Soft switching on-line monitoring device of synchronous Buck converter

Abstract

The embodiment of the invention discloses a soft switching on-line monitoring device of a synchronous Buck converter, which comprises a digital controller used for transmitting a master control signal to a master control switch tube and a trigger and transmitting a synchronous control signal to a synchronous rectifier tube, and a resistance voltage divider used for sampling the voltage of a switch node of the synchronous Buck converter, the switch node sampling circuit is used for sampling voltage of a switch node and transmitting the sampling voltage of the switch node to the high-speed comparator, the high-speed comparator is used for comparing the sampling voltage of the switch node with reference voltage and transmitting a comparison signal to the trigger, and the trigger is used for determining a level signal according to the comparison signal and a master control signal. The digital controller is used for determining the current on-off state of the synchronous Buck converter according to the level signal; the current switching state of the synchronous Buck converter can be fed back in real time, so that control parameters of the synchronous Buck converter can be adjusted in time, it is ensured that the synchronous Buck converter is always kept in a soft switching operation state, and switching loss and electromagnetic interference are effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and in particular to a soft switch online monitoring device for a synchronous Buck converter. Background Art

[0002] The synchronous Buck converter has significantly improved performance compared to the traditional asynchronous Buck converter. The key improvement is to replace the original diode with a controllable switch tube. This change directly leads to a lower on-state voltage drop, thereby significantly improving the efficiency of the converter. More importantly, the synchronous Buck converter also has the ability to flow energy in both directions, which enables it to flexibly serve as a bidirectional power transmission interface between the DC bus and the energy storage unit, providing higher flexibility and adaptability for the power system.

[0003] In the synchronous Buck converter, there are two working modes: soft switching state and hard switching state. The soft switching state means that when the main control switch tube is turned on or off, the voltage and current change relatively slowly, and no significant voltage or current spikes are generated. In this state, the switching loss is small and the electromagnetic interference is relatively low; the hard switching state means that when the main control switch tube is turned on or off, the voltage and current change more violently, and obvious voltage or current spikes will be generated. In this state, the switching loss is large and the electromagnetic interference is relatively high.

[0004] However, the synchronous Buck converter usually operates in a hard switching state, which causes a significant increase in the switching loss of the main control switch tube, which not only reduces the operating efficiency of the synchronous Buck converter, but also aggravates the electromagnetic interference problem.

[0005] Further research found that if the real-time switching state of the synchronous Buck converter can be detected, the control parameters of the synchronous Buck converter can be adjusted according to the detection results to ensure that it always maintains a soft switching operation state. However, current technology has not yet provided a soft switching online monitoring method for synchronous Buck converters. Summary of the invention

[0006] Based on this, it is necessary to propose a soft switching online monitoring device for a synchronous Buck converter to address the above problems, so that the current switching state of the synchronous Buck converter can be fed back in real time, so as to adjust the control parameters of the synchronous Buck converter in time to ensure that it always maintains a soft switching operation state, thereby effectively reducing switching losses and electromagnetic interference.

[0007] To achieve the above object, the present invention provides a soft switch online monitoring device for a synchronous Buck converter, the device comprising a digital controller, a resistor divider, a high-speed comparator and a trigger;

[0008] The digital controller is connected to the trigger, and the high-speed comparator is connected to the resistor divider and the trigger respectively;

[0009] The digital controller is used to be connected to the gate terminal of the main control switch tube and the gate terminal of the synchronous rectifier tube of the synchronous Buck converter respectively, and the resistor divider is used to be connected to the source terminal of the main control switch tube;

[0010] The digital controller is used to transmit the main control signal to the main control switch tube and the trigger, and transmit the synchronous control signal to the synchronous rectifier tube;

[0011] The resistor divider is used to sample the switch node voltage of the synchronous Buck converter to obtain a switch node sample voltage, and transmit the switch node sample voltage to the high-speed comparator;

[0012] The high-speed comparator is used to compare the switch node sampling voltage with a reference voltage to obtain a comparison signal, and transmit the comparison signal to the trigger;

[0013] The trigger is used to determine a level signal according to the comparison signal and the main control signal, and transmit the level signal to the digital controller;

[0014] The digital controller is used to determine the current switching state of the synchronous Buck converter according to the level signal.

[0015] Optionally, the PWM module of the digital controller is connected to the trigger, and the IO module of the digital controller is connected to the trigger;

[0016] The PWM module is used to be connected to the gate end of the main control switch tube and the gate end of the synchronous rectifier tube respectively;

[0017] The PWM module is used to generate the main control signal and the synchronous control signal, and transmit the main control signal to the main control switch tube and the trigger, and transmit the synchronous control signal to the synchronous rectifier tube;

[0018] The trigger is used to transmit the level signal to the IO module;

[0019] The control module of the digital controller is used to determine the current switch state according to the level signal.

[0020] Optionally, the DAC module of the digital controller is connected to the high-speed comparator;

[0021] The ADC module of the digital controller is used to connect to the DC power supply of the synchronous Buck converter;

[0022] The ADC module is used to sample the input voltage of the synchronous Buck converter to obtain an input sample voltage;

[0023] The control module is used to determine the reference voltage according to the input sampling voltage;

[0024] The DAC module is used to transmit the reference voltage to the high-speed comparator.

[0025] Optionally, the control module is used to determine the reference voltage according to the input sampled voltage and a sampled voltage division coefficient of the resistor voltage divider.

[0026] Optionally, the control module is used to adjust the main control signal and the synchronization control signal generated by the PWM module according to the current switch state.

[0027] Optionally, the CLK pin of the trigger is connected to the high-speed comparator, the D pin of the trigger is connected to the PWM module, and the Q pin of the trigger is connected to the IO module.

[0028] Optionally, the non-inverting input terminal of the high-speed comparator is connected to the resistor divider, the inverting input terminal of the high-speed comparator is connected to the DAC module, and the output terminal of the high-speed comparator is connected to the CLK pin of the trigger.

[0029] Optionally, the resistor divider includes a first resistor and a second resistor;

[0030] One end of the first resistor is connected to one end of the second resistor and then connected to the non-inverting input end of the high-speed comparator;

[0031] The other end of the first resistor is used to be connected to the source terminal of the main control switch tube, and the other end of the second resistor is grounded.

[0032] Optionally, in the case where the rising edge of the comparison signal precedes the rising edge of the main control signal, the level signal is a low level signal;

[0033] In the case that the rising edge of the comparison signal lags behind the rising edge of the main control signal, the level signal is a high level signal.

[0034] Optionally, when the level signal is a low level signal, the current switch state is a soft switch state;

[0035] When the level signal is a high level signal, the current switch state is a hard switch state.

[0036] The embodiment of the present invention has the following beneficial effects: the above-mentioned device includes a digital controller connected to a trigger, a high-speed comparator connected to a resistor divider and a trigger respectively, the digital controller is used to be connected to the gate end of the main control switch tube of the synchronous Buck converter and the gate end of the synchronous rectifier tube, the resistor divider is used to be connected to the source end of the main control switch tube, the digital controller is used to transmit the main control signal to the main control switch tube and the trigger, and transmit the synchronous control signal to the synchronous rectifier tube, the resistor divider is used to sample the switch node voltage of the synchronous Buck converter to obtain the switch node sampling voltage, and transmit the switch node sampling voltage to the high-speed comparator, and the high-speed comparator is used to compare the sampling voltage with the reference voltage. Compare to obtain a comparison signal, and transmit the comparison signal to a trigger, the trigger is used to determine a level signal according to the comparison signal and the main control signal, and transmit the level signal to a digital controller, the digital controller is used to determine the current switching state of the synchronous Buck converter according to the level signal; so that the current switching state of the synchronous Buck converter can be fed back in real time, and then it can be determined whether the synchronous Buck converter is in a soft switching state or a hard switching state, so as to timely adjust the control parameters of the synchronous Buck converter to ensure that it always maintains a soft switching operation state, so that not only can the switching loss and electromagnetic interference be effectively reduced, but also the overall performance and operation efficiency of the synchronous Buck converter can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] in:

[0039] Figure 1 A schematic diagram of a synchronous Buck converter in an embodiment of the present application;

[0040] Figure 2 A schematic diagram of a soft-switching online monitoring device for a synchronous Buck converter according to an embodiment of the present application;

[0041] Figure 3 Another schematic diagram of a soft-switching online monitoring device for a synchronous Buck converter in an embodiment of the present application. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] The synchronous Buck converter has significantly improved performance compared to the traditional asynchronous Buck converter. The key improvement is to replace the original diode with a controllable switch tube. This change directly leads to a lower on-state voltage drop, thereby significantly improving the efficiency of the converter. More importantly, the synchronous Buck converter also has the ability to flow energy in both directions, which enables it to flexibly serve as a bidirectional power transmission interface between the DC bus and the energy storage unit, providing higher flexibility and adaptability for the power system.

[0044] In the synchronous Buck converter, there are two working modes: soft switching state and hard switching state. The soft switching state means that when the main control switch tube is turned on or off, the voltage and current change relatively slowly, and no significant voltage or current spikes are generated. In this state, the switching loss is small and the electromagnetic interference is relatively low; the hard switching state means that when the main control switch tube is turned on or off, the voltage and current change more violently, and obvious voltage or current spikes will be generated. In this state, the switching loss is large and the electromagnetic interference is relatively high.

[0045] However, the synchronous Buck converter usually operates in a hard switching state, which causes a significant increase in the switching loss of the main control switch tube, which not only reduces the operating efficiency of the synchronous Buck converter, but also aggravates the electromagnetic interference problem.

[0046] Further research found that if the real-time switching state of the synchronous Buck converter can be detected, the control parameters of the synchronous Buck converter can be adjusted according to the detection results to ensure that it always maintains a soft switching operation state. However, current technology has not yet provided a soft switching online monitoring method for synchronous Buck converters.

[0047] In response to the above problems, the present application proposes a soft switching online monitoring device for a synchronous Buck converter, which can provide real-time feedback on the current switching state of the synchronous Buck converter, so as to timely adjust the control parameters of the synchronous Buck converter to ensure that it always maintains a soft switching operating state, thereby effectively reducing switching losses and electromagnetic interference. The specific implementation principle will be described in detail in the following embodiments.

[0048] In order to better explain the following embodiments, the present application first provides a circuit topology diagram of a synchronous Buck converter and briefly describes it. Figure 1 , is a schematic diagram of a synchronous Buck converter in an embodiment of the present application, wherein the synchronous Buck converter shown in the schematic diagram includes a DC power supply, an input filter capacitor C1, a main control switch tube S1, a synchronous rectifier tube S2, an inductor L, an output filter capacitor C2 and a load resistor R L .

[0049] Among them, one end of the DC power supply is connected to one end of the input filter capacitor C1 and the drain end of the main control switch tube S1, and the other end of the DC power supply is connected to the other end of the input filter capacitor C1, the source end of the synchronous rectifier tube S2, one end of the output filter capacitor C2, and the load resistor R L One end of the output filter capacitor C2 is connected to the load resistor R L The other end of each is connected to one end of the inductor L, and the other end of the inductor L is respectively connected to the source end of the main control switch tube S1 and the drain end of the synchronous rectifier tube S2.

[0050] In some embodiments, corresponding control signals may be input to the gate terminal of the main control switch tube S1 and the gate terminal of the synchronous rectifier tube S2 respectively, so that the synchronous Buck converter can operate stably.

[0051] in, Figure 1 The V g is the input voltage of the synchronous Buck converter, i L is the current of the inductor L, v sw is the switch node voltage of the synchronous Buck converter, V o is the output voltage of the synchronous Buck converter, c1 is the main control signal, and c2 is the synchronous control signal.

[0052] See also Figure 2 , is a schematic diagram of a soft switching online monitoring device for a synchronous Buck converter in an embodiment of the present application, the device comprising a digital controller 110, a resistor divider 120, a high-speed comparator 130 and a trigger 140.

[0053] Among them, the digital controller 110 is connected to the trigger 140, and the high-speed comparator 130 is connected to the resistor divider 120 and the trigger 140 respectively; the digital controller 110 is used to be connected to the gate end of the main control switch tube S1 and the gate end of the synchronous rectifier tube S2 of the synchronous Buck converter respectively, and the resistor divider 120 is used to be connected to the source end of the main control switch tube S1.

[0054] In a feasible implementation, the digital controller 110 is used to transmit the main control signal to the main control switch tube S1 and the trigger 140, and transmit the synchronous control signal to the synchronous rectifier tube S2; the resistor divider 120 is used to sample the switch node voltage of the synchronous Buck converter to obtain the switch node sampling voltage, and transmit the switch node sampling voltage to the high-speed comparator 130; the high-speed comparator 130 is used to compare the switch node sampling voltage with the reference voltage to obtain a comparison signal, and transmit the comparison signal to the trigger 140; the trigger 140 is used to determine the level signal according to the comparison signal and the main control signal, and transmit the level signal to the digital controller 110; the digital controller 110 is used to determine the current switching state of the synchronous Buck converter according to the level signal.

[0055] in, Figure 2 Q shown is a level signal. The main control signal and the synchronous control signal are used to control the switching actions of the main control switch tube S1 and the synchronous rectifier tube S2 respectively to ensure the stable operation of the synchronous Buck converter. The reference voltage can be obtained and pre-set by the operator based on a lot of experience, experiments or statistics; of course, it can also be set by the operator according to actual needs, which is not limited here.

[0056] In some embodiments, the reference voltage may be determined according to the input voltage of the synchronous Buck converter.

[0057] It should be noted that when the current switching state of the synchronous Buck converter is a soft switching state, since the switch node voltage of the synchronous Buck converter has increased from 0 to the input voltage of the synchronous Buck converter before the main control signal arrives, at this time, the rising edge of the comparison signal is ahead of the rising edge of the main control signal; when the current switching state of the synchronous Buck converter is a hard switching state, since the switch node voltage of the synchronous Buck converter only increases from 0 to the input voltage of the synchronous Buck converter after the main control signal arrives, at this time, the rising edge of the comparison signal lags behind the rising edge of the main control signal; therefore, in the present application, the current switching state of the synchronous Buck converter can be determined according to whether the rising edge of the comparison signal is ahead of the rising edge of the main control signal or lags behind the rising edge of the main control signal, that is, the current switching state of the synchronous Buck converter is determined according to the level signal.

[0058] In the embodiment of the present application, by reasonably setting up the device including the digital controller 110, the resistor divider 120, the high-speed comparator 130 and the trigger 140, the current switching state of the synchronous Buck converter can be fed back in real time, and then it can be determined whether the synchronous Buck converter is in a soft switching state or a hard switching state, so as to timely adjust the control parameters of the synchronous Buck converter to ensure that it always maintains a soft switching operating state. In this way, not only can the switching loss and electromagnetic interference be effectively reduced, but also the overall performance and operating efficiency of the synchronous Buck converter can be improved.

[0059] In addition, the method of the present application also has the following advantages: by detecting the switching state of the synchronous Buck converter in real time, it is possible to analyze the switching state change pattern to assist in identifying potential faults within the synchronous Buck converter, and to provide a basis for optimizing the control strategy and improving the reliability of the device.

[0060] based on Figure 2 , see Figure 3 , is another schematic diagram of a soft switching online monitoring device for a synchronous Buck converter in an embodiment of the present application, wherein the PWM module of the digital controller 110 is connected to the trigger 140, and the IO module of the digital controller 110 is connected to the trigger 140; the PWM module is used to be connected to the gate end of the main control switch tube S1 and the gate end of the synchronous rectifier tube S2 respectively.

[0061] In a feasible implementation, the PWM module is used to generate a main control signal and a synchronous control signal, and transmit the main control signal to the main control switch tube S1 and the trigger 140, and transmit the synchronous control signal to the synchronous rectifier tube S2; the trigger 140 is used to transmit the level signal to the IO module; the control module of the digital controller 110 is used to determine the current switch state according to the level signal.

[0062] in, Figure 3 The V ref is the reference voltage, the PWM module is the pulse width modulation module, and the IO module is the general input and output module.

[0063] In the embodiment of the present application, by integrating the PWM module and the IO module into the digital controller 110, the number of peripherals is reduced and the complexity of the device is reduced. The PWM module is responsible for generating a control signal, which is directly connected to the switch tube, and at the same time feeds back the switch status information to the IO module to achieve more precise control and status identification.

[0064] Please continue reading Figure 3 The DAC module of the digital controller 110 is connected to the high-speed comparator 130; the ADC module of the digital controller 110 is used to connect to the DC power supply of the synchronous Buck converter.

[0065] In a feasible implementation, the ADC module is used to sample the input voltage of the synchronous Buck converter to obtain an input sampling voltage; the control module is used to determine a reference voltage according to the input sampling voltage; and the DAC module is used to transmit the reference voltage to the high-speed comparator 130 .

[0066] Among them, the ADC module is an analog-to-digital conversion module, and the DAC module is a digital-to-analog conversion module.

[0067] In some embodiments, the ADC module is used to convert the analog input sampling voltage into a digital input sampling voltage to obtain the input sampling voltage during the process of sampling the input voltage of the synchronous Buck converter; the DAC module is used to convert the digital reference signal into an analog reference voltage during the process of transmitting the reference voltage to the high-speed comparator 130 to ensure that the high-speed comparator 130 can be recognized normally.

[0068] In the embodiment of the present application, by integrating the ADC module and the DAC module into the digital controller 110, the number of peripherals is reduced, the complexity of the circuit and the cost of the device are reduced, and the stability of the device is improved. The ADC module converts the analog input voltage into a digital signal through analog-to-digital conversion, and the control module dynamically adjusts the reference voltage according to the input voltage value, thereby achieving more accurate detection and control of the switching state. The DAC module converts the digital reference voltage into an analog voltage, which can ensure that the high-speed comparator 130 can work normally and accurately detect the switching state, thereby helping the synchronous Buck converter to always maintain a soft switching operation state and improve overall efficiency.

[0069] In a feasible implementation, the control module is used to determine the reference voltage according to the input sampled voltage and the sampled voltage division coefficient of the resistor voltage divider 120 .

[0070] Regarding the determination method of the reference voltage, in some embodiments, the product of the input sample voltage and the sample voltage division coefficient may be used as the reference voltage.

[0071] In the embodiment of the present application, by dynamically adjusting the reference voltage according to the input voltage and the resistor voltage division coefficient through the control module, the switch state can be identified more accurately and flexibly, thereby achieving more precise control of the synchronous Buck converter.

[0072] It is understandable that changes in the input voltage will cause changes in the reference voltage. Therefore, by dynamically adjusting the reference voltage, the switching state can be identified more accurately and flexibly, thereby achieving more refined control of the synchronous Buck converter.

[0073] In a feasible implementation, the control module is used to adjust the main control signal and the synchronous control signal generated by the PWM module according to the current switch state.

[0074] In the embodiment of the present application, by timely adjusting the control parameters of the synchronous Buck converter according to the current switching state of the synchronous Buck converter, it can be ensured that it always maintains a soft switching operation state, so as to effectively reduce switching losses and electromagnetic interference, and improve the overall performance and operating efficiency of the synchronous Buck converter.

[0075] Please continue reading Figure 3 , the CLK pin of the trigger 140 is connected to the high-speed comparator 130, the D pin of the trigger 140 is connected to the PWM module, and the Q pin of the trigger 140 is connected to the IO module.

[0076] The CLK pin is an input pin of the trigger 140 and also a clock pin, the D pin is another input pin of the trigger 140 , and the Q pin is an output pin of the trigger 140 .

[0077] In the embodiment of the present application, connecting the high-speed comparator 130 through the CLK pin of the trigger 140 can ensure that when the high-speed comparator 130 generates a comparison signal, the D pin is connected to the PWM module to adjust the output of the level signal according to the comparison signal and the main control signal, and the Q pin is connected to the IO module to output the level signal, and the switch state is fed back to the digital controller 110, thereby realizing accurate feedback and control of the state of the synchronous Buck converter.

[0078] In addition, this connection method closely combines the switch state detection with the control link, so that the device can adjust the control parameters according to the real-time status, thereby keeping the synchronous Buck converter in the soft switching operation state and improving efficiency and performance.

[0079] Please continue reading Figure 3 The non-inverting input terminal of the high-speed comparator 130 is connected to the resistor divider 120 , the inverting input terminal of the high-speed comparator 130 is connected to the DAC module, and the output terminal of the high-speed comparator 130 is connected to the CLK pin of the trigger 140 .

[0080] In the embodiment of the present application, the voltage signal generated by the resistor divider 120, which represents the real-time change of the switch node voltage, can be sent to the non-inverting input terminal of the high-speed comparator 130 by connecting the resistor divider 120 through the non-inverting input terminal of the high-speed comparator 130. The inverting input terminal is connected to the DAC module to introduce a reference voltage so that the high-speed comparator 130 can perform a comparison operation with the voltage collected by the resistor divider 120. The comparison result and the trigger result of the main control signal can be converted into a level signal by connecting the output terminal to the CLK pin of the trigger 140, and finally transmitted to the control module to realize the determination and feedback of the switch state.

[0081] In addition, this connection method realizes real-time judgment of the switch node voltage through the high-speed comparator 130, and converts the comparison result and the trigger result of the main control signal into a level signal through the trigger 140, thereby finally realizing accurate feedback and control of the switch state.

[0082] Please continue reading Figure 3 The resistor divider 120 includes a first resistor and a second resistor (not numbered in the figure).

[0083] In a feasible implementation, one end of the first resistor is connected to one end of the second resistor and then connected to the in-phase input end of the high-speed comparator 130; the other end of the first resistor is used to connect to the source end of the main control switch tube S1, and the other end of the second resistor is grounded.

[0084] In the embodiment of the present application, by connecting the other end of the first resistor to the source end of the main control switch tube S1, the switch node voltage can be collected and transmitted to the non-inverting input end of the high-speed comparator 130. By using the second resistor and grounding, the resistor divider 120 structure formed can reduce the switch node voltage to a voltage suitable for the working range of the high-speed comparator 130.

[0085] In addition, this connection method realizes the acquisition of the switch node voltage, and sends the acquired voltage signal to the high-speed comparator 130 for processing, thereby laying a foundation for detecting the switch state.

[0086] In a feasible implementation, when the rising edge of the comparison signal precedes the rising edge of the main control signal, the level signal is a low level signal; when the rising edge of the comparison signal lags behind the rising edge of the main control signal, the level signal is a high level signal.

[0087] In some embodiments, a low level signal is 0 and a high level signal is 1.

[0088] In the embodiment of the present application, the level state (high level or low level) of the level signal is determined by comparing the signal with the main control signal, so that the switching state of the synchronous Buck converter can be accurately determined.

[0089] In a feasible implementation, when the level signal is a low level signal, the current switch state is a soft switch state; when the level signal is a high level signal, the current switch state is a hard switch state.

[0090] In the embodiment of the present application, the current switch state of the synchronous Buck converter is determined by the level state (high level or low level) of the level signal, which can more accurately identify the state of the switch and thus achieve more precise control of the synchronous Buck converter.

[0091] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0092] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A soft switch online monitoring device for a synchronous Buck converter, characterized in that: The device includes a digital controller, a resistor divider, a high-speed comparator and a trigger; The digital controller is connected to the trigger, and the high-speed comparator is connected to the resistor divider and the trigger respectively; The digital controller is used to be connected to the gate terminal of the main control switch tube and the gate terminal of the synchronous rectifier tube of the synchronous Buck converter respectively, and the resistor divider is used to be connected to the source terminal of the main control switch tube; The digital controller is used to transmit the main control signal to the main control switch tube and the trigger, and transmit the synchronous control signal to the synchronous rectifier tube; The resistor divider is used to sample the switch node voltage of the synchronous Buck converter to obtain a switch node sample voltage, and transmit the switch node sample voltage to the high-speed comparator; The high-speed comparator is used to compare the switch node sampling voltage with a reference voltage to obtain a comparison signal, and transmit the comparison signal to the trigger; The trigger is used to determine a level signal according to the comparison signal and the main control signal, and transmit the level signal to the digital controller; The digital controller is used to determine the current switching state of the synchronous Buck converter according to the level signal.

2. The device according to claim 1, characterized in that The PWM module of the digital controller is connected to the trigger, and the IO module of the digital controller is connected to the trigger; The PWM module is used to be connected to the gate end of the main control switch tube and the gate end of the synchronous rectifier tube respectively; The PWM module is used to generate the main control signal and the synchronous control signal, and transmit the main control signal to the main control switch tube and the trigger, and transmit the synchronous control signal to the synchronous rectifier tube; The trigger is used to transmit the level signal to the IO module; The control module of the digital controller is used to determine the current switch state according to the level signal.

3. The device according to claim 2, characterized in that The DAC module of the digital controller is connected to the high-speed comparator; The ADC module of the digital controller is used to connect to the DC power supply of the synchronous Buck converter; The ADC module is used to sample the input voltage of the synchronous Buck converter to obtain an input sample voltage; The control module is used to determine the reference voltage according to the input sampling voltage; The DAC module is used to transmit the reference voltage to the high-speed comparator.

4. The device according to claim 3, characterized in that The control module is used to determine the reference voltage according to the input sampled voltage and a sampled voltage division coefficient of the resistor voltage divider.

5. The device according to claim 3, characterized in that The control module is used to adjust the main control signal and the synchronization control signal generated by the PWM module according to the current switch state.

6. The device according to claim 3, characterized in that The CLK pin of the trigger is connected to the high-speed comparator, the D pin of the trigger is connected to the PWM module, and the Q pin of the trigger is connected to the IO module.

7. The device according to claim 6, characterized in that The non-inverting input terminal of the high-speed comparator is connected to the resistor voltage divider, the inverting input terminal of the high-speed comparator is connected to the DAC module, and the output terminal of the high-speed comparator is connected to the CLK pin of the trigger.

8. The device according to claim 7, characterized in that The resistor divider includes a first resistor and a second resistor; One end of the first resistor is connected to one end of the second resistor and then connected to the non-inverting input end of the high-speed comparator; The other end of the first resistor is used to be connected to the source terminal of the main control switch tube, and the other end of the second resistor is grounded.

9. The device according to claim 1, characterized in that In the case where the rising edge of the comparison signal precedes the rising edge of the main control signal, the level signal is a low level signal; In the case that the rising edge of the comparison signal lags behind the rising edge of the main control signal, the level signal is a high level signal.

10. The device according to claim 1 or 9, characterized in that When the level signal is a low level signal, the current switch state is a soft switch state; When the level signal is a high level signal, the current switch state is a hard switch state.

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