Processing method and device of synchronous rectification driving circuit and resonant converter

Abstract

The invention provides a processing method and device of a synchronous rectification driving circuit and a resonant converter, and relates to a synchronous rectification driving technology, and the method comprises the steps: obtaining a primary side driving signal for a primary side switching tube in a primary side circuit through a main control circuit; and acquiring a driving protection signal corresponding to the corresponding synchronous rectifier tube based on the primary side driving signal for one path of primary side switch tube. And a self-driven driving signal corresponding to the corresponding synchronous rectification tube is obtained through the synchronous rectification driving circuit. Generating a synchronous rectifier tube driving signal according to the driving protection signal and the self-driving signal; and controlling the on and off of the corresponding synchronous rectifier tube according to the synchronous rectifier tube driving signal. According to the method, the synchronous rectifier tube is turned off in time, direct connection of the upper and lower synchronous rectifier tubes of the synchronous rectifier circuit and short circuit of the secondary side of the transformer caused by drive delay turn-off are avoided, and the problem of drive direct connection of the upper and lower tubes of the synchronous rectifier tube is solved.

Description

Technical Field

[0001] The present application relates to power electronics technology, and in particular to a processing method and device for a synchronous rectification drive circuit and a resonant converter. Background Art

[0002] At present, in order to improve power efficiency, synchronous rectification replaces the diode rectification circuit in the switching power supply in most LLC resonant converters. Synchronous rectification requires a drive control signal. The drive control method of the synchronous rectification circuit is divided into two categories: self-drive and external drive. Self-drive is based on detecting the current signal of the synchronous rectification circuit. The current detection method includes sampling the drain-source voltage Vds of the synchronous rectifier, or detecting the secondary current through a current transformer and a series resistor, and then generating a synchronous rectifier drive signal through a sampling processing circuit, a logic generation circuit, and a drive circuit, or using a synchronous rectification drive IC (integrated circuit) to integrate the above circuits together, and even realize more complex functions.

[0003] However, since the drive control signal is completely dependent on the sampling of the synchronous rectification current, the current sampling signal is inaccurate and easily interfered with under conditions of low output voltage, output short circuit, dynamic jump of output load, parasitic circuit interference, etc., resulting in the inability to shut down the synchronous rectifier tube in time, which in turn causes problems such as the upper and lower tubes of the synchronous rectifier tube being driven straight through and the secondary winding of the transformer being short-circuited, which seriously endangers the reliability of the synchronous rectification circuit and is prone to machine explosion. Summary of the invention

[0004] The present application provides a processing method, a device and a resonant converter for a synchronous rectifier drive circuit, which are used to solve the technical problem of direct drive of upper and lower tubes of a synchronous rectifier tube.

[0005] In a first aspect, the present application provides a processing method of a synchronous rectification drive circuit, wherein the synchronous rectification drive circuit is located on the secondary side of a resonant converter, wherein the resonant converter includes a main control circuit, a transformer, a primary circuit located on the primary side of the transformer, and a synchronous rectification circuit located on the secondary side of the transformer; the method includes:

[0006] The primary side driving signal for one primary side switch tube in the primary side circuit is obtained through the main control circuit; wherein the primary side circuit includes multiple primary side switch tubes, the synchronous rectification circuit includes multiple synchronous rectification tubes, and each primary side switch tube has a corresponding relationship with one synchronous rectification tube;

[0007] Based on the primary driving signal for the primary switch tube, a driving protection signal corresponding to the corresponding synchronous rectifier tube is obtained; wherein the corresponding synchronous rectifier tube represents a synchronous rectifier tube corresponding to the primary switch tube;

[0008] Acquiring a self-driving drive signal corresponding to the corresponding synchronous rectifier tube through the synchronous rectifier drive circuit;

[0009] A synchronous rectifier tube driving signal is generated according to the driving protection signal and the self-driving driving signal; and the corresponding synchronous rectifier tube is controlled to be turned on and off according to the synchronous rectifier tube driving signal.

[0010] Further, the obtaining of a driving protection signal corresponding to a corresponding synchronous rectifier tube based on a primary driving signal for the primary switching tube includes:

[0011] Based on the primary driving signal for the primary switch tube, the operating frequency of the primary switch tube is monitored; and the resonant frequency of the primary circuit is obtained;

[0012] If it is determined that the operating frequency is greater than or equal to the resonant frequency, a drive protection signal corresponding to the corresponding synchronous rectifier tube is obtained through the main control circuit; wherein the turn-on time of the drive protection signal is the turn-off time of the primary drive signal of the primary switch tube, and the turn-off time is a preset delay time after the turn-on and before the turn-on time of the next cycle of the primary switch tube;

[0013] If it is determined that the operating frequency is less than the resonant frequency, then after the time period from the turn-on moment of the primary switch tube to half the resonant cycle, the drive protection signal corresponding to the corresponding synchronous rectifier tube is obtained through the main control circuit; wherein the turn-on moment of the drive protection signal is the moment when the primary drive signal of the primary switch tube is turned on for half a resonant cycle, and the turn-off moment is the preset delay time after the turn-on and before the turn-on moment of the next cycle of the primary switch tube. Further, the drive protection signal corresponding to the corresponding synchronous rectifier tube is obtained based on the primary drive signal for the primary switch tube, including:

[0014] Based on the primary drive signals for the multiple primary switch tubes, a drive protection signal corresponding to the corresponding synchronous rectifier tube is obtained, and the drive protection signal is doubled according to the number of primary switch tubes.

[0015] Further, the synchronous rectification driving circuit includes a logic circuit, and the logic circuit includes a NOT gate input terminal, a NOT gate output terminal, an AND gate input terminal, and an AND gate output terminal;

[0016] The step of generating a synchronous rectifier tube drive signal according to the drive protection signal and the self-drive drive signal comprises:

[0017] Inputting the driving protection signal into the NOT gate input terminal of the logic circuit;

[0018] Based on the connection between the output terminal of the NOT gate and the first input terminal of the AND gate of the logic circuit, the driving protection signal is input into the input terminal of the NOT gate; and the self-driving driving signal is input into the second input terminal of the AND gate;

[0019] The synchronous rectifier tube driving signal is outputted through the AND gate output terminal.

[0020] Furthermore, an OR gate for inputting a drive protection signal to the logic circuit is provided in the main control circuit; the OR gate performs an OR operation on the multiple drive protection signals, and the output of the OR gate is connected to the NOT gate input terminal of the logic circuit.

[0021] In a second aspect, the present application provides a processing device for a synchronous rectification drive circuit, wherein the synchronous rectification drive circuit is located on the secondary side of a resonant converter, wherein the resonant converter includes a main control circuit, a transformer, a primary circuit located on the primary side of the transformer, and a synchronous rectification circuit located on the secondary side of the transformer; the method includes:

[0022] A first acquisition unit, configured to acquire a primary drive signal for a primary switch tube in the primary circuit through the main control circuit; wherein the primary circuit includes a plurality of primary switch tubes, the synchronous rectification circuit includes a plurality of synchronous rectification tubes, and each primary switch tube has a corresponding relationship with one synchronous rectification tube;

[0023] A second acquisition unit is used to acquire a drive protection signal corresponding to a corresponding synchronous rectifier tube based on a primary drive signal for the primary switch tube; wherein the corresponding synchronous rectifier tube represents a synchronous rectifier tube corresponding to the primary switch tube;

[0024] A third acquisition unit, configured to acquire a self-driving signal corresponding to the corresponding synchronous rectifier tube through the synchronous rectifier drive circuit;

[0025] A generating unit, configured to generate a synchronous rectifier tube driving signal according to the driving protection signal and the self-driving driving signal;

[0026] A control unit is used to control the opening and closing of the corresponding synchronous rectifier according to the synchronous rectifier driving signal.

[0027] Furthermore, the second acquiring unit includes:

[0028] A monitoring module, configured to monitor the operating frequency of the primary switch tube based on the primary drive signal for the primary switch tube; and obtain the resonant frequency of the primary circuit;

[0029] A first acquisition module is used to acquire a drive protection signal corresponding to the corresponding synchronous rectifier tube through the main control circuit if it is determined that the operating frequency is greater than or equal to the resonant frequency; wherein the turn-on time of the drive protection signal is the turn-off time of the primary drive signal of the primary switch tube, and the turn-off time is a preset delay time after the turn-on and before the turn-on time of the next cycle of the primary switch tube;

[0030] The second acquisition module is used to obtain the drive protection signal corresponding to the corresponding synchronous rectifier tube through the main control circuit after the time period from the turn-on time of the primary switch tube to half the resonant cycle if it is determined that the operating frequency is less than the resonant frequency; wherein the turn-on time of the drive protection signal is the turn-on time of the primary drive signal of the primary switch tube for half the resonant cycle, and the turn-off time is the preset time delay after the turn-on and before the turn-on time of the next cycle of the primary switch tube.

[0031] Furthermore, the second acquisition unit is specifically used to:

[0032] Based on the primary drive signals for the multiple primary switch tubes, a drive protection signal corresponding to the corresponding synchronous rectifier tube is obtained, and the drive protection signal is doubled according to the number of primary switch tubes.

[0033] Further, the synchronous rectification driving circuit includes a logic circuit, and the logic circuit includes a NOT gate input terminal, a NOT gate output terminal, an AND gate input terminal, and an AND gate output terminal;

[0034] The generating unit comprises:

[0035] A first input module, used for inputting the driving protection signal into the NOT gate input terminal of the logic circuit;

[0036] A second input module is used to input the driving protection signal to the NOT gate input terminal based on the connection between the NOT gate output terminal and the first AND gate input terminal of the logic circuit; and input the self-driving driving signal to the second AND gate input terminal;

[0037] The output module is used to output the synchronous rectifier tube driving signal through the AND gate output terminal.

[0038] Furthermore, an OR gate for inputting a drive protection signal to the logic circuit is provided in the main control circuit; the OR gate performs an OR operation on the multiple drive protection signals, and the output of the OR gate is connected to the NOT gate input terminal of the logic circuit.

[0039] In a third aspect, the present application provides a resonant converter, the resonant converter comprising a synchronous rectification drive circuit, and the synchronous rectification drive circuit is the synchronous rectification drive circuit as described in the first aspect.

[0040] In a fourth aspect, the present application provides a resonant converter, comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the computer program, the method described in the first aspect is implemented.

[0041] In a fifth aspect, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, they are used to implement the method described in the first aspect.

[0042] In a sixth aspect, the present application provides a computer program product, including a computer program, which implements the method described in the first aspect when executed by a processor.

[0043] The present application provides a processing method, device and resonant converter of a synchronous rectification drive circuit, wherein a primary drive signal for a primary switch tube in a primary circuit is obtained through a main control circuit; wherein the primary circuit includes multiple primary switch tubes, the synchronous rectification circuit includes multiple synchronous rectifier tubes, and each primary switch tube has a corresponding relationship with one synchronous rectifier tube. Based on the primary drive signal for one primary switch tube, a drive protection signal corresponding to the corresponding synchronous rectifier tube is obtained; wherein the corresponding synchronous rectifier tube represents a synchronous rectifier tube corresponding to one primary switch tube. A self-drive drive signal corresponding to the corresponding synchronous rectifier tube is obtained through the synchronous rectification drive circuit. A synchronous rectifier tube drive signal is generated according to the drive protection signal and the self-drive drive signal; and the corresponding synchronous rectifier tube is controlled to be turned on and off according to the synchronous rectifier tube drive signal. In this solution, the primary circuit includes multiple primary switch tubes, the synchronous rectification circuit includes multiple synchronous rectifier tubes, each primary switch tube has a corresponding relationship with one synchronous rectifier tube, and one synchronous rectifier tube has a corresponding relationship with the corresponding synchronous rectification drive circuit. The primary side drive signal of any primary side switch tube of the primary side circuit is obtained through the main control circuit, and the drive protection signal corresponding to the corresponding synchronous rectifier tube is obtained based on the primary side drive signal for one primary side switch tube. The primary side drive signal is a signal that controls the opening or closing of the primary side switch tube. Then, according to the obtained drive protection signal and the self-drive drive signal, a synchronous rectifier tube drive signal is generated, and the opening and closing of the synchronous rectifier tube in the synchronous rectifier circuit is controlled according to the synchronous rectifier tube drive signal. Therefore, the drive protection signal generated by the main control circuit is matched with the self-drive drive signal of the synchronous rectifier circuit to generate a synchronous rectifier tube drive signal, and the opening and closing of the corresponding synchronous rectifier tube is timely controlled by the synchronous rectifier tube drive signal, which can improve the reliability of the synchronous rectifier circuit, optimize the performance of the circuit, and realize the function of direct protection of the synchronous rectifier tube. Compared with the existing self-driven driving technology, the synchronous rectifier tube is shut down in time, which avoids the upper and lower synchronous rectifier tubes of the synchronous rectification circuit being directly connected and the secondary side of the transformer being short-circuited due to delayed shutdown of the drive, thereby improving the reliability of the synchronous rectifier tube and the switching power supply, and solving the technical problem of the upper and lower tubes of the synchronous rectifier tube being driven directly connected. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0045] Figure 1 A circuit diagram of a processing method of an existing synchronous rectification circuit provided in an embodiment of the present application;

[0046] Figure 2 A timing diagram of a processing method of an existing synchronous rectification circuit provided in an embodiment of the present application;

[0047] Figure 3 A schematic flow chart of a processing method of a synchronous rectification driving circuit provided in an embodiment of the present application;

[0048] Figure 4 A circuit diagram of another processing method of a synchronous rectification driving circuit provided in an embodiment of the present application;

[0049] Figure 5 A circuit diagram of another processing method of a synchronous rectification driving circuit provided in an embodiment of the present application;

[0050] Figure 6 A flowchart of another processing method of a synchronous rectification driving circuit provided in an embodiment of the present application;

[0051] Figure 7 A schematic diagram of the structure of a logic circuit provided in an embodiment of the present application;

[0052] Figure 8 A circuit diagram of another processing method of a synchronous rectification driving circuit provided in an embodiment of the present application;

[0053] Fig. 9 A timing diagram of a processing method of a synchronous rectification driving circuit provided in an embodiment of the present application;

[0054] Fig.10 A timing diagram of another processing method of a synchronous rectification driving circuit provided in an embodiment of the present application;

[0055] Fig.11 A schematic diagram of a flow chart of another processing device of a synchronous rectification drive circuit provided in an embodiment of the present application;

[0056] Fig.12 A circuit diagram of another processing method of a synchronous rectification driving circuit provided in an embodiment of the present application;

[0057] Fig.13 A circuit diagram of another processing method of a synchronous rectification driving circuit provided in an embodiment of the present application;

[0058] Fig.14 A timing diagram of another processing method of a synchronous rectification driving circuit provided in an embodiment of the present application;

[0059] Fig.15 A schematic diagram of the structure of a processing device for a synchronous rectification drive circuit provided in an embodiment of the present application;

[0060] Fig.16 A schematic diagram of the structure of another processing device of a synchronous rectification drive circuit provided in an embodiment of the present application;

[0061] Fig.17 A schematic diagram of the structure of a resonant converter provided in an embodiment of the present application.

[0062] The above drawings show clear embodiments of the present disclosure, which will be described in more detail below. These drawings and text descriptions are not intended to limit the scope of the present disclosure in any way, but to illustrate the concepts of the present disclosure to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0063] Here, exemplary embodiments will be described in detail, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present disclosure.

[0064] At present, in order to improve power efficiency, synchronous rectification replaces the diode rectification circuit in the switching power supply in most LLC resonant converters. Synchronous rectification requires a drive control signal. The drive control method of the synchronous rectification circuit is divided into two categories: self-drive and external drive. Self-drive is based on detecting the current signal of the synchronous rectification circuit. The current detection method includes sampling the drain-source voltage Vds of the synchronous rectifier, or detecting the secondary current through a current transformer and a series resistor, and then generating a synchronous rectifier drive signal through a sampling processing circuit, a logic generation circuit, and a drive circuit, or using a synchronous rectification drive IC (integrated circuit) to integrate the above circuits together, and even realize more complex functions.

[0065] In one example, since the drive control signal is completely dependent on the sampling of the synchronous rectification current, the current sampling signal is inaccurate and easily interfered with under conditions of low output voltage, output short circuit, dynamic jump of output load, parasitic circuit interference, etc., resulting in the inability to shut down the synchronous rectifier tube in time, which in turn causes the upper and lower tubes of the synchronous rectifier tube to be driven straight through, the secondary winding of the transformer to be short-circuited, and other problems, which seriously endanger the reliability of the synchronous rectification circuit and are prone to machine explosion.

[0066] In one example, Figure 1 A circuit diagram of a processing method of an existing synchronous rectification circuit provided in an embodiment of the present application is shown in FIG. Figure 1As shown, the primary side of the transformer Tr adopts a full-bridge LLC resonant circuit, and the secondary side adopts a full-bridge synchronous rectifier circuit controlled by an integrated IC. The primary side of the transformer Tr includes switch tubes (Q1, Q2, Q3, Q4), resonant capacitors Cr, resonant inductors Lr, and excitation inductors Lm; the secondary side includes synchronous rectifier tubes (S1, S2, S3, S4), synchronous rectifier self-driving circuits (D1, D2, D3, D4), output capacitors Co, and output loads Ro. Since the synchronous rectifier self-driving circuits have the same structure, the synchronous rectifier tubes also have the same structure, so the following only describes the working process of the synchronous rectifier tubes Q1 and D1.

[0067] Specifically, in the LLC full-bridge circuit, the driving waveforms of the full-bridge switches Q1 and Q4 are consistent, and the driving waveforms of Q2 and Q3 are consistent; Q1 and Q4 are complementary to Q2 and Q3, and there is a dead zone between Q1 and Q4 and Q2 and Q3 to ensure safety. When the secondary circuit current of the transformer Tr flows through the synchronous rectifier tube S1 for rectification, the body diode MOS tube of the synchronous rectifier tube S1 is turned on, and the synchronous rectifier self-driving circuit D1 samples the voltage diode Vds1 on the drain of S1 and under the source of S1, and detects the body diode conduction voltage drop. When the drain-source voltage Vds1 detected by D1 is less than the conduction threshold Vth_on, the synchronous rectifier self-driving circuit D1 outputs a conduction drive signal to turn on the synchronous rectifier tube S1. At this time, the sampled drain-source voltage Vds1 is the product of the conduction resistance of the synchronous rectifier tube S1 and the current flowing through the synchronous rectifier tube S1, and the drain-source voltage Vds1 changes with the change of current. When the current decreases, the product increases accordingly. When the product increases to the turn-off threshold Vth_off, the synchronous rectifier self-driving circuit outputs a turn-off signal to turn off the synchronous rectifier drive. From the structure of the full-bridge rectifier, it can be seen that the current flowing through the synchronous rectifier tube S1 is the same as that flowing through the synchronous rectifier tube S4; then, the secondary current of the transformer Tr rotates to the synchronous rectifier tube S2 / S3 for rectification, and the working process is the same as S1 / S4. However, since the drive signal is completely dependent on the sampling of the synchronous rectifier current, under some special working conditions, due to the inaccuracy of the sampling voltage, the synchronous rectifier tube has a delayed shutdown phenomenon. For example, under the working conditions of low output voltage, output short circuit, dynamic jump of output load, intermittent conduction of synchronous rectifier current, etc., the current of synchronous rectifier S1 / S4 decreases. When the current of synchronous rectifier S1 / S4 has passed zero, but under the influence of circuit parasitic inductance and parasitic capacitance, the drain-source sampling voltage is still lower than the shutdown threshold Vth_off, causing the synchronous rectifier to continue to be turned on and unable to be turned off in time. The secondary current of the transformer begins to commutate, and the synchronous rectifier S2 / S3 begins to conduct, causing the upper and lower tubes of the synchronous rectifier to be driven directly, and the secondary winding of the transformer is short-circuited. These problems seriously endanger the reliability of the synchronous rectifier circuit and are prone to explosion. Therefore, it is necessary to improve the synchronous rectifier self-driving circuit in the LLC resonant converter.

[0068] In one example, Figure 2A timing diagram of a processing method of an existing synchronous rectification circuit provided in an embodiment of the present application, Figure 2 For Figure 1 The corresponding timing diagram is as follows: Figure 2 As shown, in the time period t0-t1, the self-driving drive signals issued by the synchronous rectifier self-driving circuits D1 and D4 are normally transmitted and shut down without delay, so the S1 and S4 synchronous rectifier tubes can be shut down in time. In the time period t2-t3, the self-driving drive signals of D2 and D3 are delayed and decreased, resulting in delayed shutdown of the S2 and S3 synchronous rectifier tubes. At t2, the D1 and D4 synchronous rectifier drive signals are normally turned on, and the D1 and D4 and D2 and D3 synchronous rectifier drive signals are simultaneously high, resulting in direct conduction of the synchronous rectifier tubes S1 and S2, S3 and S4, and the output capacitor is short-circuited through the synchronous rectifier tubes, causing damage to the synchronous rectifier tubes. The same is true for t6-t7.

[0069] The present application provides a processing method, device and resonant converter for a synchronous rectification drive circuit, aiming to solve the above technical problems in the prior art.

[0070] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0071] Figure 3 A flowchart of a processing method of a synchronous rectification drive circuit provided in an embodiment of the present application, wherein the synchronous rectification drive circuit is located on the secondary side of a resonant converter, and the resonant converter includes a main control circuit, a transformer, a primary circuit located on the primary side of the transformer, and a synchronous rectification circuit located on the secondary side of the transformer; Figure 3 As shown, the method includes:

[0072] Step 101, obtaining a primary drive signal for a primary switch tube in a primary circuit through a main control circuit; wherein the primary circuit includes multiple primary switch tubes, the synchronous rectification circuit includes multiple synchronous rectification tubes, and each primary switch tube has a corresponding relationship with one synchronous rectification tube.

[0073] Exemplarily, the execution subject of this embodiment may be a resonant converter. Figure 4 A circuit diagram of another processing method of a synchronous rectification driving circuit provided in an embodiment of the present application is shown in FIG. Figure 4As shown, the resonant converter includes a primary circuit of the primary side Tr, a synchronous rectification circuit of the secondary side, a transformer and a main control circuit. Among them, the primary circuit takes a full-bridge LLC resonant circuit as an example, and the primary circuit includes primary switch tubes (Q1, Q2, Q3, Q4), resonant inductor Lr, resonant capacitor Cr, and excitation inductor Lm; the synchronous rectification circuit takes a full-bridge synchronous rectification circuit as an example, and the synchronous rectification circuit includes synchronous rectifier tubes (S1, S2, S3, S4), synchronous rectification drive circuits (D1, D2, D3, D4), output capacitors Co, and output loads Ro. There is a corresponding relationship between the synchronous rectifier tubes and the synchronous rectification drive circuits. For example, S1 and D1 are a group, S2 and D2 are a group, and so on. Since the synchronous rectification drive circuits have the same structure, the synchronous rectifier tubes also have the same structure, so the following only describes the working process of the synchronous rectifier tubes Q1 and D1.

[0074] It should be noted that the signal generation of the main control circuit can be issued by a digital signal processor DSP, or by a microcontroller such as a single-chip microcomputer or an ARM processor. The primary circuit of the transformer includes but is not limited to LLC half-bridge and LLC full-bridge circuits; the synchronous rectification circuit of the secondary side of the transformer includes but is not limited to a half-wave synchronous rectification circuit, a full-wave synchronous rectification circuit, and a full-bridge synchronous rectification circuit. The synchronous rectification circuit can be built with discrete devices, or an IC (integrated circuit), or a combination of the two. The above-mentioned logic circuit can be built with discrete devices, or an IC (integrated circuit). The synchronous rectification circuit can drive only one synchronous rectifier tube, or it can drive multiple synchronous rectifier tubes at the same time.

[0075] In this step, the primary circuit includes multiple primary switch tubes, the synchronous rectification circuit includes multiple synchronous rectification tubes, each primary switch tube has a corresponding relationship with a synchronous rectification tube, and a synchronous rectification tube has a corresponding relationship with a corresponding synchronous rectification drive circuit. The primary drive signal of any primary switch tube of the primary circuit is obtained through the main control circuit, and the primary drive signal is a signal that controls the primary switch tube to turn on or off.

[0076] Step 102: Based on the primary driving signal for one primary switching tube, obtain a driving protection signal corresponding to a corresponding synchronous rectifier tube; wherein the corresponding synchronous rectifier tube represents a synchronous rectifier tube corresponding to one primary switching tube.

[0077] Exemplarily, according to the primary drive signal of one primary switch tube, the drive protection signal of the corresponding synchronous rectifier tube is obtained. Specifically, the resonant frequency of the primary circuit is first calculated according to the resonant inductor Lr and the resonant capacitor Cr. When the operating frequency of the primary switch tube is greater than or equal to the resonant frequency, a first primary drive signal is sent to the primary switch tube of the primary circuit through the main control circuit, and the first primary drive signal represents a shutdown signal for controlling the primary switch tube to be turned off. At this time, the drive protection signal starts to be generated when the primary switch tube is turned off, and a drive protection signal corresponding to the primary drive signal is sent to the synchronous rectifier circuit through the main control circuit. After a delay of a preset time period, the drive protection signal ends before the next drive of the primary switch tube is turned on. Alternatively, when the operating frequency of the primary switch tube is less than the resonant frequency, a second primary drive signal is sent to the primary switch tube of the primary circuit through the main control circuit, and the second primary drive signal represents a start signal for controlling the primary switch tube to be turned on. At this time, the timing starts when the primary switch tube is turned on, and a drive protection signal is generated after half a resonant cycle. The drive protection signal corresponding to the primary drive signal is sent to the synchronous rectification circuit through the main control circuit. After a delay of a preset time period, the drive protection signal ends before the primary switch tube is driven to be turned on next time.

[0078] Step 103: Obtain a self-driving signal corresponding to a corresponding synchronous rectifier tube through a synchronous rectifier driving circuit.

[0079] Exemplarily, the driving control method for the synchronous rectification circuit to obtain the self-driven driving signal is divided into two categories: self-driven and other-driven. Self-driven is a synchronous rectification driving circuit in the synchronous rectification circuit (i.e., a synchronous rectification self-driven control unit) based on detecting the current signal of the synchronous rectification circuit. The current detection method includes sampling the drain-source voltage Vds of the synchronous rectifier tube, or detecting the secondary current through a current transformer and a series resistor.

[0080] Step 104: Generate a synchronous rectifier tube drive signal according to the drive protection signal and the self-drive drive signal; and control the opening and closing of the corresponding synchronous rectifier tube according to the synchronous rectifier tube drive signal.

[0081] For example, Figure 5 A circuit diagram of another processing method of a synchronous rectification driving circuit provided in an embodiment of the present application is shown as follows: Figure 5 As shown, it includes a logic circuit and a synchronous rectification circuit, the driving protection signal and the self-driving signal are both input into the logic circuit, the output result of the logic circuit is used as the synchronous rectifier tube driving signal of the synchronous rectifier tube, and the opening and closing of the corresponding synchronous rectifier tube are controlled according to the synchronous rectifier tube driving signal.

[0082] In an embodiment of the present application, a primary drive signal for a primary switch tube in a primary circuit is obtained through a main control circuit; wherein the primary circuit includes multiple primary switch tubes, and the synchronous rectification circuit includes multiple synchronous rectifier tubes, and each primary switch tube has a corresponding relationship with one synchronous rectifier tube. Based on the primary drive signal for one primary switch tube, a drive protection signal corresponding to the corresponding synchronous rectifier tube is obtained; wherein the corresponding synchronous rectifier tube represents a synchronous rectifier tube corresponding to one primary switch tube. A self-drive drive signal corresponding to the corresponding synchronous rectifier tube is obtained through the synchronous rectification drive circuit. According to the drive protection signal and the self-drive drive signal, a synchronous rectifier tube drive signal is generated; and the opening and closing of the corresponding synchronous rectifier tube is controlled according to the synchronous rectifier tube drive signal. In this solution, the primary circuit includes multiple primary switch tubes, and the synchronous rectification circuit includes multiple synchronous rectifier tubes, and each primary switch tube has a corresponding relationship with one synchronous rectifier tube, and one synchronous rectifier tube has a corresponding relationship with the corresponding synchronous rectification drive circuit. The primary side drive signal of any primary side switch tube of the primary side circuit is obtained through the main control circuit, and the drive protection signal corresponding to the corresponding synchronous rectifier tube is obtained based on the primary side drive signal for one primary side switch tube. The primary side drive signal is a signal that controls the opening or closing of the primary side switch tube. Then, according to the obtained drive protection signal and the self-drive drive signal, a synchronous rectifier tube drive signal is generated, and the opening and closing of the synchronous rectifier tube in the synchronous rectifier circuit is controlled according to the synchronous rectifier tube drive signal. Therefore, the drive protection signal generated by the main control circuit is matched with the self-drive drive signal of the synchronous rectifier circuit to generate a synchronous rectifier tube drive signal, and the opening and closing of the corresponding synchronous rectifier tube is timely controlled by the synchronous rectifier tube drive signal, which can improve the reliability of the synchronous rectifier circuit, optimize the performance of the circuit, and realize the function of direct protection of the synchronous rectifier tube. Compared with the existing self-driving technology, it realizes the timely shutdown of the synchronous rectifier tube, avoids the delay in driving shutdown, which causes the upper and lower synchronous rectifier tubes of the synchronous rectifier circuit to be directly connected and the secondary side of the transformer to be short-circuited, thereby improving the reliability of the synchronous rectifier tube and the switching power supply, and solving the technical problem of the upper and lower tubes of the synchronous rectifier tube being directly connected.

[0083] Figure 6 A flowchart of another processing method of a synchronous rectification drive circuit provided in an embodiment of the present application, wherein the synchronous rectification drive circuit is located on the secondary side of a resonant converter, and the resonant converter includes a main control circuit, a transformer, a primary circuit located on the primary side of the transformer, and a synchronous rectification circuit located on the secondary side of the transformer; Figure 6 As shown, the method includes:

[0084] Step 201, obtaining a primary drive signal for a primary switch tube in a primary circuit through a main control circuit; wherein the primary circuit includes multiple primary switch tubes, the synchronous rectification circuit includes multiple synchronous rectification tubes, and each primary switch tube has a corresponding relationship with one synchronous rectification tube.

[0085] For example, this step can be referred to Figure 1 Step 101 in the above is not described in detail.

[0086] Step 202: Based on the primary drive signal for one primary switch tube, obtain a drive protection signal corresponding to a corresponding synchronous rectifier tube; wherein the corresponding synchronous rectifier tube represents a synchronous rectifier tube corresponding to one primary switch tube.

[0087] Step 202 includes two implementations:

[0088] A first implementation method of step 202: based on the primary drive signal for one primary switch tube, the operating frequency of the primary switch tube is monitored; and the resonant frequency of the primary circuit is obtained; if it is determined that the operating frequency is greater than or equal to the resonant frequency, the drive protection signal corresponding to the corresponding synchronous rectifier tube is obtained through the main control circuit; wherein, the turn-on moment of the drive protection signal is the turn-off moment of the primary drive signal of the primary switch tube, and the turn-off moment is a delay of a preset time after the turn-on and before the turn-on moment of the next cycle of the primary switch tube; if it is determined that the operating frequency is less than the resonant frequency, then after the turn-on moment of the primary switch tube to half the resonant cycle, the drive protection signal corresponding to the corresponding synchronous rectifier tube is obtained through the main control circuit; wherein, the turn-on moment of the drive protection signal is the turn-on moment of the primary drive signal of the primary switch tube for half the resonant cycle, and the turn-off moment is a delay of a preset time after the turn-on and before the turn-on moment of the next cycle of the primary switch tube.

[0089] A second implementation of step 202 is: based on the primary drive signals for multiple primary switch tubes, a drive protection signal corresponding to the corresponding synchronous rectifier tube is obtained, and the drive protection signal is doubled according to the number of primary switch tubes.

[0090] Exemplarily, in a first implementation, based on the primary drive signal of a primary switch tube, the operating frequency of the primary switch tube is monitored, and the resonant frequency in the primary circuit is obtained, and the resonant frequency is calculated based on the resonant inductance Lr and the resonant capacitance Cr of the primary circuit. If it is determined that the operating frequency is greater than or equal to the resonant frequency, the drive protection signal corresponding to the corresponding synchronous rectifier tube is obtained through the main control circuit, and the turn-on time of the drive protection signal is the turn-off time of the primary drive signal of the primary switch tube, and the turn-off time is a delay of a preset time after the turn-on and before the turn-on time of the next cycle of the primary switch tube. If it is determined that the operating frequency is less than the resonant frequency, the drive protection signal corresponding to the corresponding synchronous rectifier tube is obtained through the main control circuit after the turn-on time of the primary switch tube to half the resonant cycle. The turn-on time of the drive protection signal is the turn-on time of the primary drive signal of the primary switch tube for half the resonant cycle, and the turn-off time is a delay of a preset time after the turn-on and before the turn-on time of the next cycle of the primary switch tube.

[0091] In a second implementation, based on the primary drive signals for multiple primary switch tubes, a drive protection signal corresponding to the corresponding synchronous rectifier tube is obtained, and the drive protection signal is doubled according to the number of primary switch tubes.

[0092] Step 203: Obtain a self-driving signal corresponding to the corresponding synchronous rectifier tube through the synchronous rectifier driving circuit.

[0093] For example, this step can be referred to Figure 1 Step 103 in the above is not described in detail.

[0094] Step 204: The synchronous rectification driving circuit includes a logic circuit, and the logic circuit includes a NOT gate input terminal, a NOT gate output terminal, an AND gate input terminal, and an AND gate output terminal; the driving protection signal is input into the NOT gate input terminal of the logic circuit.

[0095] Exemplarily, the synchronous rectification circuit includes a logic circuit, Figure 7 A schematic diagram of a logic circuit provided in an embodiment of the present application is shown in FIG. Figure 7 As shown, the logic circuit is composed of a NOT gate and an AND gate, the NOT gate includes a NOT gate input terminal a1 and a NOT gate output terminal a2, and the AND gate includes a first AND gate input terminal b1, a second AND gate input terminal b2, and an AND gate output terminal b3. The driving protection signal is input to the NOT gate input terminal a1 of the logic circuit.

[0096] Step 205 , based on the connection between the output terminal of the NOT gate and the first input terminal of the AND gate of the logic circuit, the driving protection signal is input to the input terminal of the NOT gate; and the self-driving driving signal is input to the second input terminal of the AND gate.

[0097] Exemplarily, since the NOT gate output terminal a2 is connected to the first AND gate input terminal b1 of the logic circuit, the drive protection signal is input to the NOT gate input terminal a1, and then the NOT gate output terminal a2 can output the drive protection signal to the first AND gate input terminal b1; and the self-driven drive signal is input to the second AND gate input terminal b2.

[0098] Step 206: output the synchronous rectifier tube driving signal through the output terminal of the AND gate.

[0099] Exemplarily, since the first AND gate input terminal b1 obtains the driving protection signal and the second AND gate input terminal b2 obtains the self-driving driving signal, the synchronous rectifier tube driving signal is output through the AND gate output terminal b3.

[0100] Step 207: Control the opening and closing of the corresponding synchronous rectifier tube according to the synchronous rectifier tube driving signal.

[0101] In one example, an OR gate for inputting a driving protection signal to a logic circuit is provided in the main control circuit; the OR gate performs an OR operation on multiple driving protection signals, and an output of the OR gate is connected to a NOT gate input terminal of the logic circuit.

[0102] Exemplarily, the switching of a corresponding synchronous rectifier tube can be controlled by a synchronous rectifier tube driving signal.

[0103] For example, if Figure 4 As shown, if the synchronous rectification circuit drives any synchronous rectifier tube (S1, S4) connected to the synchronous rectification drive circuit (D1, D4), the main control circuit can send a drive protection signal, and generate a synchronous rectifier tube drive signal according to the drive protection signal and the self-drive drive signal of the synchronous rectification drive circuit corresponding to the drive protection signal. Then, according to the generated synchronous rectifier tube drive signal, the opening and closing of the synchronous rectifier tube (S1, S4) connected to the synchronous rectification drive circuit is controlled.

[0104] Figure 8 A circuit diagram of another processing method of a synchronous rectification driving circuit provided in an embodiment of the present application is shown as follows: Figure 8 As shown, an OR gate for inputting a drive protection signal to the logic circuit is provided in the main control circuit, and the two drive protection signals are logically ORed. Only one path is needed to implement the above drive direct processing method. At this time, the main control circuit can only send one drive protection signal, and generate a synchronous rectifier tube drive signal according to one drive protection signal and a self-drive drive signal of a synchronous rectifier drive circuit corresponding to the drive protection signal. Then, according to the generated synchronous rectifier tube drive signal, the opening and closing of the synchronous rectifier tube connected to the synchronous rectifier drive circuit is controlled. It should be noted that the disadvantage of this method is that the pulse width of the drive protection signal needs to be smaller than the dead zone driven by the primary switch tube, otherwise the synchronous rectifier tube cannot be turned on normally.

[0105] Fig. 9 A timing diagram of a processing method of a synchronous rectification driving circuit provided in an embodiment of the present application, Fig. 9 For Figure 8 The corresponding timing diagram is as follows: Fig. 9 As shown, at time t0, the primary drive signals of the primary switch tubes Q1 and Q4 are at a low level, and the primary drive signals of the primary switch tubes Q2 and Q3 are at a low level. Therefore, at one moment, only one drive protection signal and one synchronous rectifier tube drive signal can be obtained, and thus only one synchronous rectifier tube can be controlled.

[0106] Therefore, this step realizes the timely shutdown of the synchronous rectification circuit when the synchronous rectification drive circuit fails to shut down in time, avoiding delayed shutdown of the drive, which causes the upper and lower synchronous rectifiers of the synchronous rectification circuit to be directly connected and the secondary side of the transformer to be short-circuited, thereby improving the reliability of the synchronous rectifier and the switching power supply.

[0107] In an embodiment of the present application, a primary drive signal for a primary switch tube in a primary circuit is obtained through a main control circuit; wherein the primary circuit includes multiple primary switch tubes, and the synchronous rectification circuit includes multiple synchronous rectifier tubes, and each primary switch tube has a corresponding relationship with a synchronous rectifier tube. Based on the primary drive signal for a primary switch tube, a drive protection signal corresponding to the corresponding synchronous rectifier tube is obtained; wherein the corresponding synchronous rectifier tube represents a synchronous rectifier tube corresponding to the primary switch tube. A self-drive drive signal corresponding to the corresponding synchronous rectifier tube is obtained through a synchronous rectification drive circuit. The synchronous rectification drive circuit includes a logic circuit, and the logic circuit includes a NOT gate input terminal, a NOT gate output terminal, an AND gate input terminal, and an AND gate output terminal; the drive protection signal is input to the NOT gate input terminal of the logic circuit. Based on the NOT gate output terminal being connected to the first AND gate input terminal of the logic circuit, the drive protection signal is input to the NOT gate input terminal; and the self-drive drive signal is input to the second AND gate input terminal. The synchronous rectifier tube drive signal is output through the AND gate output terminal. The corresponding synchronous rectifier tube is controlled to be turned on and off according to the synchronous rectifier tube drive signal. Therefore, by using the driving protection signal generated by the main control circuit in conjunction with the self-driving driving signal of the synchronous rectifier circuit, a synchronous rectifier driving signal is generated, and the corresponding synchronous rectifier is timely controlled to be turned on and off through the synchronous rectifier driving signal, which can improve the reliability of the synchronous rectifier circuit, optimize the performance of the circuit, and realize the function of direct protection of the synchronous rectifier. Compared with the existing self-driving driving technology, it realizes the timely shutdown of the synchronous rectifier, avoids the direct circuit of the upper and lower synchronous rectifiers of the synchronous rectifier circuit and the short circuit of the secondary side of the transformer caused by delayed shutdown of the drive, thereby improving the reliability of the synchronous rectifier and the switching power supply, and solving the technical problem of the direct circuit of the upper and lower synchronous rectifiers. It realizes the timely shutdown of the synchronous rectifier.

[0108] For example, Fig.10 A timing diagram of another processing method of a synchronous rectification driving circuit provided in an embodiment of the present application, Fig.10 For Figure 4 The corresponding timing diagram is as follows: Fig.10 As shown in the figure, at t2, the rise time of the S1 and S4 drive protection signals is consistent with the turn-off time of the switch tubes Q1 and Q4 on the primary side of the transformer, and the fall time is appropriately delayed and turned off before the next turn-on of the primary side switch tube, which is t4 in the figure. In this way, during the time period t2-t3, the drive protection signal is high, the self-drive signal is high, and the logic circuit output is low. Therefore, the synchronous rectifier is turned off at t2 and is not turned on again until the next switching cycle. The delayed shutdown caused by the high level of the synchronous rectifier self-drive signal during the t2-t3 time period is avoided. At the same time, since S1, S4 and S2, S3 are complementary, timely shutdown prevents the upper and lower tubes of the synchronous rectifier from being directly connected and the secondary side of the transformer from being short-circuited. If there is no drive protection signal, such as Figure 2 In the time periods t2-t3 and t6-t7 shown, the self-driving signals sent by D2 and D3 mistakenly send out high levels. In this time period, the synchronous rectifier tubes S1, S4 and S2, S3 are driven at high levels at the same time, which will cause the upper and lower tubes of the synchronous rectifier tubes to be directly connected, and the tubes will be damaged when the current is too large.

[0109] For example, Fig.11 A flowchart of another processing device for a synchronous rectification driving circuit provided in an embodiment of the present application is shown in FIG. Fig.11 As shown, the method includes: starting; generating a driving protection signal corresponding to the synchronous rectifier tube based on the primary driving signal of the primary switching tube; the synchronous rectification driving circuit generates a self-driving driving signal; performing logical operations on the driving protection signal and the self-driving driving signal to generate a synchronous rectifier tube driving signal; controlling the driving on and off of the synchronous rectifier tube according to the synchronous rectifier tube driving signal; and ending.

[0110] from Fig.11 It can be seen that this method obtains the primary drive signal of the primary switch tube corresponding to the synchronous rectifier switch tube, and generates the drive protection signal of the corresponding synchronous rectifier tube based on the on or off state of the primary switch tube. Fig.10 It can be seen from the t0 moment in that the rising edge time of the drive protection signal is earlier than or equal to the drive closing time of the primary switch tube. After the preset time, the drive protection signal drops. The synchronous rectifier tube drive signal is generated according to the drive protection signal and the self-drive drive signal. And the opening and closing of the synchronous rectifier tube is controlled according to the synchronous rectifier tube drive signal. Since the drive protection signal can avoid the influence of the delayed shutdown of the self-drive drive signal, the drive shutdown time is adjusted, which effectively avoids the direct connection of the upper and lower tubes and the short circuit of the secondary side of the transformer caused by the delayed shutdown of the synchronous rectifier tube, and improves the reliability of the synchronous rectification circuit.

[0111] For example, Fig.12 A circuit diagram of another processing method of a synchronous rectification driving circuit provided in an embodiment of the present application is shown as follows: Fig.12 As shown, it includes the primary circuit of the primary side Tr, the synchronous rectification circuit of the secondary side, the transformer and the main control circuit. Among them, the synchronous rectification circuit of the secondary side of the transformer is a full-wave synchronous rectification circuit, and the synchronous rectification circuit includes a synchronous rectifier tube (S1, S2), a synchronous rectification drive circuit (D1, D2), an output capacitor Co, and an output load Ro; the primary circuit includes a primary switch tube (Q1, Q2), a resonant inductor Lr, a resonant capacitor Cr, and an excitation inductor Lm.

[0112] For example, Fig.13 A circuit diagram of another processing method of a synchronous rectification driving circuit provided in an embodiment of the present application, such as Fig.13 As shown, the main control circuit generates a driving protection signal with a frequency that is a multiple of the frequency calculated by the primary driving signal of the primary switch tube of the transformer (DCDC) by a suitable method or by using other circuits or software functions. Figure 8 , saving an OR gate and occupying one less output of the main control circuit.

[0113] Fig.14 A timing diagram of another processing method of a synchronous rectification driving circuit provided in an embodiment of the present application, Fig.14 For Fig.13 The corresponding timing diagram is as follows: Fig.14 As shown, at t2, the rise time of the S1 and S4 drive protection signals is consistent with the turn-off time of the primary switch tubes Q1 and Q4 of the primary circuit, and the fall time is appropriately delayed and turned off before the next turn-on of the primary switch tube, which is t4 in the figure. In this way, during the t2-t3 time period, the drive protection signal is high, the self-drive signal is high, and the logic circuit output is low. Therefore, the synchronous rectifier tube is turned off at t2 and is not turned on again until the next switching cycle arrives. The delayed turn-off caused by the high level of the self-drive signal of the synchronous rectifier tube during the t2-t3 time period is avoided. At the same time, since S1, S4 and S2, S3 are complementary, timely turn-off prevents the upper and lower tubes of the synchronous rectifier tube from being directly connected and the secondary side of the transformer from being short-circuited.

[0114] Fig.15 A structural schematic diagram of a processing device for a synchronous rectification drive circuit provided in an embodiment of the present application, wherein the synchronous rectification drive circuit is located on the secondary side of a resonant converter, and the resonant converter includes a main control circuit, a transformer, a primary circuit located on the primary side of the transformer, and a synchronous rectification circuit located on the secondary side of the transformer; Fig.15 As shown, the device comprises:

[0115] The first acquisition unit 31 is used to acquire a primary driving signal for a primary switch tube in the primary circuit through a main control circuit; wherein the primary circuit includes multiple primary switch tubes, the synchronous rectification circuit includes multiple synchronous rectification tubes, and each primary switch tube has a corresponding relationship with one synchronous rectification tube.

[0116] The second acquisition unit 32 is used to acquire a drive protection signal corresponding to a corresponding synchronous rectifier tube based on a primary drive signal for a primary switch tube; wherein the corresponding synchronous rectifier tube represents a synchronous rectifier tube corresponding to a primary switch tube.

[0117] The third acquisition unit 33 is used to acquire a self-driving signal corresponding to a corresponding synchronous rectifier tube through a synchronous rectifier drive circuit.

[0118] The generating unit 34 is used to generate a synchronous rectifier tube driving signal according to the driving protection signal and the self-driving driving signal.

[0119] The control unit 35 is used to control the opening and closing of the corresponding synchronous rectifier according to the synchronous rectifier driving signal.

[0120] The device of this embodiment can execute the technical solution in the above method. Its specific implementation process and technical principles are the same and will not be repeated here.

[0121] Fig.16 A schematic diagram of the structure of another processing device of a synchronous rectification driving circuit provided in an embodiment of the present application is provided. Fig.15 Based on the embodiment shown, Fig.16 As shown, the second acquisition unit 32 includes:

[0122] The monitoring module 321 is used to monitor the operating frequency of the primary switch tube based on the primary drive signal for one primary switch tube, and obtain the resonant frequency of the primary circuit.

[0123] The first acquisition module 322 is used to obtain the drive protection signal corresponding to the corresponding synchronous rectifier tube through the main control circuit if it is determined that the operating frequency is greater than or equal to the resonant frequency; wherein the turn-on time of the drive protection signal is the turn-off time of the primary drive signal of the primary switch tube, and the turn-off time is delayed by a preset time after the turn-on and before the turn-on time of the next cycle of the primary switch tube.

[0124] The second acquisition module 323 is used to obtain the drive protection signal corresponding to the corresponding synchronous rectifier tube through the main control circuit after the time period from the turn-on time of the primary switch tube to half the resonant cycle if it is determined that the operating frequency is less than the resonant frequency; wherein the turn-on time of the drive protection signal is the time when the primary drive signal of the primary switch tube is turned on for half the resonant cycle, and the turn-off time is a preset delay time after the turn-on and before the turn-on time of the next cycle of the primary switch tube.

[0125] In one example, the second obtaining unit 32 is specifically configured to:

[0126] Based on the primary driving signals for multiple primary switching tubes, a driving protection signal corresponding to the corresponding synchronous rectifier tube is obtained, and the driving protection signal is multiplied according to the number of primary switching tubes.

[0127] In one example, the synchronous rectification driving circuit includes a logic circuit, and the logic circuit includes a NOT gate input terminal, a NOT gate output terminal, an AND gate input terminal, and an AND gate output terminal;

[0128] The generating unit 34 includes:

[0129] The first input module 341 is used to input the driving protection signal into the NOT gate input terminal of the logic circuit.

[0130] The second input module 342 is used to input the driving protection signal into the NOT gate input terminal based on the connection between the NOT gate output terminal and the first AND gate input terminal of the logic circuit; and input the self-driving driving signal into the second AND gate input terminal.

[0131] The output module 343 is used to output the synchronous rectifier tube driving signal through the AND gate output terminal.

[0132] In one example, an OR gate for inputting a driving protection signal to a logic circuit is provided in the main control circuit; the OR gate performs an OR operation on multiple driving protection signals, and an output of the OR gate is connected to a NOT gate input terminal of the logic circuit.

[0133] The device of this embodiment can execute the technical solution in the above method. Its specific implementation process and technical principles are the same and will not be repeated here.

[0134] The present application provides a resonant converter, which includes a synchronous rectification drive circuit, and the synchronous rectification drive circuit is the synchronous rectification drive circuit pointed out in the above embodiment.

[0135] Fig.17 Schematic diagram of a resonant converter provided in an embodiment of the present application, wherein the resonant converter includes an LLC resonant converter, etc. Fig.17 As shown, the resonant converter includes: a memory 51 and a processor 52 .

[0136] The memory 51 stores a computer program that can be executed on the processor 52 .

[0137] The processor 52 is configured to execute the method provided in the above embodiment.

[0138] The resonant converter further includes a receiver 53 and a transmitter 54. The receiver 53 is used to receive instructions and data sent by an external device, and the transmitter 54 is used to send instructions and data to the external device.

[0139] The embodiment of the present application also provides a non-temporary computer-readable storage medium. When the instructions in the storage medium are executed by the processor of the transformer, the transformer can execute the method provided in the above embodiment.

[0140] An embodiment of the present application also provides a computer program product, which includes: a computer program, which is stored in a readable storage medium. At least one processor of the transformer can read the computer program from the readable storage medium, and at least one processor executes the computer program so that the transformer executes the solution provided by any of the above embodiments.

[0141] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0142] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A processing method for a synchronous rectification driving circuit, characterized in that: The synchronous rectification driving circuit is located at the secondary side of the resonant converter, and the resonant converter includes a main control circuit, a transformer, a primary circuit located at the primary side of the transformer, and a synchronous rectification circuit located at the secondary side of the transformer; the method includes The primary side driving signal for one primary side switch tube in the primary side circuit is obtained through the main control circuit; wherein the primary side circuit includes multiple primary side switch tubes, the synchronous rectification circuit includes multiple synchronous rectification tubes, and each primary side switch tube has a corresponding relationship with one synchronous rectification tube; Based on the primary driving signal for the primary switch tube, a driving protection signal corresponding to the corresponding synchronous rectifier tube is obtained; wherein the corresponding synchronous rectifier tube represents a synchronous rectifier tube corresponding to the primary switch tube; Acquiring a self-driving drive signal corresponding to the corresponding synchronous rectifier tube through the synchronous rectifier drive circuit; A synchronous rectifier tube driving signal is generated according to the driving protection signal and the self-driving driving signal; and the corresponding synchronous rectifier tube is controlled to be turned on and off according to the synchronous rectifier tube driving signal.

2. The method according to claim 1, characterized in that The step of obtaining a driving protection signal corresponding to a corresponding synchronous rectifier tube based on a primary driving signal for the primary switching tube includes: Based on the primary driving signal for the primary switch tube, the operating frequency of the primary switch tube is monitored; and the resonant frequency of the primary circuit is obtained; If it is determined that the operating frequency is greater than or equal to the resonant frequency, a drive protection signal corresponding to the corresponding synchronous rectifier tube is obtained through the main control circuit; wherein the turn-on time of the drive protection signal is the turn-off time of the primary drive signal of the primary switch tube, and the turn-off time is a preset time delay after the turn-on and before the turn-on time of the next cycle of the primary switch tube; If it is determined that the operating frequency is less than the resonant frequency, then after the time period from the turn-on moment of the primary switch tube to half the resonant cycle, the drive protection signal corresponding to the corresponding synchronous rectifier tube is obtained through the main control circuit; wherein, the turn-on moment of the drive protection signal is the moment when the primary drive signal of the primary switch tube is turned on for half the resonant cycle, and the turn-off moment is a preset time delay after the turn-on and before the turn-on moment of the next cycle of the primary switch tube.

3. The method according to claim 1, characterized in that The step of obtaining a driving protection signal corresponding to a corresponding synchronous rectifier tube based on a primary driving signal for the primary switching tube includes: Based on the primary drive signals for the multiple primary switch tubes, a drive protection signal corresponding to the corresponding synchronous rectifier tube is obtained, and the drive protection signal is doubled according to the number of primary switch tubes.

4. The method according to claim 1, characterized in that: The synchronous rectification driving circuit includes a logic circuit, and the logic circuit includes a NOT gate input terminal, a NOT gate output terminal, an AND gate input terminal, and an AND gate output terminal; The step of generating a synchronous rectifier tube drive signal according to the drive protection signal and the self-drive drive signal comprises: Inputting the driving protection signal into the NOT gate input terminal of the logic circuit; Based on the connection between the output terminal of the NOT gate and the first input terminal of the AND gate of the logic circuit, the driving protection signal is input into the input terminal of the NOT gate; and the self-driving driving signal is input into the second input terminal of the AND gate; The synchronous rectifier tube driving signal is outputted through the AND gate output terminal.

5. The method according to claim 4, characterized in that The main control circuit is provided with an OR gate for inputting a driving protection signal to the logic circuit; the OR gate performs an OR operation on the multi-channel driving protection signals, and the output of the OR gate is connected to the NOT gate input terminal of the logic circuit.

6. A processing device for a synchronous rectification driving circuit, characterized in that: The synchronous rectification driving circuit is located at the secondary side of the resonant converter, and the resonant converter includes a main control circuit, a transformer, a primary circuit located at the primary side of the transformer, and a synchronous rectification circuit located at the secondary side of the transformer; the device includes: A first acquisition unit, configured to acquire a primary drive signal for a primary switch tube in the primary circuit through the main control circuit; wherein the primary circuit includes a plurality of primary switch tubes, the synchronous rectification circuit includes a plurality of synchronous rectification tubes, and each primary switch tube has a corresponding relationship with one synchronous rectification tube; A second acquisition unit is used to acquire a drive protection signal corresponding to a corresponding synchronous rectifier tube based on a primary drive signal for the primary switch tube; wherein the corresponding synchronous rectifier tube represents a synchronous rectifier tube corresponding to the primary switch tube; A third acquisition unit, configured to acquire a self-driving signal corresponding to the corresponding synchronous rectifier tube through the synchronous rectifier drive circuit; A generating unit, configured to generate a synchronous rectifier tube driving signal according to the driving protection signal and the self-driving driving signal; A control unit is used to control the opening and closing of the corresponding synchronous rectifier according to the synchronous rectifier driving signal.

7. The device according to claim 6, characterized in that The second acquisition unit includes: A monitoring module, configured to monitor the operating frequency of the primary switch tube based on the primary drive signal for the primary switch tube; and obtain the resonant frequency of the primary circuit; A first acquisition module is used to acquire a drive protection signal corresponding to the corresponding synchronous rectifier tube through the main control circuit if it is determined that the operating frequency is greater than or equal to the resonant frequency; wherein the turn-on time of the drive protection signal is the turn-off time of the primary drive signal of the primary switch tube, and the turn-off time is a preset time delay after the turn-on and before the turn-on time of the next cycle of the primary switch tube; The second acquisition module is used to obtain the drive protection signal corresponding to the corresponding synchronous rectifier tube through the main control circuit after the time period from the turn-on time of the primary switch tube to half the resonant cycle if it is determined that the operating frequency is less than the resonant frequency; wherein the turn-on time of the drive protection signal is the turn-on time of the primary drive signal of the primary switch tube for half the resonant cycle, and the turn-off time is the preset time delay after the turn-on and before the turn-on time of the next cycle of the primary switch tube.

8. The device according to claim 6, characterized in that The second acquisition unit is specifically used to: Based on the primary drive signals for the multiple primary switch tubes, a drive protection signal corresponding to the corresponding synchronous rectifier tube is obtained, and the drive protection signal is doubled according to the number of primary switch tubes.

9. The device according to claim 6, characterized in that The synchronous rectification driving circuit includes a logic circuit, and the logic circuit includes a NOT gate input terminal, a NOT gate output terminal, an AND gate input terminal, and an AND gate output terminal; The generating unit comprises: A first input module, used for inputting the driving protection signal into the NOT gate input terminal of the logic circuit; A second input module is used to input the driving protection signal to the NOT gate input terminal based on the connection between the NOT gate output terminal and the first AND gate input terminal of the logic circuit; and input the self-driving driving signal to the second AND gate input terminal; The output module is used to output the synchronous rectifier tube driving signal through the AND gate output terminal.

10. The device according to claim 9, characterized in that The main control circuit is provided with an OR gate for inputting a driving protection signal to the logic circuit; the OR gate performs an OR operation on the multi-channel driving protection signals, and the output of the OR gate is connected to the NOT gate input terminal of the logic circuit.

11. A resonant converter, characterized in that: The resonant converter comprises a synchronous rectification drive circuit, and the synchronous rectification drive circuit is the synchronous rectification drive circuit as described in any one of claims 1-5.

12. A resonant converter, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program executable on the processor, and the processor implements the method according to any one of claims 1 to 5 when executing the computer program.

13. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 5 when executed by a processor.

14. A computer program product, characterized in that The invention comprises a computer program, which implements the method according to any one of claims 1 to 5 when being executed by a processor.

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