Secondary synchronous rectification circuit and method for switching power supply

Abstract

The present disclosure relates to a secondary synchronous rectification circuit and method for a switching power supply. The secondary synchronous rectification circuit includes: a dynamic drive circuit for determining whether to enter a dynamic response mode, and outputting a dynamic drive signal when it is determined to enter the dynamic response mode; a dynamic trigger switch tube connected to the dynamic drive circuit for turning on when receiving the dynamic drive signal to feedback the secondary dynamic response state to the primary control circuit; a secondary drive circuit for outputting a secondary rectification drive signal; a secondary switch tube connected to the secondary drive circuit for turning on and off according to the secondary rectification drive signal to perform secondary synchronous rectification, wherein the internal resistance of the dynamic trigger switch tube is greater than a predetermined resistance value. In this way, even if the primary switch tube and the secondary dynamic trigger switch tube are turned on at the same time in the switching power supply, the output current and power of the system are limited due to the large internal resistance of the dynamic trigger switch tube, so that the system will not be damaged.

Description

Technical Field

[0001] The present disclosure relates to the field of electronic circuits, and in particular, to a secondary synchronous rectification circuit and method for a switching power supply. Background Art

[0002] In a switching power supply, as the power of the switching power supply charger increases, the current continues to increase (for example, 5V / 2A to 5V / 8A). In order to improve system efficiency, the secondary can use a synchronous rectification control chip to control the MOSFET switch for rectification.

[0003] To optimize the system's dynamic undershoot effect (when the system suddenly switches from a light load to a heavy load, the primary control chip cannot keep up immediately due to its working state, which may cause the output voltage to drop significantly or even the system to fail and restart), the system needs to design a dynamic undershoot solution. One solution is to integrate a dynamic detection feedback function in the secondary synchronous rectification chip, which is fed back to the primary through the transformer. The primary control chip detects the dynamic feedback signal and responds in a timely manner. Summary of the Invention

[0004] The purpose of the present disclosure is to provide a reliable secondary synchronous rectification circuit and method for a switching power supply.

[0005] To achieve the above objectives, the present disclosure provides a secondary synchronous rectification circuit for a switching power supply, the switching power supply comprising a primary control circuit, a secondary synchronous rectification circuit, and a transformer, the primary control circuit being connected to the primary end of the transformer, the secondary synchronous rectification circuit being connected to the secondary end of the transformer, and the secondary synchronous rectification circuit comprising:

[0006] A dynamic drive circuit, configured to determine whether to enter a dynamic response mode and output a dynamic drive signal when it is determined that the dynamic response mode has been entered;

[0007] a dynamic trigger switch tube, connected to the dynamic drive circuit, and configured to be turned on when receiving the dynamic drive signal to feed back a secondary dynamic response state to the primary control circuit;

[0008] A secondary drive circuit, used for outputting a secondary rectifier drive signal;

[0009] The secondary switch tube is connected to the secondary drive circuit and is used to be turned on and off according to the secondary rectification drive signal to perform secondary synchronous rectification.

[0010] Wherein, the internal resistance of the dynamic trigger switch tube is greater than a predetermined resistance value.

[0011] Optionally, the dynamic driving circuit includes:

[0012] an output voltage detection module, configured to output a dynamic preparation signal when detecting that a voltage value of the output voltage of the secondary of the transformer is less than a predetermined voltage threshold or a rate of decrease of the voltage value of the output voltage of the secondary of the transformer is greater than a predetermined rate threshold;

[0013] a light-load determination module, configured to determine whether the secondary synchronous rectification circuit is light-loaded, and output a valid signal when it is determined to be light-loaded;

[0014] a dynamic logic processing module, connected to the output voltage detection module and the light load determination module, respectively, and configured to output a drive instruction signal according to the dynamic preparation signal and the valid signal;

[0015] The dynamic driving module is connected to the dynamic logic processing module, and is used to amplify the driving instruction signal to generate the dynamic driving signal, and output the dynamic driving signal.

[0016] Optionally, the secondary synchronous rectification circuit further includes:

[0017] A primary conduction detection module is connected to the drain of the secondary switch tube and is used to determine whether the primary switch tube in the switching power supply is turned on according to the drain voltage of the secondary switch tube, and output a dynamic termination instruction when it is determined that the primary switch tube is turned on.

[0018] The dynamic logic processing module is further configured to stop outputting the driving instruction signal when receiving the dynamic termination instruction.

[0019] Optionally, the dynamic logic processing module includes a dynamic pulse generating circuit and a dynamic pulse circulation circuit.

[0020] The dynamic pulse generating circuit is configured to output the driving instruction signal when the dynamic preparation signal and the valid signal are received simultaneously, and stop outputting the driving instruction signal when the dynamic termination instruction is received;

[0021] The dynamic pulse cycle circuit is connected to the dynamic pulse generating circuit, and is configured to output a dynamic cycle trigger signal when receiving the driving instruction signal, and stop outputting the dynamic cycle trigger signal when receiving the dynamic termination instruction;

[0022] The dynamic pulse generating circuit is further configured to output the driving instruction signal upon receiving the dynamic cycle trigger signal.

[0023] Optionally, the secondary synchronous rectification circuit further includes:

[0024] a dynamic overcurrent detection module connected to the drain of the dynamic trigger switch tube, configured to detect the drain current of the dynamic trigger switch tube and send a shutdown instruction to the dynamic pulse generating circuit when the drain current of the dynamic trigger switch tube is greater than a predetermined current threshold;

[0025] The dynamic pulse generating circuit is further configured to stop outputting the driving instruction signal when receiving the shutdown instruction.

[0026] Optionally, the dynamic logic processing module further includes a dynamic pulse time extension circuit, which is connected to the dynamic overcurrent detection module and the secondary drive circuit respectively, and is configured to:

[0027] Sending a working instruction to the dynamic overcurrent detection module so that the dynamic overcurrent detection module continues to work within the predetermined time period;

[0028] A shielding instruction is sent to the secondary drive circuit so that the secondary drive circuit does not output the secondary rectifier drive signal within the predetermined time period.

[0029] Optionally, the secondary driving circuit includes a switch sampling module, a driving logic processing module and a driving module.

[0030] The switch sampling module is connected to the drain of the secondary switch tube and is used to sample the drain current of the secondary switch tube;

[0031] The driving logic processing module is connected to the switch sampling module and is used to generate a normal driving signal according to the drain current of the secondary switch tube;

[0032] The driving module is connected to the driving logic processing module and is used to amplify the normal driving signal if the normal driving signal is valid, generate the secondary rectifier driving signal, and output the secondary rectifier driving signal.

[0033] The driving logic processing module is further connected to the dynamic logic processing module, and the dynamic logic processing module is further configured to stop outputting the driving instruction signal when the normal driving signal sent by the driving logic processing module is valid.

[0034] The present disclosure further provides a secondary synchronous rectification method for a switching power supply, the switching power supply comprising a primary control circuit, a secondary synchronous rectification circuit, and a transformer, the primary control circuit being connected to the primary end of the transformer, the secondary synchronous rectification circuit being connected to the secondary end of the transformer, the secondary synchronous rectification method comprising:

[0035] The dynamic driving circuit determines whether to enter the dynamic response mode, and outputs a dynamic driving signal when it is determined that the dynamic response mode has been entered;

[0036] The dynamic trigger switch tube is turned on when receiving the dynamic drive signal to feed back the secondary dynamic response state to the primary control circuit;

[0037] The secondary driving circuit outputs a secondary rectifier driving signal;

[0038] The secondary switch tube is turned on and off according to the secondary rectification drive signal to perform secondary synchronous rectification, wherein the internal resistance of the dynamic trigger switch tube is greater than a predetermined resistance value.

[0039] Optionally, the dynamic driving circuit determines whether to enter a dynamic response mode, and outputs a dynamic driving signal when it is determined that the dynamic response mode has been entered, including:

[0040] The output voltage detection module outputs a dynamic preparation signal when detecting that the voltage value of the output voltage of the secondary of the transformer is less than a predetermined voltage threshold or the speed at which the voltage value of the output voltage of the secondary of the transformer decreases is greater than a predetermined rate threshold;

[0041] The light load determination module determines whether the secondary synchronous rectification circuit is lightly loaded, and outputs a valid signal when it is determined to be lightly loaded;

[0042] The dynamic logic processing module outputs a driving instruction signal according to the dynamic preparation signal and the effective signal;

[0043] The dynamic driving module amplifies the driving instruction signal to generate the dynamic driving signal, and outputs the dynamic driving signal.

[0044] Optionally, the secondary synchronous rectification method further includes:

[0045] The primary conduction detection module determines whether the primary switch tube in the switching power supply is turned on according to the drain voltage of the secondary switch tube, and outputs a dynamic termination instruction when it is determined that the primary switch tube is turned on;

[0046] The dynamic logic processing module stops outputting the driving instruction signal when receiving the dynamic termination instruction.

[0047] Optionally, the dynamic logic processing module outputs a driving instruction signal according to the dynamic preparation signal and the effective signal, including:

[0048] The dynamic logic processing module includes a dynamic pulse generating circuit and a dynamic pulse circulation circuit. The dynamic pulse generating circuit outputs the driving instruction signal when receiving the dynamic preparation signal and the valid signal at the same time, and stops outputting the driving instruction signal when receiving the dynamic termination instruction.

[0049] The dynamic pulse cycle circuit outputs a dynamic cycle trigger signal when receiving the driving instruction signal, and stops outputting the dynamic cycle trigger signal when receiving the dynamic termination instruction;

[0050] The dynamic pulse generating circuit outputs the driving instruction signal when receiving the dynamic cycle trigger signal.

[0051] Optionally, the secondary synchronous rectification method further includes:

[0052] The dynamic overcurrent detection module detects the drain current of the dynamic trigger switch tube and sends a shutdown instruction to the dynamic pulse generating circuit when the drain current of the dynamic trigger switch tube is greater than a predetermined current threshold.

[0053] Wherein, upon receiving the shutdown instruction issued by the dynamic overcurrent detection module, the dynamic pulse generating circuit stops outputting the driving instruction signal.

[0054] Optionally, the secondary synchronous rectification method further includes:

[0055] When the dynamic pulse generating circuit outputs the drive instruction signal, a working instruction is sent to the dynamic overcurrent detection module so that the dynamic overcurrent detection module continues to work within the predetermined time length; and a shielding instruction is sent to the secondary drive circuit so that the secondary drive circuit does not output the secondary rectifier drive signal within the predetermined time length.

[0056] Optionally, the secondary drive circuit includes a switch sampling module, a drive logic processing module and a drive module, and the secondary drive circuit outputs a secondary rectifier drive signal, including:

[0057] The switch sampling module samples the drain current of the secondary switch tube;

[0058] The driving logic processing module generates a normal driving signal according to the drain current of the secondary switch tube;

[0059] If the normal driving signal is valid, the driving module amplifies the normal driving signal to generate the secondary rectifier driving signal and outputs the secondary rectifier driving signal.

[0060] Wherein, the method further includes: when the normal driving signal sent by the driving logic processing module is valid, the dynamic logic processing module stops outputting the driving instruction signal.

[0061] Through the above technical solution, in the secondary synchronous rectification circuit of the switching power supply, the secondary switching tube is not reused as the dynamic triggering switching tube during dynamic response. Instead, a dedicated dynamic triggering switching tube with a large internal resistance is used. In this way, even if the primary switching tube and the secondary dynamic triggering switching tube are turned on at the same time in the switching power supply, the internal resistance of the dynamic triggering switching tube is large, which limits the output current and power of the system when they are turned on at the same time. Therefore, the system will not be damaged by the excessive current caused by the simultaneous conduction, avoiding the possibility of damage due to the simultaneous conduction of the primary switching tube and the secondary dynamic triggering switching tube, thereby extending the service life of the switching power supply.

[0062] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0064] Figure 1 This is a circuit diagram of a switching power supply charger using primary control combined with secondary synchronous rectification in the related art;

[0065] Figure 2 is a block diagram of a secondary synchronous rectification circuit of a switching power supply provided by an exemplary embodiment;

[0066] Figure 3 is a structural schematic diagram of a secondary synchronous rectification circuit of a switching power supply provided by another exemplary embodiment;

[0067] Figure 4 is a structural schematic diagram of a secondary synchronous rectification circuit of a switching power supply provided by another exemplary embodiment;

[0068] Figure 5 is a structural schematic diagram of a secondary synchronous rectification circuit of a switching power supply provided by another exemplary embodiment;

[0069] Figure 6 is a schematic diagram of a normal trigger signal waveform provided by an exemplary embodiment;

[0070] Figure 7 This is a schematic diagram of a signal waveform of secondary dynamic multiple triggering provided by an exemplary embodiment;

[0071] Figure 8This is a schematic diagram of signal waveforms when the primary and secondary circuits are simultaneously turned on in a dynamic response according to an exemplary embodiment;

[0072] Figure 9 The present invention is a flowchart of a secondary synchronous rectification method of a switching power supply provided by an exemplary embodiment. DETAILED DESCRIPTION

[0073] The following describes the specific embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.

[0074] Figure 1 This is a circuit diagram of a switching power supply charger that uses primary control combined with secondary synchronous rectification in related technology. Figure 1 As shown, the secondary uses a synchronous rectification control chip to control the primary switching transistor for rectification. The secondary synchronous rectification control chip integrates dynamic detection and feedback functionality, which is fed back to the primary via a transformer. The primary control chip detects the dynamic feedback signal and responds promptly. Specifically, the synchronous rectification control chip includes an output voltage terminal (VCC), a ground terminal (GND), and a feedback terminal (VD).

[0075] In the solution disclosed herein, the switching power supply includes a primary control circuit, a secondary synchronous rectification circuit and a transformer. The primary control circuit is connected to the primary end of the transformer, and the secondary synchronous rectification circuit is connected to the secondary end of the transformer. Figure 2 FIG. 1 is a block diagram of a secondary synchronous rectification circuit provided by an exemplary embodiment. Figure 2 As shown, the secondary synchronous rectification circuit 100 may include a dynamic driving circuit 10 , a dynamic triggering switch tube 20 , a secondary driving circuit 30 and a secondary switch tube 40 .

[0076] The dynamic driving circuit 10 is used to determine whether to enter the dynamic response mode, and output a dynamic driving signal when it is determined that the dynamic response mode has been entered.

[0077] The dynamic trigger switch tube 20 is connected to the dynamic drive circuit 10 and is configured to be turned on when receiving a dynamic drive signal so as to feed back the secondary dynamic response state to the primary control circuit.

[0078] The secondary driving circuit 30 is configured to output a secondary rectifier driving signal.

[0079] The secondary switch tube 40 is connected to the secondary drive circuit 30 and is configured to be turned on and off according to a secondary rectification drive signal to perform secondary synchronous rectification.

[0080] Dynamic drive circuit 10 can utilize methods known in the related art to determine whether to enter dynamic response mode. Compared to the related art, dynamic trigger switch 20 is a newly added switch specifically used to provide feedback on the secondary dynamic response state. Secondary drive circuit 30 can utilize methods known in the related art to output a secondary rectifier drive signal.

[0081] The primary control circuit can be Figure 1 The primary control chip in the above secondary synchronous rectification circuit can be Figure 1 The synchronous rectification control chip in the .

[0082] The internal resistance of the dynamic trigger switch is greater than a predetermined resistance value. For example, the predetermined resistance value may be one order of magnitude greater than the internal resistance of the secondary switch, so that the current of the dynamic trigger switch is one order of magnitude smaller than the current of the secondary switch.

[0083] Through the above technical solution, in the secondary synchronous rectification circuit of the switching power supply, the secondary switching tube is not reused as the dynamic triggering switching tube during dynamic response. Instead, a dedicated dynamic triggering switching tube with a large internal resistance is used. In this way, even if the primary switching tube and the secondary dynamic triggering switching tube are turned on at the same time in the switching power supply, the internal resistance of the dynamic triggering switching tube is large, which limits the output current and power of the system when they are turned on at the same time. Therefore, the system will not be damaged by the excessive current caused by the simultaneous conduction, avoiding the possibility of damage due to the simultaneous conduction of the primary switching tube and the secondary dynamic triggering switching tube, thereby extending the service life of the switching power supply.

[0084] Figure 3 FIG. 1 is a structural diagram of a secondary synchronous rectification circuit of a switching power supply provided by another exemplary embodiment. Figure 3 As shown, the dynamic driving circuit 10 may include an output voltage detection module 11 , a light load determination module 12 , a dynamic logic processing module 13 and a dynamic driving module 14 .

[0085] The output voltage detection module 11 is configured to output a dynamic preparation signal undershoot when detecting that the voltage value of the output voltage of the transformer secondary is less than a predetermined voltage threshold or the speed at which the voltage value of the output voltage of the transformer secondary decreases is greater than a predetermined rate threshold.

[0086] The light load determination module 12 is used to determine whether the secondary synchronous rectification circuit is lightly loaded and output a valid signal LL when it is determined to be lightly loaded. For example, the light load determination module 12 can determine the load state by sampling the period of the normal drive signal DRV or the duration of the shutdown signal. When the period is not less than a certain value or the shutdown time is greater than a certain value, it can be determined to be lightly loaded and the valid LL signal is output. Only when the light load state is reached can the dynamic mode be triggered.

[0087] The dynamic logic processing module 13 is connected to the output voltage detection module 11 and the light load determination module 12 respectively, and is used to output the driving instruction signal DP0 according to the dynamic preparation signal undershoot and the valid signal LL (performing logic processing).

[0088] Dynamic drive module 14 is connected to dynamic logic processing module 13 and is configured to amplify drive command signal DP0 to generate and output dynamic drive signal DP. Specifically, dynamic drive module 14 increases the drive capability of drive command signal DP0, outputs signal DP to drive dynamic trigger switch 20 to switch, and feeds the secondary dynamic signal back to the primary control circuit.

[0089] exist Figure 3 In the embodiment, the secondary driving circuit 30 may include a switch sampling module 31 , a driving logic processing module 32 and a driving module 33 .

[0090] The switch sampling module 31 is connected to the drain of the secondary switch tube 40 and is used to sample the drain current of the secondary switch tube 40;

[0091] The driving logic processing module 32 is connected to the switch sampling module 31 and is used to generate a normal driving signal DRV according to the drain current of the secondary switch tube 40;

[0092] The driving module 33 is connected to the driving logic processing module 32 and is used to amplify the normal driving signal DRV if the normal driving signal DRV is valid, generate a secondary rectified driving signal VG, and output the secondary rectified driving signal VG.

[0093] The driving logic processing module 32 is further connected to the dynamic logic processing module 13 . The dynamic logic processing module 13 is further configured to stop outputting the driving instruction signal DP0 when the normal driving signal DRV sent by the driving logic processing module 32 is valid.

[0094] exist Figure 3 In the embodiment, the switch sampling module 31 samples the VD signal and generates a switching signal for the synchronous rectifier MOSFET (secondary switch tube 40). For example, after the primary switch tube is turned off, it promptly outputs an effective normal drive switch initial signal; the drive logic processing module 32 is used to process the output of the switch sampling module 31 and generate a DRV signal; the drive module 33 is used to amplify the DRV and output a signal VG to drive the secondary switch tube 40.

[0095] Among them, the secondary uses a low-power MOSFET (usually a low-power CMOS tube) as a dynamic trigger switch tube 20, and judges the voltage state of the secondary system output in the light load mode (LL is valid). When the output voltage is less than a predetermined voltage threshold or the rate of decrease of the voltage value of the output voltage of the transformer secondary is greater than a predetermined rate threshold (undershoot is valid), it is determined to enter the dynamic response mode.

[0096] The secondary synchronous rectification circuit 100 further includes a bias and enable module 50 , which is configured to provide voltage and current bias, a fault protection enable signal, and the like.

[0097] In this embodiment, the dynamic response process of the secondary synchronous rectification circuit 100 is as follows: when the light load determination module 12 determines that the system operating state is light load, and the voltage value of the output voltage of the transformer secondary is less than a predetermined voltage threshold or the rate of decrease of the voltage value of the output voltage of the transformer secondary is greater than a predetermined rate threshold, the secondary synchronous rectification circuit 100 will enter the dynamic response mode, and after being processed by the dynamic logic processing module, output the drive instruction signal DP0 to the dynamic drive module 14. The dynamic drive module 14 shields the output of the drive module 33 of the normal switching signal, so that the secondary switch tube 40 is in the off state, and then the dynamic drive module 14 outputs the dynamic drive signal DP to drive the dynamic trigger switch tube 20 to turn on for a certain period of time, and feeds back the secondary dynamic response state to the primary VFB pin ( Figure 1 In the middle, the primary control chip samples the VFB voltage change and promptly responds to adjust the system working state, increasing the system output power and preventing the system output voltage from continuing to drop.

[0098] In this embodiment, the separately provided dynamic trigger switch tube 20 has an independent dynamic driving module 14 and has better driving performance.

[0099] Figure 4 FIG. 1 is a structural diagram of a secondary synchronous rectification circuit of a switching power supply provided by another exemplary embodiment. Figure 4 As shown, the secondary synchronous rectification circuit 100 may further include a primary conduction detection module 60 .

[0100] The primary conduction detection module 60 is connected to the drain of the secondary switch tube 40 and is used to determine whether the primary switch tube in the switching power supply is turned on according to the drain voltage of the secondary switch tube 40, and output a dynamic termination instruction when it is determined that the primary switch tube is turned on.

[0101] In this embodiment, the dynamic logic processing module 13 is further configured to stop outputting the driving instruction signal DP0 upon receiving a dynamic termination instruction.

[0102] In this way, when the primary switch tube is turned on, the dynamic trigger switch tube can be turned off, thereby turning off the dynamic response.

[0103] In yet another embodiment, the dynamic logic processing module 13 may include a dynamic pulse generating circuit 131 and a dynamic pulse recycling circuit 132 .

[0104] The dynamic pulse generating circuit 131 is configured to output the driving instruction signal DP0 when receiving the dynamic preparation signal undershoot and the valid signal LL simultaneously, and stop outputting the driving instruction signal DP0 when receiving the dynamic termination instruction.

[0105] The dynamic pulse cycle circuit 132 is connected to the dynamic pulse generating circuit 131 and is configured to output a dynamic cycle trigger signal upon receiving the driving instruction signal DP0 and stop outputting the dynamic cycle trigger signal upon receiving the dynamic termination instruction.

[0106] The dynamic pulse generating circuit 131 is further configured to output a driving instruction signal DP0 upon receiving a dynamic cycle trigger signal.

[0107] The primary conduction detection module 60 can detect the drain voltage VD of the secondary switch tube 40 , and when the drain voltage VD is higher than a predetermined value for a predetermined time, it outputs an on signal to the dynamic logic processing module 13 to exit the dynamic response.

[0108] The dynamic pulse cycle circuit 132 is used to control the dynamic cycle triggering and can be terminated when the primary responds or the DRV signal is valid or dynamically invalid. In this embodiment, the dynamic logic processing module 13 can output the drive command signal DP0 while outputting the DPD signal to the dynamic overcurrent detection module 70, causing the dynamic overcurrent detection module 70 to start operating. The primary conduction detection module 60 can detect the drain voltage VD of the secondary switch tube 40 and output the corresponding control signal to the dynamic logic processing module 13 in real time. If the primary still does not respond after the secondary control chip first feeds back the dynamic signal, the secondary control chip will drive the dynamic trigger switch tube 20 to feed back the dynamic signal again (i.e., the secondary control chip will turn on the dynamic trigger switch tube 20 at a certain period) until the primary control chip responds, the secondary DRV signal is valid, or the secondary synchronous rectification control chip stops operating. In the secondary synchronous rectification circuit, the drive command signal DP0 is periodically output to turn on the dynamic trigger switch tube 20 until the primary switch tube is determined to be turned on or the secondary DRV signal is valid. In this way, multiple triggers of the dynamic mode are added, which solves the problem that the primary may not detect and respond at once due to small dynamic trigger current and weak feedback signal, ensuring safe and reliable operation of the system.

[0109] In yet another embodiment, Figure 4 As shown, the secondary synchronous rectification circuit 100 may further include a dynamic overcurrent detection module 70 .

[0110] The dynamic overcurrent detection module 70 is connected to the drain of the dynamic trigger switch tube 20, and is used to detect the drain current of the dynamic trigger switch tube 20, and send a shutdown instruction to the dynamic pulse generation circuit 131 when the drain current of the dynamic trigger switch tube 20 is greater than a predetermined current threshold.

[0111] The dynamic pulse generating circuit 131 is further configured to stop outputting the driving instruction signal DP0 upon receiving a shutdown instruction from the dynamic over-current detecting module 70 .

[0112] When the drain current of the dynamic trigger switch tube 20 detected by the dynamic overcurrent detection module 70 exceeds a predetermined current threshold, a dynamic overcurrent signal is output, for example, DP=“0” is set to turn off the dynamic trigger switch tube 20 to prevent damage to the dynamic trigger switch tube 20.

[0113] In this embodiment, when it is determined that the secondary dynamic trigger switch tube is overcurrent or the primary switch tube and the dynamic trigger switch tube 20 are turned on at the same time, the dynamic trigger switch tube 20 can be turned off in time to ensure safe and reliable operation of the system.

[0114] In yet another embodiment, Figure 4 As shown, the dynamic logic processing module 13 may further include a dynamic pulse time extension circuit 133. The dynamic pulse time extension circuit 133 is connected to the dynamic overcurrent detection module 70 and the secondary drive circuit 30 respectively. The dynamic pulse time extension circuit 133 is used to:

[0115] Sending a working instruction (DPD signal) to the dynamic overcurrent detection module 70 to enable the dynamic overcurrent detection module 70 to continue working within a predetermined time period;

[0116] A shielding instruction is sent to the secondary driving circuit 30 so that the secondary driving circuit 30 does not output the secondary rectifier driving signal within a predetermined time period.

[0117] Since there is a certain delay before the dynamic trigger switch tube 20 is completely turned off, other modules need to work normally before the dynamic trigger switch tube 20 is turned off to ensure that the dynamic trigger switch tube 20 is completely turned off.

[0118] In this embodiment, the normal operating time of the dynamic overcurrent detection module 70 can be extended, and the drive signal of the secondary switch tube 40 can be shielded. The dynamic pulse time extension circuit 133 is used to extend the dynamic pulse time to ensure that the dynamic overcurrent detection module 70 can continue to operate normally and shield the DRV signal for a period of time after the dynamic drive signal DP is invalid. In particular, in the event of dynamic overcurrent or simultaneous conduction of the primary and secondary circuits, the dynamic trigger switch tube 20 can be completely turned off to protect the system from damage.

[0119] Figure 5 3 is a structural diagram of a secondary synchronous rectification circuit of a switching power supply provided by yet another exemplary embodiment. Figure 5 Yes Figure 4 The dynamic normal trigger process is as follows (the key signal timing diagram is as follows Figure 6 shown):

[0120] (1) When the light load determination module 12 detects that the period of the DRV signal is not less than a certain set period TLL or the DRV signal is invalid for longer than a certain set time, LL = "1", and the working state is determined to be light load;

[0121] (2) When the output voltage detection module 11 detects that the VCC voltage is lower than a certain set value or the output voltage drops at a large slope, undershoot = "1" is a valid signal;

[0122] (3) When the chip is in light load state, LL = "1" and undershoot = "1", the system is determined to be in a dynamic state, and the secondary synchronous rectification chip enters the dynamic response mode;

[0123] (4) In the dynamic response state, all dynamic related module circuits start to work. The dynamic pulse generating circuit 131 outputs DP0=“1” valid signal; the dynamic pulse cycle circuit 132 starts timing cycle triggering. When the time reaches Tc( Figure 7 As shown), if the primary still has no response, the output loop control valid signal prompts the dynamic pulse generating circuit 131 to generate the DP0 = "1" valid signal again; the dynamic pulse time extension circuit 133 extends the DP0 signal and outputs the DPD signal, which can shield the normal drive DRV valid signal, so that the dynamic trigger switch tube 20 is turned off. At the same time, the dynamic overcurrent detection module 70 starts to work, detects the drain current state of the dynamic trigger switch tube 20 in real time, and outputs the dynamic overcurrent signal OC_M1. The primary conduction detection module 60 detects the primary state of the system in real time and outputs the primary turn-on signal ON_PS in real time. The signals EN, ON_PS, and DRV jointly generate the EN_DP signal to control the dynamic response process in real time. The signal generated by the DP0 = "1" valid signal and the EN_DP = "1" valid signal is buffered to generate the DP = "1" valid signal, which drives the dynamic trigger switch tube 20 to turn on;

[0124] (5) When DP = "1" is valid, the dynamic trigger switch 20 is driven to turn on. The secondary synchronous rectifier chip is dynamically triggered, and the VD voltage drops rapidly. It is coupled to the primary VFB pin through the transformer. After the primary control chip detects that the VFB voltage has changed to a certain value and DP = "0" is invalid, it promptly outputs a valid signal VG_PS = "1" to turn on the primary switch, increasing the system output power and operating frequency, preventing the system output voltage from continuing to drop, and gradually returning the voltage to normal. After the primary responds, the secondary dynamic response action ends.

[0125] During the dynamic triggering process: the dynamic overcurrent detection module 70 collects the voltage across the resistor R0 to detect the drain current of the dynamic triggering switch tube 20. When the current exceeds the predetermined current threshold, the dynamic overcurrent signal OC_M1 = "0" is output and locked, so that DP = "0", and the dynamic triggering switch tube 20 is turned off to prevent damage to the dynamic triggering switch tube 20; the primary conduction detection module 60 detects the VD voltage ( Figure 5 The VD1 voltage in the circuit is the voltage after the VD voltage passes through resistor R0, and the state of the primary switch is determined. When the secondary dynamic pulse signal DP = "1" is valid and the primary switch is turned on, the primary switch and the secondary dynamic trigger switch are simultaneously turned on. The primary turn-on detection module 60 detects the VD voltage and outputs the primary turn-on valid signal ON_PS = "0", which sets EN_DP = "0" and DP = "0", turning off the dynamic trigger switch 20 and ending the dynamic response process. This prevents simultaneous conduction of the primary and secondary, which could damage the dynamic trigger switch 20. The dynamic pulse time extension circuit 133 ensures that the dynamic overcurrent detection module 70 can continue to operate normally and shield the DRV signal for a period of time after the dynamic pulse DP is invalid, ensuring that the dynamic trigger switch 20 is completely turned off, protecting the system from damage. After the first dynamic response trigger of the secondary synchronous rectification control chip ends, if the primary control chip does not respond, the secondary synchronous rectification control chip cannot generate a normal driving DRV signal. The dynamic pulse cycle circuit 132 will again make the dynamic pulse generating circuit 131 output the driving instruction signal DP0 at a certain period Tc, and then generate the DP valid signal again to turn on the dynamic trigger switch tube 20, triggering the second dynamic, and so on. The cycle continues until the primary responds, the secondary EN_DP signal is invalid, and the DRV signal is valid. Figure 7 As shown; this can avoid the situation where the primary fails to detect the dynamic signal of the secondary feedback, resulting in failure of the overall dynamic response of the system.

[0126] Figure 6 FIG. 1 is a schematic diagram of a normal trigger signal waveform provided by an exemplary embodiment. Figure 6 As shown:

[0127] At time t1: the primary switch is turned on, VG_PS = "1", and the secondary conduction detection module 60 outputs ON_PS = "0";

[0128] At time t2: the primary switch is turned off, VG_PS = "0", and the secondary conduction detection module 60 outputs ON_PS = "1";

[0129] At time t3: DRV = "1", VG = "1", LL = "0", the secondary switch 40 is turned on;

[0130] At time t4: DRV = "0", VG = "0", the secondary switch 40 is turned off;

[0131] At t5: the working cycle of the secondary synchronous rectification control chip is not less than TLL, LL = "1", the system output changes from light load to heavy load, and the output voltage drops;

[0132] At time t6: when the output voltage of the transformer secondary is less than the predetermined voltage threshold or the rate of decrease of the output voltage of the transformer secondary is greater than the predetermined rate threshold, the output voltage detection module 11 outputs undershoot = "1", the secondary enters the dynamic response state, DP = "1", DPD = "1", the dynamic trigger switch 20 is turned on, the VD voltage drops sharply, and the VFB voltage rises;

[0133] At time t7: DP = "0", the dynamic trigger switch 20 is turned off, and the first secondary dynamic response ends;

[0134] At time t8: the primary control chip responds, VG_PS = "1", the primary switch is turned on, and the primary conduction detection module 60 outputs ON_PS = "0";

[0135] At t9: the primary switch is turned off, VG_PS = "0", and the primary conduction detection module 60 outputs ON_PS = "1";

[0136] At time t10: DRV = "1", VG = "1", LL = "0", DPD = "0", the secondary switch 40 is turned on, and the output voltage has risen;

[0137] At time t11: DRV = "1", VG = "1", the output voltage has risen to the dynamic trigger threshold voltage, and the output voltage detection module 11 outputs undershoot = "0";

[0138] At time t12: DRV = "0", VG = "0", the secondary switch tube 40 is turned off.

[0139] Figure 7 FIG. 1 is a schematic diagram of a secondary dynamic multiple triggering signal waveform provided by an exemplary embodiment. Figure 7As shown, after the first dynamic pulse trigger signal is valid DP="1", after Tc time, the primary control chip does not respond, until the Nth cycle, after the dynamic pulse trigger signal is valid DP="1", the primary responds quickly, VG_PS="1", the primary switch tube is turned on for a certain time, VG_PS="0", the primary switch tube is turned off, and then the secondary synchronous rectification control chip detects that the primary is turned off, outputs VG="1", the secondary switch tube 40 is turned on, the output voltage rises, and the dynamic response process of the secondary synchronous rectification control chip ends.

[0140] Figure 8 This is a schematic diagram of a signal waveform when the primary and secondary circuits are simultaneously turned on in a dynamic response according to an exemplary embodiment. Figure 8 As shown:

[0141] Time t1: secondary dynamic trigger, DP = "1", the dynamic trigger switch tube 20 is turned on;

[0142] At time t2: DP = "1", the dynamic trigger switch 20 is in the on state, VG_PS = "1", the primary switch is turned on, and at this time the primary switch and the dynamic trigger switch 20 are turned on at the same time;

[0143] At time t3: the dynamic triggering switch tube 20 is overcurrent, OC_M1 = "0", EN_DP = "0", DP = "0", the dynamic triggering switch tube 20 is turned off, and the secondary dynamic response ends.

[0144] The present disclosure also provides a secondary synchronous rectification method for a switching power supply, wherein the switching power supply includes a primary control circuit, a secondary synchronous rectification circuit, and a transformer, wherein the primary control circuit is connected to the primary end of the transformer, and the secondary synchronous rectification circuit is connected to the secondary end of the transformer. Figure 9 FIG. 1 is a flow chart of a secondary synchronous rectification method of a switching power supply provided by an exemplary embodiment. Figure 9 As shown, the secondary synchronous rectification method may include the following steps.

[0145] In step S101 , the dynamic driving circuit determines whether to enter a dynamic response mode, and outputs a dynamic driving signal when it is determined to enter the dynamic response mode.

[0146] In step S102 , the dynamic trigger switch is turned on upon receiving a dynamic driving signal to feed back the secondary dynamic response state to the primary control circuit.

[0147] In step S103 , the secondary driving circuit outputs a secondary rectifier driving signal.

[0148] In step S104, the secondary switching tube is turned on and off according to the secondary rectification driving signal to perform secondary synchronous rectification, wherein the internal resistance of the dynamic triggering switching tube is greater than a predetermined resistance value.

[0149] Optionally, the step (step S101) of the dynamic driving circuit determining whether to enter the dynamic response mode and outputting the dynamic driving signal when determining to enter the dynamic response mode includes:

[0150] The output voltage detection module outputs a dynamic preparation signal when detecting that the voltage value of the output voltage of the transformer secondary is less than a predetermined voltage threshold or the speed at which the voltage value of the output voltage of the transformer secondary decreases is greater than a predetermined rate threshold;

[0151] The light load determination module determines whether the secondary synchronous rectification circuit is light loaded, and outputs a valid signal when it is determined to be light loaded;

[0152] The dynamic logic processing module outputs the driving instruction signal according to the dynamic preparation signal and the effective signal;

[0153] The dynamic driving module amplifies the driving instruction signal to generate a dynamic driving signal and outputs the dynamic driving signal.

[0154] Optionally, the secondary synchronous rectification method may further include:

[0155] The primary conduction detection module determines whether the primary switch tube in the switching power supply is turned on according to the drain voltage of the secondary switch tube, and outputs a dynamic termination instruction when it is determined that the primary switch tube is turned on;

[0156] The dynamic logic processing module stops outputting the driving instruction signal when receiving the dynamic termination instruction.

[0157] Optionally, the step of the dynamic logic processing module outputting a drive instruction signal according to the dynamic preparation signal and the effective signal may include:

[0158] The dynamic logic processing module includes a dynamic pulse generating circuit and a dynamic pulse circulation circuit. The dynamic pulse generating circuit outputs a driving instruction signal when it receives a dynamic preparation signal and a valid signal at the same time, and stops outputting the driving instruction signal when it receives a dynamic termination signal.

[0159] The dynamic pulse cycle circuit outputs a dynamic cycle trigger signal when receiving a driving instruction signal, and stops outputting the dynamic cycle trigger signal when receiving a dynamic termination instruction;

[0160] The dynamic pulse generating circuit outputs a driving instruction signal when receiving a dynamic cycle trigger signal.

[0161] Optionally, the secondary synchronous rectification method may further include:

[0162] The dynamic overcurrent detection module detects the drain current of the dynamic trigger switch tube and sends a shutdown instruction to the dynamic pulse generation circuit when the drain current of the dynamic trigger switch tube is greater than a predetermined current threshold.

[0163] The dynamic pulse generating circuit stops outputting the driving instruction signal when receiving the shutdown instruction issued by the dynamic overcurrent detection module.

[0164] Optionally, the secondary synchronous rectification method may further include:

[0165] When the dynamic pulse generating circuit outputs a driving instruction signal, a working instruction is sent to the dynamic overcurrent detection module so that the dynamic overcurrent detection module continues to work within a predetermined time length; and a shielding instruction is sent to the secondary driving circuit so that the secondary driving circuit does not output a secondary rectifier driving signal within a predetermined time length.

[0166] Optionally, the secondary drive circuit includes a switch sampling module, a drive logic processing module and a drive module, and the secondary drive circuit outputs a secondary rectifier drive signal, including:

[0167] The switch sampling module samples the drain current of the secondary switch tube;

[0168] The driving logic processing module generates a normal driving signal according to the drain current of the secondary switch tube;

[0169] If the normal driving signal is valid, the driving module amplifies the normal driving signal, generates a secondary rectifier driving signal, and outputs the secondary rectifier driving signal.

[0170] The method may further include: when the normal driving signal sent by the driving logic processing module is valid, the dynamic logic processing module stops outputting the driving instruction signal.

[0171] Regarding the method in the above embodiment, the specific manner of performing the operation of each step has been described in detail in the embodiment of the secondary synchronous rectification circuit, and will not be elaborated here.

[0172] Through the above technical solution, in the secondary synchronous rectification circuit of the switching power supply, the secondary switching tube is not reused as the dynamic triggering switching tube during dynamic response. Instead, a dedicated dynamic triggering switching tube with a large internal resistance is used. In this way, even if the primary switching tube and the secondary dynamic triggering switching tube are turned on at the same time in the switching power supply, the internal resistance of the dynamic triggering switching tube is large, which limits the output current and power of the system when they are turned on at the same time. Therefore, the system will not be damaged by the excessive current caused by the simultaneous conduction, avoiding the possibility of damage due to the simultaneous conduction of the primary switching tube and the secondary dynamic triggering switching tube, thereby extending the service life of the switching power supply.

[0173] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the scope of protection of the present disclosure.

[0174] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0175] In addition, the various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A secondary synchronous rectification circuit of a switching power supply, characterized in that: The switching power supply includes a primary control circuit, a secondary synchronous rectification circuit and a transformer, wherein the primary control circuit is connected to the primary end of the transformer, the secondary synchronous rectification circuit is connected to the secondary end of the transformer, and the secondary synchronous rectification circuit includes: A dynamic drive circuit, configured to determine whether to enter a dynamic response mode and output a dynamic drive signal when it is determined that the dynamic response mode has been entered; a dynamic trigger switch tube, connected to the dynamic drive circuit, and configured to be turned on when receiving the dynamic drive signal to feed back a secondary dynamic response state to the primary control circuit; A secondary drive circuit, used for outputting a secondary rectifier drive signal; The secondary switch tube is connected to the secondary drive circuit and is used to be turned on and off according to the secondary rectification drive signal to perform secondary synchronous rectification. Wherein, the internal resistance of the dynamic trigger switch tube is greater than a predetermined resistance value; The dynamic driving circuit comprises: an output voltage detection module, configured to output a dynamic preparation signal when detecting that a voltage value of the output voltage of the secondary of the transformer is less than a predetermined voltage threshold or a rate of decrease of the voltage value of the output voltage of the secondary of the transformer is greater than a predetermined rate threshold; a light-load determination module, configured to determine whether the secondary synchronous rectification circuit is light-loaded, and output a valid signal when it is determined to be light-loaded; a dynamic logic processing module, connected to the output voltage detection module and the light load determination module, respectively, and configured to output a drive instruction signal according to the dynamic preparation signal and the valid signal; The dynamic driving module is connected to the dynamic logic processing module, and is used to amplify the driving instruction signal to generate the dynamic driving signal, and output the dynamic driving signal.

2. The secondary synchronous rectification circuit according to claim 1, wherein: The secondary synchronous rectification circuit further includes: A primary conduction detection module is connected to the drain of the secondary switch tube and is used to determine whether the primary switch tube in the switching power supply is turned on according to the drain voltage of the secondary switch tube, and output a dynamic termination instruction when it is determined that the primary switch tube is turned on. The dynamic logic processing module is further configured to stop outputting the driving instruction signal when receiving the dynamic termination instruction.

3. The secondary synchronous rectification circuit according to claim 2, characterized in that: The dynamic logic processing module includes a dynamic pulse generating circuit and a dynamic pulse circulation circuit. The dynamic pulse generating circuit is configured to output the driving instruction signal when the dynamic preparation signal and the valid signal are received simultaneously, and stop outputting the driving instruction signal when the dynamic termination instruction is received; The dynamic pulse cycle circuit is connected to the dynamic pulse generating circuit, and is configured to output a dynamic cycle trigger signal when receiving the driving instruction signal, and stop outputting the dynamic cycle trigger signal when receiving the dynamic termination instruction; The dynamic pulse generating circuit is further configured to output the driving instruction signal upon receiving the dynamic cycle trigger signal.

4. The secondary synchronous rectification circuit according to claim 3, characterized in that: The secondary synchronous rectification circuit further includes: a dynamic overcurrent detection module connected to the drain of the dynamic trigger switch tube, configured to detect the drain current of the dynamic trigger switch tube and send a shutdown instruction to the dynamic pulse generating circuit when the drain current of the dynamic trigger switch tube is greater than a predetermined current threshold; The dynamic pulse generating circuit is further configured to stop outputting the driving instruction signal when receiving the shutdown instruction.

5. The secondary synchronous rectification circuit according to claim 4, characterized in that: The dynamic logic processing module further includes a dynamic pulse time extension circuit, which is connected to the dynamic overcurrent detection module and the secondary drive circuit respectively. The dynamic pulse time extension circuit is configured to: Sending a working instruction to the dynamic overcurrent detection module so that the dynamic overcurrent detection module continues to work within a predetermined time period; A shielding instruction is sent to the secondary drive circuit so that the secondary drive circuit does not output the secondary rectifier drive signal within the predetermined time period.

6. The secondary synchronous rectification circuit according to claim 1, wherein: The secondary drive circuit includes a switch sampling module, a drive logic processing module and a drive module. The switch sampling module is connected to the drain of the secondary switch tube and is used to sample the drain current of the secondary switch tube; The driving logic processing module is connected to the switch sampling module and is used to generate a normal driving signal according to the drain current of the secondary switch tube; The driving module is connected to the driving logic processing module and is used to amplify the normal driving signal if the normal driving signal is valid, generate the secondary rectifier driving signal, and output the secondary rectifier driving signal. The driving logic processing module is further connected to the dynamic logic processing module, and the dynamic logic processing module is further configured to stop outputting the driving instruction signal when the normal driving signal sent by the driving logic processing module is valid.

7. A secondary synchronous rectification method for a switching power supply, characterized in that: The switching power supply includes a primary control circuit, a secondary synchronous rectification circuit, and a transformer, wherein the primary control circuit is connected to the primary end of the transformer, and the secondary synchronous rectification circuit is connected to the secondary end of the transformer. The secondary synchronous rectification method includes: The dynamic driving circuit determines whether to enter the dynamic response mode, and outputs a dynamic driving signal when it is determined that the dynamic response mode has been entered; The dynamic trigger switch tube is turned on when receiving the dynamic drive signal to feed back the secondary dynamic response state to the primary control circuit; The secondary driving circuit outputs a secondary rectifier driving signal; The secondary switch tube is turned on and off according to the secondary rectification drive signal to perform secondary synchronous rectification, wherein the internal resistance of the dynamically triggered switch tube is greater than a predetermined resistance value; The dynamic driving circuit determines whether to enter the dynamic response mode, and outputs a dynamic driving signal when it is determined to enter the dynamic response mode, including: The output voltage detection module outputs a dynamic preparation signal when detecting that the voltage value of the output voltage of the secondary of the transformer is less than a predetermined voltage threshold or the speed at which the voltage value of the output voltage of the secondary of the transformer decreases is greater than a predetermined rate threshold; The light load determination module determines whether the secondary synchronous rectification circuit is lightly loaded, and outputs a valid signal when it is determined to be lightly loaded; The dynamic logic processing module outputs a driving instruction signal according to the dynamic preparation signal and the effective signal; The dynamic driving module amplifies the driving instruction signal to generate the dynamic driving signal, and outputs the dynamic driving signal.

8. The secondary synchronous rectification method according to claim 7, characterized in that: The secondary synchronous rectification method further includes: The primary conduction detection module determines whether the primary switch tube in the switching power supply is turned on according to the drain voltage of the secondary switch tube, and outputs a dynamic termination instruction when it is determined that the primary switch tube is turned on; The dynamic logic processing module stops outputting the driving instruction signal when receiving the dynamic termination instruction.

9. The secondary synchronous rectification method according to claim 8, characterized in that: The dynamic logic processing module outputs a driving instruction signal according to the dynamic preparation signal and the effective signal, including: The dynamic logic processing module includes a dynamic pulse generating circuit and a dynamic pulse circulation circuit. The dynamic pulse generating circuit outputs the driving instruction signal when receiving the dynamic preparation signal and the valid signal at the same time, and stops outputting the driving instruction signal when receiving the dynamic termination instruction. The dynamic pulse cycle circuit outputs a dynamic cycle trigger signal when receiving the driving instruction signal, and stops outputting the dynamic cycle trigger signal when receiving the dynamic termination instruction; The dynamic pulse generating circuit outputs the driving instruction signal when receiving the dynamic cycle trigger signal.

10. The secondary synchronous rectification method according to claim 9, characterized in that: The secondary synchronous rectification method further includes: The dynamic overcurrent detection module detects the drain current of the dynamic trigger switch tube and sends a shutdown instruction to the dynamic pulse generating circuit when the drain current of the dynamic trigger switch tube is greater than a predetermined current threshold. Wherein, upon receiving the shutdown instruction issued by the dynamic overcurrent detection module, the dynamic pulse generating circuit stops outputting the driving instruction signal.

11. The secondary synchronous rectification method according to claim 10, characterized in that: The secondary synchronous rectification method also includes: When the dynamic pulse generating circuit outputs the driving instruction signal, a working instruction is sent to the dynamic overcurrent detection module so that the dynamic overcurrent detection module continues to work within a predetermined time length; and a shielding instruction is sent to the secondary driving circuit so that the secondary driving circuit does not output the secondary rectifier driving signal within the predetermined time length.

12. The secondary synchronous rectification method according to claim 7, wherein: The secondary drive circuit includes a switch sampling module, a drive logic processing module and a drive module. The secondary drive circuit outputs a secondary rectifier drive signal, including: The switch sampling module samples the drain current of the secondary switch tube; The driving logic processing module generates a normal driving signal according to the drain current of the secondary switch tube; If the normal driving signal is valid, the driving module amplifies the normal driving signal to generate the secondary rectifier driving signal and outputs the secondary rectifier driving signal. Wherein, the method further includes: when the normal driving signal sent by the driving logic processing module is valid, the dynamic logic processing module stops outputting the driving instruction signal.

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