Gallium nitride switching power supply based on multiple fast charge protocols

Abstract

The invention relates to a gallium nitride switching power supply based on multiple fast charging protocols. The gallium nitride switching power supply comprises a transformer; a drain electrode of the gallium nitride switch tube is connected with the other end of the primary winding and a source electrode is connected with signal ground; a master control circuit; the gallium nitride driving circuit is connected with the main control circuit and the gallium nitride switching tube; the valley bottom conduction circuit is connected with one end of the auxiliary winding and the main control circuit; an output rectification filter circuit; and the fast charging protocol detection circuit is connected with the output rectification filter circuit. The gallium nitride switching tube is adopted, the critical breakdown voltage is high, and the electron mobility is high; the gallium nitride driving circuit can realize slow opening and quick closing of a gallium nitride switching tube, so that the peak of synchronous rectification of the secondary winding is eliminated; the valley bottom conduction circuit can enable the gallium nitride switching tube to be conducted near the valley bottom, so that the conversion efficiency of the system can be greatly improved, the switching loss is reduced, and the whole circuit reaches a quasi-resonant state; in addition, the fast charging protocol detection circuit can realize multi-protocol fast charging.

Description

Technical Field

[0001] The present invention relates to the field of switching power supplies, and in particular to a gallium nitride switching power supply based on multiple fast charging protocols. Background Art

[0002] A switching power supply is a power supply that achieves power conversion by adjusting the output voltage and current through the rapid switching of switching elements. Currently, most switching power supplies on the market are based on silicon materials, which have the disadvantages of high loss and low performance under high temperature conditions. In addition, most switching power supplies on the market today only support a single fast charging protocol, while some switching power supplies that support multiple fast charging protocols have compatibility issues and efficiency issues with different devices. Summary of the invention

[0003] The present invention provides a gallium nitride switching power supply based on multiple fast charging protocols to solve at least one of the above-mentioned technical problems.

[0004] The technical solution of the present invention to solve the above technical problems is as follows: A gallium nitride switching power supply based on multiple fast charging protocols, comprising:

[0005] An input rectifying and filtering circuit is connected between the AC signal and a common ground, and is used to rectify and filter the AC signal to obtain a DC signal;

[0006] A transformer, comprising a primary winding, an auxiliary winding and a secondary winding, wherein one end of the primary winding is connected to the input rectifying and filtering circuit;

[0007] A gallium nitride switch tube, the gate of which is alternately connected to the first drive signal and the second drive signal, the drain of which is connected to the other end of the primary winding, and the source of which is connected to the signal ground, and is used to slowly turn on under the action of the first drive signal and quickly turn off under the action of the second drive signal, so that the DC signal is converted into a square wave signal in the primary winding, and then the square wave signal in the primary winding is coupled to the auxiliary winding and the secondary winding, so as to generate corresponding auxiliary coupling signals and secondary coupling signals in the auxiliary winding and the secondary winding respectively;

[0008] A high-voltage starting circuit, connected to the input rectifying and filtering circuit, and used for generating a high-voltage starting signal according to the DC signal;

[0009] a power supply circuit, connected to one end of the auxiliary winding, and used to generate a main control power supply signal according to the auxiliary coupling signal;

[0010] A main control circuit, connected to the high-voltage start-up circuit and the power supply circuit, configured to start working under the action of the high-voltage start-up signal, and then work normally under the action of the main control power supply signal, and alternately output a first control signal and a second control signal in a working state;

[0011] a gallium nitride driving circuit, connected to the main control circuit and the gallium nitride switch tube, and configured to generate the first driving signal under the action of the first control signal and to generate the second driving signal under the action of the second control signal;

[0012] a valley conduction circuit, connected to one end of the auxiliary winding and the main control circuit, and configured to generate a valley conduction signal according to the auxiliary coupling signal, so that the main control circuit outputs the first control signal in a fixed delay manner, and further enables the gallium nitride switch tube to conduct at the valley bottom through the first drive signal, thereby achieving a quasi-resonant state;

[0013] An output rectification and filtering circuit, connected to the secondary winding, for rectifying and filtering the secondary coupled signal to obtain an output signal;

[0014] A fast charging protocol detection circuit, connected to the output rectifier and filter circuit, for supporting a variety of fast charging protocols, and adjusting the output signal according to various fast charging protocols to obtain a corresponding fast charging signal and an output feedback signal;

[0015] A feedback circuit is connected to the output rectification and filtering circuit, the fast charging protocol detection circuit, the main control circuit and the other end of the auxiliary winding, and is used to generate a feedback adjustment signal according to the output signal and the output feedback signal to control the stability of the output signal through the main control circuit.

[0016] The beneficial effects of the present invention are: a gallium nitride switching power supply based on multiple fast charging protocols of the present invention adopts a gallium nitride switching tube, which has the characteristics of high critical breakdown voltage and fast electron mobility; at the same time, under the drive of the gallium nitride driving circuit, the gallium nitride switching tube can be slowly opened and quickly closed, thereby eliminating the spikes of the secondary winding synchronous rectification; and under the action of the valley bottom conduction circuit, the gallium nitride switching tube can be turned on near the valley bottom, which can greatly improve the conversion efficiency of the system, reduce switching losses, and allow the entire circuit to reach a quasi-resonant state; in addition, the present invention also designs a fast charging protocol detection circuit that supports multiple fast charging protocols, which can realize fast charging of multiple protocols, thereby solving the compatibility and efficiency problems of different devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a structural block diagram of a gallium nitride switching power supply based on multiple fast charging protocols of the present invention;

[0018] Figure 2 This is a partial circuit schematic diagram of a gallium nitride switching power supply based on multiple fast charging protocols of the present invention;

[0019] Figure 3 This is another partial circuit schematic diagram of a gallium nitride switching power supply based on multiple fast charging protocols of the present invention. DETAILED DESCRIPTION

[0020] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0021] like Figure 1 As shown, a GaN switching power supply based on multiple fast charging protocols includes:

[0022] An input rectifying and filtering circuit 1 is connected between the AC signal and a common ground GND, and is used to rectify and filter the AC signal to obtain a DC signal;

[0023] Transformer T1, comprising a primary winding, an auxiliary winding and a secondary winding, one end of the primary winding being connected to the input rectifier filter circuit 1;

[0024] A gallium nitride switch tube Q2, the gate of which is alternately connected to the first drive signal and the second drive signal, the drain of which is connected to the other end of the primary winding, and the source of which is connected to the signal ground SGND, and is used for slowly turning on under the action of the first drive signal and quickly turning off under the action of the second drive signal, so that the DC signal is converted into a square wave signal in the primary winding, and then the square wave signal in the primary winding is coupled to the auxiliary winding and the secondary winding, so as to generate corresponding auxiliary coupling signals and secondary coupling signals in the auxiliary winding and the secondary winding respectively;

[0025] A high-voltage starting circuit 2, connected to the input rectifying and filtering circuit 1, for generating a high-voltage starting signal according to the DC signal;

[0026] A power supply circuit 3, connected to one end of the auxiliary winding, and used to generate a main control power supply signal according to the auxiliary coupling signal;

[0027] A main control circuit 4, connected to the high-voltage start-up circuit 2 and the power supply circuit 3, is used to start working under the action of the high-voltage start-up signal, and then work normally under the action of the main control power supply signal, and alternately outputs a first control signal and a second control signal in the working state;

[0028] a gallium nitride driving circuit 5, connected to the main control circuit 4 and the gallium nitride switch tube Q2, and configured to generate the first driving signal under the action of the first control signal and to generate the second driving signal under the action of the second control signal;

[0029] A valley conduction circuit 6 is connected to one end of the auxiliary winding and the main control circuit 4, and is used to generate a valley conduction signal according to the auxiliary coupling signal, so that the main control circuit 4 outputs the first control signal in a fixed delay manner, and then the gallium nitride switch tube Q2 is turned on at the valley bottom through the first driving signal, thereby achieving a quasi-resonant state;

[0030] An output rectifying and filtering circuit 7, connected to the secondary winding, for rectifying and filtering the secondary coupled signal to obtain an output signal;

[0031] The fast charging protocol detection circuit 8 is connected to the output rectification and filtering circuit 7, and is used to support multiple fast charging protocols, and adjust the output signal according to various fast charging protocols to obtain corresponding fast charging signals and output feedback signals;

[0032] The feedback circuit 9 is connected to the output rectification and filtering circuit 7, the fast charging protocol detection circuit 8, the main control circuit 4 and the other end of the auxiliary winding, and is used to generate a feedback adjustment signal according to the output signal and the output feedback signal to control the stability of the output signal through the main control circuit 4.

[0033] The present invention discloses a gallium nitride switching power supply based on multiple fast charging protocols, which adopts a gallium nitride switch tube Q2. The gallium nitride switch tube Q2 has the characteristics of high critical breakdown voltage and fast electron mobility. At the same time, under the drive of the gallium nitride driving circuit 5, the gallium nitride switch tube Q2 can be slowly opened and quickly closed, thereby eliminating the peak of the secondary winding synchronous rectification. Under the action of the valley bottom conduction circuit 6, the gallium nitride switch tube Q2 can be turned on near the valley bottom. This method can greatly improve the conversion efficiency of the system, reduce switching losses, and allow the entire circuit to reach a quasi-resonant state. In addition, the present invention also designs a fast charging protocol detection circuit 8 that supports multiple fast charging protocols, which can realize fast charging of multiple protocols, thereby solving the compatibility and efficiency problems of different devices.

[0034] In this embodiment, if Figure 2 As shown, the input rectification and filtering circuit 1 includes:

[0035] Common mode inductor U1, a group of ports are connected to the AC power;

[0036] A capacitor C1 connected to another group of ports of the common mode inductor U1;

[0037] The rectifier bridge U2 has two input terminals connected to the capacitor C1;

[0038] The electrolytic capacitor U3 is connected to the two output terminals of the rectifier bridge U2 and to the common ground GND;

[0039] An inductor L1, one end of which is connected to an output end of the rectifier bridge U2;

[0040] An electrolytic capacitor U4, one end of which is connected to the other end of the inductor L1, and the other end of which is connected to the common ground GND;

[0041] Capacitor C2, connected in parallel to the electrolytic capacitor U4;

[0042] Capacitor C3, connected in parallel to the electrolytic capacitor U4;

[0043] The other end of the inductor L1 outputs the DC signal.

[0044] Specifically, in the input rectifier filter circuit 1, the AC signal is connected between the live wire L and the neutral wire N, and the AC signal is specifically 220V AC mains power; a fuse F1 is also connected in series between the live wire L and the common mode inductor U1. The EMI filter circuit composed of the common mode inductor U1 and the capacitor C1 filters out high-frequency noise in the power grid to prevent interference with the system, and converts the input 220V AC power into DC; the electrolytic capacitor U3, the inductor L1, the electrolytic capacitor U4, the capacitor C2 and the capacitor C3 form a filter circuit, which changes the half-wave passing through the rectifier bridge U2 into a relatively stable DC; wherein, the electrolytic capacitor U3, the inductor L1 and the electrolytic capacitor U4 form a π-type filter circuit, and its filtering effect is higher than that of a single capacitor; the capacitor C2 and the capacitor C3 use electrolytic capacitors to filter out some high-frequency interference in the signal.

[0045] In this embodiment, if Figure 2 As shown, the main control circuit 4 includes a control chip U12, and the control chip U12 is provided with a DEM pin, an FB pin, an HV pin, a VDDH pin, a VDDL pin, a CS pin and a GATE pin.

[0046] In this embodiment, if Figure 2 As shown, the high voltage starting circuit 2 includes:

[0047] A resistor R13, one end of which is connected to the input rectifier filter circuit 1 to access the DC signal, and the other end of which is connected to the HV pin of the control chip U12;

[0048] The power supply circuit 3 comprises:

[0049] A diode D9, the anode of which is connected to one end of the auxiliary winding;

[0050] A resistor R22, one end of which is connected to the cathode of the diode D9, and the other end of which is connected to the VDDH pin of the control chip U12;

[0051] The capacitor C20 has one end connected to the other end of the resistor R22 and the other end connected to the signal ground SGND.

[0052] Specifically, in the initial stage of power on, the DC signal passing through the input rectifier filter circuit 1 is cut off when it reaches the drain of the GaN switch tube Q2 through the primary winding. However, due to the existence of the resistor R13 in the high-voltage startup circuit 2, the DC signal reaches the drain of the GaN switch tube Q2 and also reaches the HV pin of the control chip U12 through the resistor R13. The first control signal is output to the GATE pin of the control chip U12 through the high-voltage startup, and the first drive signal is generated through the GaN drive circuit 5 to drive the GaN switch tube Q2 to turn on. Therefore, the GaN switch tube Q2 forms a square wave signal in the primary winding, and through this square wave signal, the transformer is coupled, so that the primary winding of the transformer is coupled to the auxiliary winding and the secondary winding; therefore, connecting the auxiliary winding power supply circuit can supply power to the control chip U12, allowing the control chip U12 to work normally and stably, and then the control chip U12 works normally.

[0053] In addition, in the power supply circuit 3, the diode D9 and the resistor R22 are connected in series to eliminate the negative voltage in the auxiliary winding and absorb the peak voltage, and the capacitor C20 is used to filter out the high-frequency interference in the auxiliary winding and store energy.

[0054] In this embodiment, if Figure 2 As shown, the gallium nitride driving circuit 5 includes:

[0055] A resistor R16, one end of which is connected to the GATE pin of the control chip U12;

[0056] A diode D8, a cathode of which is connected to the other end of the resistor R16;

[0057] A resistor R17, one end of which is connected to the GATE pin of the control chip U12, and the other end of which is connected to the anode of the diode D8;

[0058] A capacitor C16, one end of which is connected to the anode of the diode D8, and the other end of which is connected to the gate of the gallium nitride switch tube Q2;

[0059] A resistor R15 connected in parallel to the capacitor C16;

[0060] A voltage regulator tube ZD1, a negative electrode of which is connected to the other end of the capacitor C16;

[0061] A voltage regulator tube ZD2, with a positive electrode connected to the positive electrode of the voltage regulator tube ZD1 and a negative electrode connected to the signal ground SGND;

[0062] Capacitor C18, one end of which is connected to the negative electrode of the voltage regulator ZD2, and the other end of which is connected to the VDDL pin of the control chip U12;

[0063] The resistor R19 has one end connected to the cathode of the voltage regulator tube ZD1 and the other end connected to the cathode of the voltage regulator tube ZD2.

[0064] Specifically, in the gallium nitride drive circuit, E-mode GaN drive is adopted, which has low standby power consumption and high efficiency; the resistor R16 and the diode D8 are connected in series and the two are connected in parallel with the resistor R17, so that the gallium nitride switch tube Q2 can be opened slowly and closed quickly, eliminating the spike of the secondary winding synchronous rectification, and the capacitor C16 and the resistor R15 are connected in parallel to the Zener tube ZD1 and the Zener tube ZD2 to allow the entire drive circuit to generate a stable drive voltage and a negative voltage at the same time, which is more conducive to the shutdown of the gallium nitride switch tube Q2.

[0065] In this embodiment, if Figure 2 As shown, the valley conduction circuit 6 includes:

[0066] A resistor R25, one end of which is connected to one end of the auxiliary winding, and the other end of which is connected to the DEM pin of the control chip U12;

[0067] A resistor R26, one end of which is connected to the other end of the resistor R25, and the other end of which is connected to the signal ground SGND;

[0068] The capacitor C23 is connected in parallel to the resistor R26.

[0069] Specifically, in the valley conduction circuit 6, the auxiliary coupling signal in the auxiliary winding is divided by resistors R25 and R26, and the DEM pin of the control chip U12 samples the divided signal and turns on the gallium nitride switch Q2 near the valley with a fixed delay. This method can greatly improve the conversion efficiency of the system, reduce switching losses, and allow the entire circuit to reach a quasi-resonant state.

[0070] In this embodiment, if Figure 2 As shown, the output rectification and filtering circuit 7 includes:

[0071] The synchronous rectifier chip U7 has an input end connected to one end of the secondary winding.

[0072] An electrolytic capacitor C4, one end of which is connected to the output end of the synchronous rectifier chip U7, and the other end of which is connected to the other end of the secondary winding and connected to the analog ground AGND;

[0073] Capacitor C5, connected in parallel to the electrolytic capacitor C4;

[0074] The common mode inductor U5 has one group of ports connected to the capacitor C5 and another group of ports outputting the output signal and connected to the analog ground AGND.

[0075] Specifically, in the output rectifier filter circuit 7, the negative half voltage of the system output is eliminated by the synchronous rectifier chip U7, and then the filter circuit composed of the electrolytic capacitor C4, the capacitor C5 and the common mode inductor U5 is used to eliminate the high-frequency interference; the capacitor C5 is a solid capacitor with low ESR and high rated ripple current.

[0076] In this embodiment, if Figure 3 As shown, the fast charging protocol detection circuit 8 includes an interface chip USB1 and a fast charging protocol chip U6 connected to each other; wherein the fast charging protocol chip U6 supports multiple fast charging protocols, the VI N pin of the fast charging protocol chip U6 is connected to the output rectifier filter circuit 7 to access the output signal, the OPTO / FB pin of the fast charging protocol chip U6 outputs the output feedback signal, and the interface chip USB1 outputs the fast charging signal;

[0077] The fast charge protocol detection circuit 8 also includes:

[0078] A capacitor C13 and a resistor R10 connected in series between the VFB pin and the OPTO / FB pin of the fast charging protocol chip U6;

[0079] A capacitor C15 and a resistor R12 connected in series between the I FB pin and the OPTO / FB pin of the fast charging protocol chip U6;

[0080] A diode D2 and a capacitor C6 connected to the CC1 pin of the fast charging protocol chip U6; wherein the cathode of the diode D2 and one end of the capacitor C6 are connected to the CC1 pin of the fast charging protocol chip U6, and the anode of the diode D2 and the other end of the capacitor C6 are connected to the power ground PGND and the analog ground AGND respectively;

[0081] A diode D3 and a capacitor C10 connected to the CC2 pin of the fast charging protocol chip U6; wherein the cathode of the diode D3 and one end of the capacitor C10 are connected to the CC2 pin of the fast charging protocol chip U6, and the anode of the diode D3 and the other end of the capacitor C10 are connected to the power ground PGND and the analog ground AGND respectively;

[0082] A diode D4 connected between the DM pin of the fast charging protocol chip U6 and the power ground PGND;

[0083] A diode D7 connected between the DP pin of the fast charging protocol chip U6 and the power ground PGND;

[0084] A resistor R5 connected between the PSET pin of the fast charging protocol chip U6 and the analog ground AGND;

[0085] Among them, the tolerance of the signal line connected to the CC1 pin of the fast charging protocol chip U6 and composed of the diode D2 and the capacitor C6 is equal to the tolerance of the signal line connected to the CC2 pin of the fast charging protocol chip U6 and composed of the diode D3 and the capacitor C10; the tolerance of the signal line connected between the DM pin of the fast charging protocol chip U6 and the power ground PGND and composed of the diode D4 is equal to the tolerance of the signal line connected between the DP pin of the fast charging protocol chip U6 and the power ground PGND and composed of the diode D7.

[0086] Specifically, in the fast charging protocol detection circuit 8, the model of the fast charging protocol chip U6 is SW2325; in addition, Figure 3 Q1 in the control protocol is an NMOS tube, and its function is: if the voltage in the output protocol is consistent with the voltage output by the power supply, the NMOS tube is turned on, otherwise the NMOS tube is turned off. CV (constant voltage) loop compensation is achieved through the series circuit of resistor R10 and capacitor C13 between the VFB pin and the OPTO / FB pin, while CC (constant current) loop compensation is achieved through the series circuit of resistor R12 and capacitor C15 between the I FB pin and the OPTO / FB pin; at the same time, the resistor R5 is set to 36K, with a maximum output power of 100W; CC1 pin and CC2 pin, DP pin and DM pin all use differential routing to ensure signal stability. Through settings, the system can support multiple fast charging protocols such as QC, SCP, AFC, PD, FCP, etc.

[0087] In this embodiment, if Figure 2 As shown, the feedback circuit 9 includes:

[0088] A resistor R20, one end of which is connected to the output rectifier filter circuit 7 to access the output signal;

[0089] A resistor R24, one end of which is connected to the other end of the resistor R20, and the other end of which is connected to the fast charge protocol detection circuit 8 to access the output feedback signal;

[0090] Optocoupler U13, the positive electrode of the light-emitting end is connected between the resistor R20 and the resistor R24, the negative electrode of the light-emitting end is connected to the other end of the resistor R24, the emitter of the light-receiving end is connected to the other end of the auxiliary winding and connected to the signal ground SGND, and the collector of the light-receiving end is connected to the FB pin of the control chip U12;

[0091] The capacitor C24 is connected between the light receiving end collector and the light receiving end emitter of the optical coupler U13.

[0092] Specifically, the main function of the feedback circuit 9 is to maintain the stability of the output signal, adjust the change of the output signal through negative feedback, and quickly adjust the working state of the internal circuit to offset this effect. In layman's terms, if the voltage of the output signal is too high, the feedback circuit 9 will feedback the output signal voltage to the control chip U12, and then the control chip U12 can reduce its own operating frequency to reduce the voltage of the output signal. Similarly, if the voltage of the output signal is too low, the operating frequency will be increased.

[0093] In this embodiment, if Figure 1 As shown, the gallium nitride switching power supply based on multiple fast charging protocols of the present invention also includes:

[0094] An RCD peak absorption circuit 10 is connected to both ends of the primary coil and is used to absorb the peak voltage formed in the primary coil due to leakage inductance;

[0095] like Figure 2 As shown, the RCD peak absorption circuit 10 includes:

[0096] A capacitor C12, one end of which is connected to one end of the primary coil;

[0097] A resistor R9, one end of which is connected to one end of the primary coil;

[0098] A resistor R8, one end of which is connected to one end of the primary coil;

[0099] A heat dissipation resistor U10, one end of which is connected to the other end of the capacitor C12, the other end of the resistor R9 and the other end of the resistor R8;

[0100] A heat dissipation resistor U11, one end of which is connected to the other end of the capacitor C12, the other end of the resistor R9 and the other end of the resistor R8;

[0101] The diode D6 has a cathode connected to the other end of the heat dissipation resistor U10 and the other end of the heat dissipation resistor U11 , and a cathode connected to the other end of the primary coil.

[0102] Specifically, the RCD peak absorption circuit is used to absorb the peak generated by the leakage inductance of the transformer to prevent the peak high voltage from affecting the gallium nitride switch tube Q2.

[0103] In this embodiment, if Figure 1 As shown, the gallium nitride switching power supply based on multiple fast charging protocols of the present invention also includes:

[0104] A CS current sampling circuit 11 is connected between the common ground GND and the signal ground SGND and is connected to the main control circuit 4, and is used for collecting system current and transmitting the collected system current to the main control circuit 4;

[0105] like Figure 2 As shown, the CS current sampling circuit 11 includes:

[0106] A resistor R2, one end of which is connected to the common ground GND, and the other end of which is connected to the signal ground SGND;

[0107] A resistor R3, one end of which is connected to the common ground GND, and the other end of which is connected to the signal ground SGND;

[0108] A resistor R4, one end of which is connected to the common ground GND, and the other end of which is connected to the signal ground SGND;

[0109] A resistor R23, one end of which is connected to the common ground GND, and the other end of which is connected to the CS pin of the control chip U12;

[0110] The capacitor C22 has one end connected to the signal ground SGND, and the other end connected to the CS pin of the control chip U12.

[0111] Specifically, in the CS current sampling circuit 11, the operating frequency of the entire system can be set by adjusting the value of the resistor R23, and the operating current of the system can also be determined by sampling the voltage across the resistor R23. Resistors R2, R3, and R4 are sampling resistors. The signal flowing through the GaN switch tube Q2 reaches the signal ground SGND and then flows to resistors R2, R3, and R4, and finally enters the common ground GND; resistors R2, R3, and R4 are used to detect the current size of the system so that the control chip U12 controls the operation of the GaN switch tube Q2. At the same time, if the current is overcurrent, the resistor R23 and the capacitor C22 trigger the control chip U12 to perform overcurrent protection.

[0112] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A gallium nitride switching power supply based on multiple fast charging protocols, characterized in that: include: An input rectifying and filtering circuit is connected between the AC signal and a common ground, and is used to rectify and filter the AC signal to obtain a DC signal; A transformer, comprising a primary winding, an auxiliary winding and a secondary winding, wherein one end of the primary winding is connected to the input rectifying and filtering circuit; A gallium nitride switch tube, the gate of which is alternately connected to the first drive signal and the second drive signal, the drain of which is connected to the other end of the primary winding, and the source of which is connected to the signal ground, and is used to slowly turn on under the action of the first drive signal and quickly turn off under the action of the second drive signal, so that the DC signal is converted into a square wave signal in the primary winding, and then the square wave signal in the primary winding is coupled to the auxiliary winding and the secondary winding, so as to generate corresponding auxiliary coupling signals and secondary coupling signals in the auxiliary winding and the secondary winding respectively; A high-voltage starting circuit, connected to the input rectifying and filtering circuit, and used for generating a high-voltage starting signal according to the DC signal; a power supply circuit, connected to one end of the auxiliary winding, and used to generate a main control power supply signal according to the auxiliary coupling signal; A main control circuit, connected to the high-voltage start-up circuit and the power supply circuit, configured to start working under the action of the high-voltage start-up signal, and then work normally under the action of the main control power supply signal, and alternately output a first control signal and a second control signal in a working state; a gallium nitride driving circuit, connected to the main control circuit and the gallium nitride switch tube, and configured to generate the first driving signal under the action of the first control signal and to generate the second driving signal under the action of the second control signal; a valley conduction circuit, connected to one end of the auxiliary winding and the main control circuit, and configured to generate a valley conduction signal according to the auxiliary coupling signal, so that the main control circuit outputs the first control signal in a fixed delay manner, and further enables the gallium nitride switch tube to conduct at the valley bottom through the first drive signal, thereby achieving a quasi-resonant state; An output rectification and filtering circuit, connected to the secondary winding, for rectifying and filtering the secondary coupled signal to obtain an output signal; A fast charging protocol detection circuit, connected to the output rectifier and filter circuit, for supporting a variety of fast charging protocols, and adjusting the output signal according to various fast charging protocols to obtain a corresponding fast charging signal and an output feedback signal; A feedback circuit is connected to the output rectification and filtering circuit, the fast charging protocol detection circuit, the main control circuit and the other end of the auxiliary winding, and is used to generate a feedback adjustment signal according to the output signal and the output feedback signal to control the stability of the output signal through the main control circuit.

2. The gallium nitride switching power supply based on multiple fast charging protocols according to claim 1, characterized in that: The main control circuit includes a control chip U12, and the control chip U12 is provided with a GATE pin and a VDDL pin; the gallium nitride driving circuit includes: A resistor R16, one end of which is connected to the GATE pin of the control chip U12; A diode D8, a cathode of which is connected to the other end of the resistor R16; A resistor R17, one end of which is connected to the GATE pin of the control chip U12, and the other end of which is connected to the anode of the diode D8; A capacitor C16, one end of which is connected to the anode of the diode D8, and the other end of which is connected to the gate of the gallium nitride switch tube; A resistor R15 connected in parallel to the capacitor C16; A voltage regulator tube ZD1, a negative electrode of which is connected to the other end of the capacitor C16; A voltage regulator tube ZD2, the positive electrode of which is connected to the positive electrode of the voltage regulator tube ZD1, and the negative electrode of which is connected to the signal ground; Capacitor C18, one end of which is connected to the negative electrode of the voltage regulator ZD2, and the other end of which is connected to the VDDL pin of the control chip U12; The resistor R19 has one end connected to the cathode of the voltage regulator tube ZD1 and the other end connected to the cathode of the voltage regulator tube ZD2.

3. The gallium nitride switching power supply based on multiple fast charging protocols according to claim 1, characterized in that: The main control circuit includes a control chip U12, and a DEM pin is provided in the control chip U12; the valley conduction circuit includes: A resistor R25, one end of which is connected to one end of the auxiliary winding, and the other end of which is connected to the DEM pin of the control chip U12; A resistor R26, one end of which is connected to the other end of the resistor R25, and the other end of which is connected to the signal ground; The capacitor C23 is connected in parallel to the resistor R26.

4. The gallium nitride switching power supply based on multiple fast charging protocols according to claim 1, characterized in that: The main control circuit includes a control chip U12, and the control chip U12 is provided with a HV pin and a VDDH pin; the high-voltage startup circuit includes: A resistor R13, one end of which is connected to the input rectifier filter circuit to access the DC signal, and the other end of which is connected to the HV pin of the control chip U12; The power supply circuit comprises: A diode D9, the anode of which is connected to one end of the auxiliary winding; A resistor R22, one end of which is connected to the cathode of the diode D9, and the other end of which is connected to the VDDH pin of the control chip U12; The capacitor C20 has one end connected to the other end of the resistor R22 and the other end connected to the signal ground.

5. The gallium nitride switching power supply based on multiple fast charging protocols according to claim 1, characterized in that: The fast charging protocol detection circuit includes an interface chip USB1 and a fast charging protocol chip U6 connected to each other; wherein the fast charging protocol chip U6 supports multiple fast charging protocols, the VIN pin of the fast charging protocol chip U6 is connected to the output rectifier filter circuit to access the output signal, the OPTO / FB pin of the fast charging protocol chip U6 outputs the output feedback signal, and the interface chip USB1 outputs the fast charging signal; The fast charge protocol detection circuit also includes: A capacitor C13 and a resistor R10 connected in series between the VFB pin and the OPTO / FB pin of the fast charging protocol chip U6; A capacitor C15 and a resistor R12 connected in series between the IFB pin and the OPTO / FB pin of the fast charging protocol chip U6; A diode D2 and a capacitor C6 connected to the CC1 pin of the fast charging protocol chip U6; wherein the cathode of the diode D2 and one end of the capacitor C6 are connected to the CC1 pin of the fast charging protocol chip U6, and the anode of the diode D2 and the other end of the capacitor C6 are connected to the power ground and the analog ground respectively; A diode D3 and a capacitor C10 connected to the CC2 pin of the fast charging protocol chip U6; wherein the cathode of the diode D3 and one end of the capacitor C10 are connected to the CC2 pin of the fast charging protocol chip U6, and the anode of the diode D3 and the other end of the capacitor C10 are connected to the power ground and the analog ground respectively; A diode D4 connected between the DM pin of the fast charging protocol chip U6 and the power ground; A diode D7 connected between the DP pin of the fast charging protocol chip U6 and the power ground; A resistor R5 connected between the PSET pin of the fast charging protocol chip U6 and the analog ground; Among them, the tolerance of the signal line connected to the CC1 pin of the fast charging protocol chip U6 and composed of the diode D2 and the capacitor C6 is equal to the tolerance of the signal line connected to the CC2 pin of the fast charging protocol chip U6 and composed of the diode D3 and the capacitor C10; the tolerance of the signal line connected between the DM pin of the fast charging protocol chip U6 and the power ground and composed of the diode D4 is equal to the tolerance of the signal line connected between the DP pin of the fast charging protocol chip U6 and the power ground and composed of the diode D7.

6. The gallium nitride switching power supply based on multiple fast charging protocols according to claim 1, characterized in that: The main control circuit includes a control chip U12, and the control chip U12 is provided with an FB pin; the feedback circuit includes: A resistor R20, one end of which is connected to the output rectifier and filter circuit to access the output signal; A resistor R24, one end of which is connected to the other end of the resistor R20, and the other end of which is connected to the fast charge protocol detection circuit to access the output feedback signal; Optocoupler U13, the positive electrode of the light-emitting end is connected between the resistor R20 and the resistor R24, the negative electrode of the light-emitting end is connected to the other end of the resistor R24, the emitter of the light-receiving end is connected to the other end of the auxiliary winding and connected to the signal ground, and the collector of the light-receiving end is connected to the FB pin of the control chip U12; The capacitor C24 is connected between the light receiving end collector and the light receiving end emitter of the optical coupler U13.

7. The gallium nitride switching power supply based on multiple fast charging protocols according to claim 1, characterized in that: The input rectification and filtering circuit comprises: Common mode inductor U1, a group of ports are connected to the AC power; A capacitor C1 connected to another group of ports of the common mode inductor U1; The rectifier bridge U2 has two input terminals connected to the capacitor C1; The electrolytic capacitor U3 is connected to the two output terminals of the rectifier bridge U2 and to the common ground; An inductor L1, one end of which is connected to an output end of the rectifier bridge U2; An electrolytic capacitor U4, one end of which is connected to the other end of the inductor L1, and the other end of which is connected to the common ground; Capacitor C2, connected in parallel to the electrolytic capacitor U4; Capacitor C3, connected in parallel to the electrolytic capacitor U4; The other end of the inductor L1 outputs the DC signal.

8. The gallium nitride switching power supply based on multiple fast charging protocols according to claim 1, characterized in that: The output rectification and filtering circuit comprises: The synchronous rectifier chip U7 has an input end connected to one end of the secondary winding. An electrolytic capacitor C4, one end of which is connected to the output end of the synchronous rectifier chip U7, and the other end of which is connected to the other end of the secondary winding and to the analog ground; Capacitor C5, connected in parallel to the electrolytic capacitor C4; The common mode inductor U5 has one group of ports connected to the capacitor C5 and another group of ports outputting the output signal and connecting to the analog ground.

9. The gallium nitride switching power supply based on multiple fast charging protocols according to claim 1, characterized in that: Also includes: An RCD peak absorption circuit is connected to both ends of the primary coil and is used to absorb the peak voltage formed in the primary coil due to leakage inductance; The RCD peak absorption circuit comprises: A capacitor C12, one end of which is connected to one end of the primary coil; A resistor R9, one end of which is connected to one end of the primary coil; A resistor R8, one end of which is connected to one end of the primary coil; A heat dissipation resistor U10, one end of which is connected to the other end of the capacitor C12, the other end of the resistor R9 and the other end of the resistor R8; A heat dissipation resistor U11, one end of which is connected to the other end of the capacitor C12, the other end of the resistor R9 and the other end of the resistor R8; The diode D6 has a cathode connected to the other end of the heat dissipation resistor U10 and the other end of the heat dissipation resistor U11 , and a cathode connected to the other end of the primary coil.

10. The gallium nitride switching power supply based on multiple fast charging protocols according to claim 1, characterized in that: Also includes: A CS current sampling circuit is connected between the common ground and the signal ground and is connected to the main control circuit, and is used to collect system current and transmit the collected system current to the main control circuit; The main control circuit includes a control chip U12, and a CS pin is provided in the control chip U12; The CS current sampling circuit comprises: A resistor R2, one end of which is connected to the common ground, and the other end of which is connected to the signal ground; A resistor R3, one end of which is connected to the common ground, and the other end of which is connected to the signal ground; A resistor R4, one end of which is connected to the common ground, and the other end of which is connected to the signal ground; A resistor R23, one end of which is connected to the common ground, and the other end of which is connected to the CS pin of the control chip U12; Capacitor C22 has one end connected to the signal ground, and the other end connected to the CS pin of the control chip U12.

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