A Gallium Nitride switching power supply based on multiple fast charging protocols

Abstract

The present invention relates to a gallium nitride switching power supply based on multiple fast charging protocols, comprising: a transformer; a gallium nitride switching tube, 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; a main control circuit; a gallium nitride driving circuit, connected to the main control circuit and the gallium nitride switching tube; a valley conduction circuit, connected to one end of the auxiliary winding and the main control circuit; an output rectifying and filtering circuit; and a fast charging protocol detection circuit, connected to the output rectifying and filtering circuit. In the present invention, a gallium nitride switching tube is adopted, which has a high critical breakdown voltage and fast electron mobility; the gallium nitride driving circuit can realize slow turn-on and fast turn-off of the gallium nitride switching tube, thereby eliminating the spikes of the synchronous rectification of the secondary winding; the valley conduction circuit can make the gallium nitride switching tube conduct near the valley, and this way can greatly improve the conversion efficiency of the system, reduce the switching loss, and make the whole circuit reach a quasi-resonant state; in addition, the fast charging protocol detection circuit can realize fast charging of multiple protocols.

Description

Technical Field

[0001] The present invention relates to the field of switching power supplies, and particularly 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 adjusts the output voltage and current through the rapid switching of switching elements to achieve power conversion. Currently, most switching power supplies on the market are silicon-based switching power supplies, and silicon-based switching power supplies have the disadvantages of high losses and low performance under high-temperature conditions. In addition, most switching power supplies on the market today only support a single fast charging protocol, and some switching power supplies that support multiple fast charging protocols have compatibility and efficiency problems 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 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 includes:

[0005] An input rectifier filter circuit, connected between an AC signal and a common ground, for rectifying and filtering the AC signal to obtain a DC signal;

[0006] A transformer, including a primary winding, an auxiliary winding, and a secondary winding, one end of the primary winding is connected to the input rectifier filter circuit;

[0007] A gallium nitride switching transistor, whose gate is alternately connected to a first driving signal and a second driving signal, the drain is connected to the other end of the primary winding, and the source is connected to the signal ground, for slowly conducting under the action of the first driving signal and quickly turning off under the action of the second driving signal, so that the DC signal is transformed 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, thereby generating corresponding auxiliary coupling signals and secondary coupling signals in the auxiliary winding and the secondary winding respectively;

[0008] A high-voltage startup circuit, connected to the input rectifier filter circuit, for generating a high-voltage startup signal according to the DC signal;

[0009] A power supply circuit, connected to one end of the auxiliary winding, for generating a main control power signal according to the auxiliary coupling signal;

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

[0011] The gallium nitride drive circuit, connected to the main control circuit and the gallium nitride switch tube, is used to generate the first drive signal under the action of the first control signal and generate the second drive signal under the action of the second control signal;

[0012] The valley conduction circuit, connected to one end of the auxiliary winding and the main control circuit, is used 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 then makes the gallium nitride switch tube conduct at the valley through the first drive signal, so as to reach the quasi-resonant state;

[0013] The output rectification and filtering circuit, connected to the secondary winding, is used to rectify and filter the secondary coupling signal to obtain an output signal;

[0014] The fast charging protocol detection circuit, connected to the output rectification and filtering circuit, is used to support multiple fast charging protocols and correspondingly adjust the output signal according to various fast charging protocols to obtain corresponding fast charging signals and output feedback signals;

[0015] The feedback circuit, 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, 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 as follows: A gallium nitride switching power supply based on multiple fast charging protocols in the present invention uses a gallium nitride switch tube, which has the characteristics of high critical breakdown voltage and fast electron mobility; at the same time, slow opening and fast closing of the gallium nitride switch tube can be realized under the drive of the gallium nitride drive circuit, so as to eliminate the spikes of synchronous rectification of the secondary winding; and under the action of the valley conduction circuit, the gallium nitride switch tube can be made to conduct near the valley, and such a method can greatly improve the conversion efficiency of the system, reduce the switching loss, and make the entire circuit 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, thus solving the compatibility problem and efficiency problem for different devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural block diagram of a gallium nitride switching power supply based on multiple fast charging protocols in 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 according to 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 according to the present invention. Specific embodiments

[0020] The principles and features of the present invention will be described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

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

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

[0023] A transformer T1, including 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 switching transistor Q2, whose gate is alternately connected to a first drive signal and a second drive signal, whose drain is connected to the other end of the primary winding, and whose source is connected to a signal ground SGND, for slowly conducting 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, thereby generating corresponding auxiliary coupling signals and secondary coupling signals in the auxiliary winding and the secondary winding respectively;

[0025] A high-voltage start-up circuit 2, connected to the input rectifier filter circuit 1, for generating a high-voltage start-up signal according to the DC signal;

[0026] A power supply circuit 3, connected to one end of the auxiliary winding, for generating a main control power 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, for starting to work under the action of the high-voltage start-up signal, and then working normally under the action of the main control power signal, and alternately outputting a first control signal and a second control signal in the working state;

[0028] A gallium nitride drive circuit 5, connected to the main control circuit 4 and the gallium nitride switching transistor Q2, for generating the first drive signal under the action of the first control signal and generating the second drive signal under the action of the second control signal;

[0029] The valley conduction circuit 6, connected to one end of the auxiliary winding and the main control circuit 4, is configured 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 Q2 is turned on at the valley through the first drive signal, thereby achieving a quasi-resonant state;

[0030] The output rectification and filtering circuit 7, connected to the secondary winding, is configured to rectify and filter the secondary coupling signal to obtain an output signal;

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

[0032] The feedback circuit 9, 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, is configured 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 gallium nitride switch power supply based on multiple fast charging protocols in the present invention uses a gallium nitride switch Q2, which has the characteristics of high critical breakdown voltage and fast electron mobility; at the same time, the gallium nitride switch Q2 can be slowly turned on and quickly turned off under the drive of the gallium nitride drive circuit 5, thereby eliminating the spikes of the secondary winding synchronous rectification; and under the action of the valley conduction circuit 6, the gallium nitride switch Q2 can be turned on near the valley, and such a method can greatly improve the conversion efficiency of the system, reduce the switching loss, and make the whole circuit 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 achieve fast charging of multiple protocols, thereby solving the compatibility problem and efficiency problem for different devices.

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

[0035] The common-mode inductor U1, with a group of ports connected to the alternating current;

[0036] The capacitor C1, connected to the other group of ports of the common-mode inductor U1;

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

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

[0039] The inductor L1 has one end connected to an output terminal of the rectifier bridge U2;

[0040] The electrolytic capacitor U4 has one end connected to the other end of the inductor L1 and the other end connected to the common ground GND;

[0041] The capacitor C2 is connected in parallel with the electrolytic capacitor U4;

[0042] The capacitor C3 is connected in parallel with the electrolytic capacitor U4;

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

[0044] Specifically, in the input rectifier and 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; 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 to the system and converts the input 220V AC into DC; the electrolytic capacitor U3, the inductor L1, the electrolytic capacitor U4, the capacitor C2 and the capacitor C3 form a filter circuit to convert the half-wave after 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 filter; the capacitor C2 and the capacitor C3 use electrolytic capacitors to filter out some high-frequency interference in the signal.

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

[0046] In this embodiment, as Figure 2 shown, the high-voltage startup circuit 2 includes:

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

[0048] The power supply circuit 3 includes:

[0049] The diode D9 has its positive electrode connected to one end of the auxiliary winding;

[0050] The resistor R22 has one end connected to the negative electrode of the diode D9 and the other end 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 when the power supply is turned on, the DC signal passing through the input rectifier and filter circuit 1 is cut off when it reaches the drain of the gallium nitride switching transistor Q2 through the primary winding. However, due to the presence of the resistor R13 in the high-voltage startup circuit 2, when the DC signal reaches the drain of the gallium nitride switching transistor Q2, it also reaches the HV pin of the control chip U12 through the resistor R13. Through high-voltage startup, a first control signal is output to the GATE pin of the control chip U12, and a first drive signal is generated through the gallium nitride drive circuit 5 to drive the gallium nitride switching transistor Q2 to turn on. Therefore, the gallium nitride switching transistor Q2 forms a square-wave signal in the primary winding. 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; thus, connecting the auxiliary winding power supply circuit can supply power to the control chip U12, enabling 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 form of connecting the diode D9 and the resistor R22 in series can eliminate the negative voltage in the auxiliary winding, absorb the spike voltage at the same time, and use the capacitor C20 to filter out the high-frequency interference in the auxiliary winding and store energy at the same time.

[0054] In this embodiment, as Figure 2 shown, the gallium nitride drive 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, the negative pole 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 is connected to the positive pole of the diode D8;

[0058] A capacitor C16, one end of which is connected to the positive pole of the diode D8, and the other end is connected to the gate of the gallium nitride switching transistor Q2;

[0059] A resistor R15, which is connected in parallel with the capacitor C16;

[0060] A zener diode ZD1, the negative pole of which is connected to the other end of the capacitor C16;

[0061] A zener diode ZD2, the positive pole of which is connected to the positive pole of the zener diode ZD1, and the negative pole is connected to the signal ground SGND;

[0062] A capacitor C18, one end of which is connected to the negative pole of the zener diode ZD2, and the other end is connected to the VDDL pin of the control chip U12;

[0063] The resistor R19 has one end connected to the negative electrode of the voltage stabilizing diode ZD1 and the other end connected to the negative electrode of the voltage stabilizing diode 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 method of using the resistor R16 in series with the diode D8 and the two in parallel with the resistor R17 can make the gallium nitride switch Q2 open slowly and turn off quickly, eliminating the spikes of the secondary winding synchronous rectification. At the same time, the capacitor C16 is in parallel with the resistor R15 and is connected to both the voltage stabilizing diode ZD1 and the voltage stabilizing diode ZD2 to generate a stable drive voltage for the entire drive circuit and generate a negative voltage at the same time, which is more conducive to the turn-off of the gallium nitride switch Q2.

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

[0066] The resistor R25 has one end connected to one end of the auxiliary winding and the other end connected to the DEM pin of the control chip U12;

[0067] The resistor R26 has one end connected to the other end of the resistor R25 and the other end connected to the signal ground SGND;

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

[0069] Specifically, in the valley conduction circuit 6, the auxiliary coupling signal in the auxiliary winding is divided by the resistor R25 and the resistor R26. The DEM pin of the control chip U12 samples the divided voltage signal and makes the gallium nitride switch Q2 conduct near the valley in a fixed-delay manner. Such a method can greatly improve the conversion efficiency of the system, reduce the switching loss, and make the entire circuit reach a quasi-resonant state.

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

[0071] The synchronous rectification chip U7 has its input end connected to one end of the secondary winding,

[0072] The electrolytic capacitor C4 has one end connected to the output end of the synchronous rectification chip U7, the other end connected to the other end of the secondary winding, and connected to the analog ground AGND;

[0073] The capacitor C5 is connected in parallel with the electrolytic capacitor C4;

[0074] The common mode inductor U5 has one set of ports connected to the capacitor C5, and the other set of ports outputs the output signal and is connected to the analog ground AGND.

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

[0076] In this embodiment, as Figure 3 shown, the fast - charging protocol detection circuit 8 includes an interface chip USB1 and a fast - charging protocol chip U6 connected to each other; among them, 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 and 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 - charging protocol detection circuit 8 further 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; where, the negative electrode of the diode D2 and one end of the capacitor C6 are both connected to the CC1 pin of the fast - charging protocol chip U6, and the positive electrode of the diode D2 and the other end of the capacitor C6 are respectively connected to the power ground PGND and the analog ground AGND;

[0081] A diode D3 and a capacitor C10 connected to the CC2 pin of the fast - charging protocol chip U6; where, the negative electrode of the diode D3 and one end of the capacitor C10 are both connected to the CC2 pin of the fast - charging protocol chip U6, and the positive electrode of the diode D3 and the other end of the capacitor C10 are respectively connected to the power ground PGND and the analog ground AGND;

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

[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 [] is an NMOS transistor for the control protocol, and its function is: if the voltage in the output protocol is the same as the voltage output by the power supply, the NMOS transistor is turned on, otherwise it is turned off. The CV (constant voltage) loop compensation is realized through the series circuit of the resistor R10 and the capacitor C13 between the VFB pin and the OPTO / FB pin, and the CC (constant current) loop compensation is realized through the series circuit of the resistor R12 and the capacitor C15 between the I FB pin and the OPTO / FB pin; at the same time, the resistor R5 is set to 36K, and the maximum output power is 100W; the CC1 pin, CC2 pin, DP pin and DM pin all adopt differential routing to ensure signal stability. Through setting, the system can support multiple fast charging protocols such as QC, SCP, AFC, PD, FCP, etc.

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

[0088] A resistor R20, one end of which is connected to the output rectifying and filtering circuit 7 to access the output signal; [[ID=?]]

[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 charging protocol detection circuit 8 to access the output feedback signal;

[0090] An optocoupler U13, the anode of the light emitting end is connected between the resistor R20 and the resistor R24, the cathode 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] A capacitor C24, which is connected between the collector and the emitter of the light receiving end of the optocoupler U13.

[0092] Specifically, the main function of the feedback circuit 9 is to maintain the stability of the output signal. It adjusts the change of the output signal through negative feedback and quickly adjusts the working state of the internal circuit to offset this influence. Generally speaking, if the voltage of the output signal is too high, the feedback circuit 9 feeds back to the control chip U12 that the voltage of the output signal is too high, and then the control chip U12 can reduce its own working frequency to lower the voltage of the output signal. Similarly, if the voltage of the output signal is too low, it will increase the working frequency.

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

[0094] An RCD spike absorption circuit 10, connected to both ends of the primary coil, for absorbing the spike voltage formed in the primary coil due to leakage inductance;

[0095] As Figure 2 shown, the RCD spike 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] A diode D6, the negative electrode of which is connected to the other end of the heat dissipation resistor U10 and the other end of the heat dissipation resistor U11, and the positive electrode of which is connected to the other end of the primary coil.

[0102] Specifically, the RCD spike absorption circuit is used to absorb the spikes generated by the leakage inductance of the transformer to prevent the influence of the spike high voltage on the gallium nitride switching transistor Q2.

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

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

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

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

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

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

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

[0110] A capacitor C22, 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 at the same time, the operating current of the system can be determined by sampling the voltage across the resistor R23. The resistors R2, R3, and R4 are sampling resistors. After the signal flowing through the gallium nitride switch Q2 reaches the signal ground SGND, it then flows through the resistors R2, R3, and R4 and finally enters the common ground GND; the resistors R2, R3, and R4 are used to detect the magnitude of the system current so that the control chip U12 controls the operation of the gallium nitride switch 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 are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within 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 rectifier and filter circuit, connected between the AC signal and a common ground, for rectifying and filtering 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 rectifier and filter circuit; a gallium nitride switching tube, having a gate alternately connected to a first drive signal and a second drive signal, a drain connected to the other end of the primary winding, and a source connected to a signal ground, and configured 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 the square wave signal in the primary winding is further coupled to the auxiliary winding and the secondary winding, thereby generating 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 rectifier and filter circuit, and configured to generate a high-voltage starting signal according to the DC signal; a power supply circuit, connected to one end of the auxiliary winding, and configured to generate a main control power supply signal according to the auxiliary coupling signal; a main control circuit connected to the high-voltage startup circuit and the power supply circuit, configured to start operation under the action of the high-voltage startup signal, and then operate normally under the action of the main control power supply signal, and alternately output a first control signal and a second control signal in the working state; a gallium nitride driving circuit, connected to the main control circuit and the gallium nitride switching transistor, 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, configured to generate a valley conduction signal according to the auxiliary coupling signal, so as to cause the main control circuit to output the first control signal with a fixed delay, and further cause the gallium nitride switch to conduct in the valley 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, 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; A feedback circuit is connected to the output rectifier and filter 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, which is provided with a GATE pin and a VDDL pin; the gallium nitride drive 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; 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; 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 GaN switch tube; a resistor R15 connected in parallel to the capacitor C16; The negative electrode of the voltage regulator ZD1 is connected to the other end of the capacitor C16; The positive electrode of the voltage regulator ZD2 is connected to the positive electrode of the voltage regulator ZD1, and the negative electrode 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-stabilizing tube ZD1 and the other end connected to the cathode of the voltage-stabilizing 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 the control chip U12 is provided with a DEM pin; 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 an 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 receive 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 that are interconnected; 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; The capacitor C15 and the resistor R12 are 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 are 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 are 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: Resistor R20, one end of which is connected to the output rectifier and filter circuit to receive the output signal; 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 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 rectifier and filter circuit comprises: Common mode inductor U1, one set of ports is connected to AC power; 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 rectifier and filter circuit comprises: The input end of the synchronous rectifier chip U7 is 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 connected 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 includes: 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, connected between the common ground and the signal ground, and connected to the main control circuit, for collecting system current and transmitting the collected system current to the main control circuit; The main control circuit includes a control chip U12, and the control chip U12 is provided with a CS pin; The CS current sampling circuit includes: 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; The 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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