneficial Effects

[0016] In the application of gallium nitride MOSFET, the present application adopts the low-frequency driving chip commonly used in traditional silicon-based MOSFET and / or the low-frequency driving chip with performance frequency slightly lower than that commonly used in traditional silicon-based MOSFET to increase the driving switching frequency, without the need to specially replace the high-performance chip, with lower cost and more flexible control. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a block diagram of the power protection circuit of the GaN fast charging power supply. DETAILED DESCRIPTION

[0018] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0019] Glossary: ​​The gallium nitride MOSFET disclosed in this application is a new type of field effect transistor that utilizes the material gallium nitride. Gallium nitride is a semiconductor material with high electron mobility and high saturation speed, so the gallium nitride MOSFET has high switching speed and efficiency. It is widely used in high-frequency, high-power, high-voltage, and high-current power management and power conversion electronic products, such as fast charging power supplies, wireless charging, inverters, electric vehicles, solar power generation, etc. Due to its high speed and high efficiency, gallium nitride MOSFET plays an important role in improving the performance and efficiency of power systems.

[0020] like Figure 1 The power protection circuit of the gallium nitride fast charging power supply disclosed in the present application includes a gallium nitride mosfet, and the non-control electrode of the gallium nitride mosfet is electrically connected to the power circuit, and is used to control whether the power circuit is turned on and protect the power circuit;

[0021] The power supply circuit is electrically connected to the sampling circuit, and the main control chip is electrically connected to the sampling circuit. The sampling circuit specifically includes a voltage-dividing resistor circuit, a filtering amplifier circuit and an analog-to-digital conversion circuit which are electrically connected in sequence. The voltage-dividing resistor circuit of the power supply is usually implemented by a resistor voltage divider. The resistor voltage divider consists of two or more resistors, and the power supply voltage is divided to the required voltage value in series. The filtering amplifier circuit can be implemented by an amplifier and a filter to filter out the AC component in the power supply voltage. The analog-to-digital conversion circuit can be implemented by an ADC (analog-to-digital converter) to convert the analog voltage into a digital signal. These circuits can be electrically connected through appropriate circuit board design and welding technology.

[0022] The sampling circuit is used to collect the state of the power supply circuit and feed it back to the main control chip. The output end of the main control chip is electrically connected to the gate of the gallium nitride MOSFET. The main control chip of the present application can adopt a low-frequency driving chip commonly used in traditional silicon-based MOSFETs. In the low-frequency working state, the main control chip outputs a control signal to the gate of the gallium nitride MOSFET based on the feedback of the sampling circuit or outputs a control signal to the gate of the gallium nitride MOSFET based on the user's pre-programmed output. The low-frequency working state means that the working switching frequency required by the gallium nitride MOSFET is lower than the rated frequency output by the main control chip. The first type of auxiliary circuit is also included. The output end of the first type of auxiliary circuit The first type of auxiliary circuit of the present application is electrically connected to the gate of the gallium nitride MOSFET. The first type of auxiliary circuit adopts a low-frequency driving chip commonly used in traditional silicon-based MOSFETs or a low-frequency driving chip whose performance frequency is slightly inferior to that of traditional silicon-based MOSFETs. Both the first type of auxiliary circuit and the main control chip adopt working chips that can be modified and programmed. In the high-frequency working state, the main control chip outputs a control signal to the gate of the gallium nitride MOSFET in a time-domain manner together with the first type of auxiliary circuit based on the feedback of the sampling circuit, or outputs a control signal to the gate of the gallium nitride MOSFET in a time-domain manner together with the first type of auxiliary circuit based on the user's pre-programmed program.

[0023] The high-frequency working state means that the working switching frequency required by the GaN MOSFET is not lower than the rated frequency output by the main control chip; for example, the original main control chip outputs a control signal to the gate of the GaN MOSFET with a minimum period of t and a maximum frequency of 1 / t. The gate output control signal of the GaN MOSFET is jointly output by the first type of auxiliary circuit in a time-domain manner. Then, the minimum period of the gate output control signal of the GaN MOSFET is t / 2 and the maximum frequency is 2 / t. If multiple first type auxiliary circuits are used, the maximum frequency can be larger. The gate is controlled by multiple control signals in the time domain, and multiple control signals are used to control the gate in turn. , in order to achieve the purpose of switching the switching state of the transistor or field effect tube (FET); how to distribute these control signals depends on the specific type of electronic equipment and devices used: determine the signal distribution principle: first, it is necessary to determine the principle of signal distribution, signal time domain distribution: according to the principle, each control signal is assigned to a specific time period; gate driver: the gate driver is the circuit responsible for converting the control signal into a voltage suitable for the gate; it usually switches the voltage according to the assigned schedule to control the switching state of the transistor or field effect tube; power supply and grounding: ensure that all control signals get energy from the appropriate power and ground pins.The power protection circuit of the gallium nitride fast charging power supply disclosed in the present application also includes a second type of auxiliary circuit, the output end of the second type of auxiliary circuit is electrically connected to the gate of the gallium nitride mosfet, the second type of auxiliary circuit of the present application adopts a low-frequency driving chip whose performance frequency is inferior to that commonly used in traditional silicon-based mosfet, or adopts a non-driving chip that can output a control signal in a high-frequency working state, such as a fixed crystal oscillator circuit, the second type of auxiliary circuit can adopt a working chip that can be modified and programmed, or a working chip that cannot be programmed, or a non-driving chip that can output a control signal in a high-frequency working state; in the high-frequency working state, the main control chip outputs a control signal to the gate of the gallium nitride mosfet in a time-domain manner together with the first type of auxiliary circuit and / or the second type of auxiliary circuit based on the feedback of the sampling circuit, or adopts a time-domain manner together with the first type of auxiliary circuit and / or the second type of auxiliary circuit based on the user's pre-programmed program. The gate output control signal of the GaN MOSFET is a high-frequency working state, that is, the working switching frequency required by the GaN MOSFET is not lower than the rated frequency output by the main control chip. For example, the original main control chip outputs a control signal of the GaN MOSFET with a minimum period of t and a maximum frequency of 1 / t for the gate. The first and second auxiliary circuits use a time domain method to jointly output a control signal to the gate of the GaN MOSFET. Then, the minimum period of the gate output control signal of the GaN MOSFET is t / 3 and the maximum frequency is 3 / t. Multiple first or second auxiliary circuits can be used, and the maximum frequency can be larger. It can be seen that the present application can increase the driving switching frequency by using low-frequency driving chips commonly used in traditional silicon-based MOSFETs and / or low-frequency driving chips with performance frequencies slightly inferior to those commonly used in traditional silicon-based MOSFETs in the application of GaN MOSFETs. There is no need to specially replace high-performance chips, which is more cost-effective and more flexible in control.

[0024] The embodiments to be protected in this application are:

[0025] The power protection circuit of the GaN fast charging power supply includes a GaN MOSFET, the non-control electrode of the GaN MOSFET is electrically connected to the power circuit, and is used to control whether the power circuit is turned on and protect the power circuit;

[0026] The power supply circuit is electrically connected to the sampling circuit, and the main control chip is electrically connected to the sampling circuit. The sampling circuit is used to collect the state of the power supply circuit and feed it back to the main control chip. The output end of the main control chip is electrically connected to the gate of the gallium nitride MOSFET. In the low-frequency working state, the main control chip outputs a control signal to the gate of the gallium nitride MOSFET according to the feedback of the sampling circuit or outputs a control signal to the gate of the gallium nitride MOSFET according to a user's pre-programmed program. The main control chip also includes a first type of auxiliary circuit, and the output end of the first type of auxiliary circuit is electrically connected to the gate of the gallium nitride MOSFET. In the high-frequency working state, the main control chip and the first type of auxiliary circuit use a time-domain method to jointly output a control signal to the gate of the gallium nitride MOSFET according to the feedback of the sampling circuit, or use a time-domain method to jointly output a control signal to the gate of the gallium nitride MOSFET according to the user's pre-programmed program.

[0027] Preferably, the minimum period of the gate output control signal of the main control chip to the gallium nitride MOSFET is t, and the maximum frequency is 1 / t. The main control chip and the first type of auxiliary circuit jointly output the gate control signal of the gallium nitride MOSFET in a time domain manner, then the minimum period of the gate output control signal of the gallium nitride MOSFET is t / 2, and the maximum frequency is 2 / t.

[0028] Preferably, a second type of auxiliary circuit is also included, and the output end of the second type of auxiliary circuit is electrically connected to the gate of the gallium nitride MOSFET. In the high-frequency working state, the main control chip outputs a control signal to the gate of the gallium nitride MOSFET in a time-domain manner together with the first type of auxiliary circuit and / or the second type of auxiliary circuit according to the feedback of the sampling circuit, or outputs a control signal to the gate of the gallium nitride MOSFET in a time-domain manner together with the first type of auxiliary circuit and / or the second type of auxiliary circuit according to the user's pre-programmed program.

[0029] Preferably, the original main control chip has a minimum period of t and a maximum frequency of 1 / t for the gate output control signal of the gallium nitride mosfet, and the main control chip and the first and second auxiliary circuits use a time domain method to jointly output the gate control signal of the gallium nitride mosfet. Then, the minimum period of the gate output control signal of the gallium nitride mosfet is t / 3, and the maximum frequency is 3 / t.

[0030] Preferably, the second type of auxiliary circuit uses a low-frequency driver chip whose performance frequency is inferior to that of a traditional silicon-based MOSFET or a non-driver chip that can output a control signal in a high-frequency working state.

[0031] Preferably, the sampling circuit specifically includes a voltage-dividing resistor circuit, a filtering amplifier circuit and an analog-to-digital conversion circuit which are electrically connected in sequence. Preferably, the main control chip adopts a traditional silicon-based MOSFET low-frequency driver chip.

[0032] Preferably, the low-frequency working state, that is, the working switching frequency required by the gallium nitride MOSFET is lower than the rated frequency output by the main control chip.

[0033] Preferably, the first type of auxiliary circuit uses a low-frequency driver chip of a traditional silicon-based mosfet or a low-frequency driver chip whose performance frequency is inferior to that of a traditional silicon-based mosfet, and both the first type of auxiliary circuit and the main control chip use working chips that can be modified and programmed.

[0034] The high-frequency working state means that the working switching frequency required by the gallium nitride MOSFET is not lower than the rated frequency output by the main control chip. In addition, the embodiment of the present application also provides a storage medium, which is used to store a computer program, and the computer program is used to execute the functions of the main control chip provided in the above embodiment.

[0035] The embodiment of the present application also provides a computer program product including instructions, which, when executed on a computer, enables the computer to execute the functions of the main control chip provided in the above embodiment.

[0036] It should be noted that each embodiment in this specification is described in a progressive manner, and the same and similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The device and system embodiments described above are only schematic, in which the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative work. The above is only a specific implementation of the present application, but the protection scope of the present application is not limited to this. Any changes or replacements that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in this application should be covered within the protection scope of this application.

Claims

1. A power protection circuit for a gallium nitride fast charging power supply, characterized in that: A gallium nitride MOSFET, wherein the non-control electrode of the gallium nitride MOSFET is electrically connected to a power circuit, and is used to control whether the power circuit is turned on and protect the power circuit; the power circuit is electrically connected to a sampling circuit, and the main control chip is electrically connected to the sampling circuit, the sampling circuit is used to collect the state of the power circuit and feed it back to the main control chip, the output end of the main control chip is electrically connected to the gate of the gallium nitride MOSFET, in a low-frequency working state, the main control chip outputs a control signal to the gate of the gallium nitride MOSFET according to the feedback of the sampling circuit, or outputs a control signal to the gate of the gallium nitride MOSFET according to a user's pre-programmed program, and also includes a first type of auxiliary circuit, the output end of the first type of auxiliary circuit is electrically connected to the gate of the gallium nitride MOSFET, in a high-frequency working state, the main control chip and the first type of auxiliary circuit jointly output a control signal to the gate of the gallium nitride MOSFET in a time-division manner according to the feedback of the sampling circuit, or jointly output a control signal to the gate of the gallium nitride MOSFET in a time-division manner according to the user's pre-programmed program.

2. The power protection circuit of the gallium nitride fast charging power supply according to claim 1, characterized in that: The minimum period of the gate output control signal of the main control chip to the GaN MOSFET is t, and the maximum frequency is 1 / t. The main control chip and the first type of auxiliary circuit jointly output the gate control signal of the GaN MOSFET in a time domain manner. Then, the minimum period of the gate output control signal of the GaN MOSFET is t / 2, and the maximum frequency is 2 / t.

3. The power protection circuit of the gallium nitride fast charging power supply according to claim 1, characterized in that: It also includes a second type of auxiliary circuit, the output end of the second type of auxiliary circuit is electrically connected to the gate of the gallium nitride MOSFET. In the high-frequency working state, the main control chip uses the time domain method to jointly output a control signal to the gate of the gallium nitride MOSFET based on the feedback of the sampling circuit with the first type of auxiliary circuit and / or the second type of auxiliary circuit, or uses the time domain method to jointly output a control signal to the gate of the gallium nitride MOSFET based on the user's pre-programmed program with the first type of auxiliary circuit and / or the second type of auxiliary circuit.

4. The power protection circuit of the gallium nitride fast charging power supply according to claim 3, characterized in that: The original main control chip has a minimum period of t and a maximum frequency of 1 / t for the gate output control signal of the GaN MOSFET. The main control chip and the first and second auxiliary circuits use a time domain method to jointly output the gate control signal of the GaN MOSFET. The minimum period of the gate output control signal of the GaN MOSFET is t / 3 and the maximum frequency is 3 / t.

5. The power protection circuit of the gallium nitride fast charging power supply according to claim 4, characterized in that: The second type of auxiliary circuit uses a low-frequency driver chip whose performance frequency is inferior to that of traditional silicon-based MOSFETs, or a non-driver chip that can output control signals in a high-frequency working state.

6. The power protection circuit of the gallium nitride fast charging power supply according to claim 1, characterized in that: The sampling circuit specifically includes a voltage-dividing resistor circuit, a filtering amplifier circuit and an analog-to-digital conversion circuit which are electrically connected in sequence.

7. The power protection circuit of the gallium nitride fast charging power supply according to claim 1, characterized in that: The main control chip uses a traditional silicon-based MOSFET low-frequency driver chip.

8. The power protection circuit of the gallium nitride fast charging power supply according to claim 1, characterized in that: The low-frequency working state means that the working switching frequency required by the GaN MOSFET is lower than the rated frequency output by the main control chip.

9. The power protection circuit of the gallium nitride fast charging power supply according to claim 1, characterized in that: The first type of auxiliary circuit uses a low-frequency driver chip of a traditional silicon-based mosfet or a low-frequency driver chip whose performance frequency is inferior to that of a traditional silicon-based mosfet. Both the first type of auxiliary circuit and the main control chip use working chips that can be modified and programmed.

10. The power protection circuit of the gallium nitride fast charging power supply according to claim 1, characterized in that: The high-frequency working state means that the working switching frequency required by the GaN MOSFET is not lower than the rated frequency output by the main control chip.

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