A soft switching on-line monitoring device for synchronous buck converter

Abstract

This invention discloses an online monitoring device for soft switching of a synchronous Buck converter, comprising: a digital controller for transmitting a main control signal to a main control switch and a trigger, and a synchronous control signal to a synchronous rectifier; a resistor divider for sampling the switching node voltage of the synchronous Buck converter and transmitting the sampled switching node voltage to a high-speed comparator; the high-speed comparator for comparing the sampled switching node voltage with a reference voltage and transmitting the comparison signal to the trigger; the trigger for determining a level signal based on the comparison signal and the main control signal; and the digital controller for determining the current switching state of the synchronous Buck converter based on the level signal. This allows for real-time feedback of the current switching state of the synchronous Buck converter, enabling timely adjustment of its control parameters to ensure it remains in a soft-switching operating state, thereby effectively reducing switching losses and electromagnetic interference.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and in particular to an online monitoring device for soft switching of a synchronous Buck converter. Background Technology

[0002] Compared to traditional asynchronous Buck converters, synchronous Buck converters offer significant performance improvements. The key improvement lies in replacing the original diodes with controllable switching transistors, a change that directly results in a lower on-state voltage drop, thus significantly improving converter efficiency. More importantly, synchronous Buck converters also possess bidirectional energy flow capabilities, enabling them to flexibly serve as a bidirectional power transfer interface between the DC bus and energy storage units, providing greater flexibility and adaptability to power systems.

[0003] Synchronous Buck converters operate in two modes: soft-switching and hard-switching. Soft-switching refers to a state where the voltage and current changes smoothly when the main control switch is turned on or off, without significant voltage or current spikes. In this mode, switching losses are low, and electromagnetic interference is relatively low. Hard-switching, on the other hand, refers to a state where the voltage and current changes drastically when the main control switch is turned on or off, producing noticeable voltage or current spikes. In this mode, switching losses are high, and electromagnetic interference is relatively high.

[0004] However, synchronous Buck converters typically operate in hard-switching mode, which significantly increases the switching losses of the main control switch. This not only reduces the operating efficiency of the synchronous Buck converter but also exacerbates electromagnetic interference problems.

[0005] Further research revealed 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 based on the detection results to ensure that it always maintains a soft-switching operation. However, current technology does not provide an online monitoring method for the soft-switching of synchronous Buck converters. Summary of the Invention

[0006] Based on this, it is necessary to propose an online monitoring device for soft switching of synchronous Buck converters to address the above problems. This device can provide real-time feedback on the current switching state of the synchronous Buck converter, enabling timely adjustment of the control parameters of the synchronous Buck converter and ensuring that it always maintains a soft-switching operating state, thereby effectively reducing switching losses and electromagnetic interference.

[0007] To achieve the above objectives, the present invention provides a soft-switching 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 connect to the gate terminal of the main control switch of the synchronous Buck converter and the gate terminal of the synchronous rectifier, respectively, and the resistor divider is used to connect to the source terminal of the main control switch.

[0010] The digital controller is used to transmit the main control signal to the main control switch and the trigger, and to transmit the synchronization control signal to the synchronization rectifier.

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

[0012] The high-speed comparator is used to compare the sampled voltage of the switching node with the 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 based on the comparison signal and the main control signal, and to 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 based on 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 connect to the gate terminal of the main control switch and the gate terminal of the synchronous rectifier, respectively.

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

[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 based on 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 the input sample voltage;

[0023] The control module is used to determine the reference voltage based on the input sampled 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 based on the input sampled voltage and the sampling voltage division coefficient of the resistor 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 switching state.

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

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

[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 of the high-speed comparator.

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

[0032] Optionally, if the rising edge of the comparison signal leads the rising edge of the master control signal, the level signal is a low level signal.

[0033] When the rising edge of the comparison signal lags behind the rising edge of the master 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 present invention provides the following advantages: The device comprises a digital controller connected to a flip-flop, a high-speed comparator connected to a resistor divider and the flip-flop, a digital controller connected to the gate of the main control switch of the synchronous Buck converter and the gate of the synchronous rectifier, a resistor divider connected to the source terminal of the main control switch, a digital controller transmitting the main control signal to the main control switch and the flip-flop, and transmitting the synchronous control signal to the synchronous rectifier, and a resistor divider sampling the switching node voltage of the synchronous Buck converter to obtain a sampling voltage, transmitting the sampling voltage to the high-speed comparator, and the high-speed comparator comparing the sampling voltage with a reference voltage. The comparison signal is obtained and transmitted to the flip-flop. The flip-flop determines the level signal based on the comparison signal and the main control signal, and transmits the level signal to the digital controller. The digital controller determines the current switching state of the synchronous Buck converter based on the level signal. This allows for real-time feedback of the current switching state of the synchronous Buck converter, thereby determining whether the synchronous Buck converter is in a soft-switching or hard-switching state. This enables timely adjustment of the control parameters of the synchronous Buck converter, ensuring that it always maintains a soft-switching operation. In this way, switching losses and electromagnetic interference can be effectively reduced, and the overall performance and operating efficiency of the synchronous Buck converter can be improved. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] in:

[0039] Figure 1 This is a schematic diagram of the synchronous Buck converter in the embodiments of this application;

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

[0041] Figure 3 This is another schematic diagram of a soft-switching online monitoring device for a synchronous Buck converter according to an embodiment of this application. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Compared to traditional asynchronous Buck converters, synchronous Buck converters offer significant performance improvements. The key improvement lies in replacing the original diodes with controllable switching transistors, a change that directly results in a lower on-state voltage drop, thus significantly improving converter efficiency. More importantly, synchronous Buck converters also possess bidirectional energy flow capabilities, enabling them to flexibly serve as a bidirectional power transfer interface between the DC bus and energy storage units, providing greater flexibility and adaptability to power systems.

[0044] Synchronous Buck converters operate in two modes: soft-switching and hard-switching. Soft-switching refers to a state where the voltage and current changes smoothly when the main control switch is turned on or off, without significant voltage or current spikes. In this mode, switching losses are low, and electromagnetic interference is relatively low. Hard-switching, on the other hand, refers to a state where the voltage and current changes drastically when the main control switch is turned on or off, producing noticeable voltage or current spikes. In this mode, switching losses are high, and electromagnetic interference is relatively high.

[0045] However, synchronous Buck converters typically operate in hard-switching mode, which significantly increases the switching losses of the main control switch. This not only reduces the operating efficiency of the synchronous Buck converter but also exacerbates electromagnetic interference problems.

[0046] Further research revealed 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 based on the detection results to ensure that it always maintains a soft-switching operation. However, current technology does not provide an online monitoring method for the soft-switching of synchronous Buck converters.

[0047] To address the aforementioned issues, this application proposes a soft-switching online monitoring device for a synchronous Buck converter. This device enables real-time feedback of the current switching state of the synchronous Buck converter, allowing for timely adjustment of the converter's control parameters to ensure it remains in a soft-switching operating state. This effectively reduces switching losses and electromagnetic interference. The specific implementation principle will be described in detail in the following embodiments.

[0048] To better explain the following embodiments, this application first provides a circuit topology diagram of a synchronous Buck converter and a brief description. Please refer to... Figure 1 This is a schematic diagram of a synchronous Buck converter in an embodiment of this application. The synchronous Buck converter shown in the diagram includes a DC power supply, an input filter capacitor C1, a main control switch S1, a synchronous rectifier S2, an inductor L, an output filter capacitor C2, and a load resistor R. L .

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

[0050] In some embodiments, the synchronous Buck converter can be made to operate stably by inputting corresponding control signals to the gate terminals of the main control switch S1 and the synchronous rectifier S2, respectively.

[0051] in, Figure 1 V shown g i is the input voltage of the synchronous Buck converter. L Let v be the current in inductor L. sw V is the switching node voltage of the synchronous Buck converter. o C1 is the output voltage of the synchronous Buck converter, C2 is the main control signal, and C2 is the synchronization control signal.

[0052] Please see Figure 2 This is a schematic diagram of a soft-switching online monitoring device for a synchronous Buck converter according to an embodiment of this application. The device includes a digital controller 110, a resistor divider 120, a high-speed comparator 130, and a trigger 140.

[0053] The digital controller 110 is connected to the flip-flop 140, and the high-speed comparator 130 is connected to the resistor divider 120 and the flip-flop 140 respectively. The digital controller 110 is used to connect to the gate terminal of the main control switch S1 of the synchronous Buck converter and the gate terminal of the synchronous rectifier S2 respectively. The resistor divider 120 is used to connect to the source terminal of the main control switch S1.

[0054] In one feasible implementation, the digital controller 110 transmits the main control signal to the main control switch S1 and the trigger 140, and transmits the synchronization control signal to the synchronous rectifier S2; the resistor divider 120 samples the switching node voltage of the synchronous Buck converter to obtain the switching node sample voltage, and transmits the switching node sample voltage to the high-speed comparator 130; the high-speed comparator 130 compares the switching node sample voltage with the reference voltage to obtain a comparison signal, and transmits the comparison signal to the trigger 140; the trigger 140 determines the level signal based on the comparison signal and the main control signal, and transmits the level signal to the digital controller 110; the digital controller 110 determines the current switching state of the synchronous Buck converter based on the level signal.

[0055] in, Figure 2 Q is shown as a level signal. The main control signal and the synchronous control signal are used to control the switching action of the main control switch S1 and the synchronous rectifier S2, respectively, to ensure the stable operation of the synchronous Buck converter. The reference voltage can be obtained and preset 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 can be determined based on 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 soft-switching, the switching node voltage of the synchronous Buck converter has already risen from 0 to the input voltage of the synchronous Buck converter before the arrival of the master control signal. In this case, the rising edge of the comparator signal leads the rising edge of the master control signal. When the current switching state of the synchronous Buck converter is hard-switching, the switching node voltage of the synchronous Buck converter rises from 0 to the input voltage of the synchronous Buck converter only after the arrival of the master control signal. In this case, the rising edge of the comparator signal lags behind the rising edge of the master control signal. Therefore, in this application, the current switching state of the synchronous Buck converter can be determined based on whether the rising edge of the comparator signal leads or lags behind the rising edge of the master control signal, that is, the current switching state of the synchronous Buck converter can be determined based on the level signal.

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

[0059] Furthermore, the method described in this application 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 patterns to help identify potential faults within the synchronous Buck converter, and to provide a basis for optimizing control strategies and improving the reliability of the device.

[0060] based on Figure 2 Please see Figure 3 This is another schematic diagram of a soft-switching online monitoring device for a synchronous Buck converter in an embodiment of this application. The PWM module of the digital controller 110 is connected to the flip-flop 140, and the IO module of the digital controller 110 is connected to the flip-flop 140. The PWM module is used to connect to the gate terminal of the main control switch S1 and the gate terminal of the synchronous rectifier S2, respectively.

[0061] In one feasible implementation, the PWM module is used to generate the main control signal and the synchronization control signal, and transmits the main control signal to the main control switch S1 and the trigger 140, and transmits the synchronization control signal to the synchronous rectifier 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 switching state based on the level signal.

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

[0063] In this embodiment, 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 lowered. The PWM module is responsible for generating control signals and is directly connected to the switching transistor. At the same time, it feeds back the switching status information to the IO module, thereby achieving more precise control and status recognition.

[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 one feasible implementation, the ADC module is used to sample the input voltage of the synchronous Buck converter to obtain the input sample voltage; the control module is used to determine the reference voltage based on the input sample voltage; and the DAC module is used to transmit the reference voltage to the high-speed comparator 130.

[0066] The ADC module is an analog-to-digital converter, and the DAC module is a digital-to-analog converter.

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

[0068] In this embodiment, by integrating the ADC module and 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 lowered, 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 operating state and improve overall efficiency.

[0069] In one feasible implementation, the control module is used to determine the reference voltage based on the input sampled voltage and the sampling voltage division coefficient of the resistive voltage divider 120.

[0070] Regarding the method of determining the reference voltage, in some embodiments, the product between the input sampling voltage and the sampling voltage division coefficient can be used as the reference voltage.

[0071] In this embodiment, by dynamically adjusting the reference voltage based on the input voltage and the voltage division coefficient of the resistor, the switching state can be identified more accurately and flexibly, thereby achieving more precise control over the synchronous Buck converter.

[0072] It is understandable that changes in the input voltage will lead to 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 precise control over the synchronous Buck converter.

[0073] In one feasible implementation, the control module is used to adjust the master control signal and synchronization control signal generated by the PWM module according to the current switching state.

[0074] In this embodiment, by adjusting the control parameters of the synchronous Buck converter in a timely manner according to the current switching state of the synchronous Buck converter, it can be ensured that the converter always maintains a soft-switching operation state, thereby effectively reducing switching losses and electromagnetic interference, and improving the overall performance and operating efficiency of the synchronous Buck converter.

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

[0076] Among them, the CLK pin is one input pin of the flip-flop 140, which is also the clock pin; the D pin is the other input pin of the flip-flop 140; and the Q pin is the output pin of the flip-flop 140.

[0077] In this embodiment, connecting the high-speed comparator 130 to the CLK pin of the flip-flop 140 ensures that when the high-speed comparator 130 generates a comparison signal, the D pin is connected to the PWM module to adjust the output level signal according to the comparison signal and the main control signal, and the Q pin is connected to the IO module to output a level signal, feeding back the switch state to the digital controller 110, thereby achieving accurate feedback and control of the synchronous Buck converter state.

[0078] Furthermore, this connection method tightly integrates switch status detection with the control loop, enabling the device to adjust control parameters based on real-time status, thereby maintaining the synchronous Buck converter in soft-switching operation and improving efficiency and performance.

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

[0080] In this embodiment, the voltage signal generated by the resistor divider 120, representing the real-time change of the switching node voltage, is sent to the non-inverting input of the high-speed comparator 130 via the non-inverting input of the high-speed comparator 130. The inverting input is connected to the DAC module to introduce a reference voltage, so that the high-speed comparator 130 can compare the voltage with that collected by the resistor divider 120. The comparison result and the trigger result of the main control signal are converted into a level signal by connecting the output to the CLK pin of the trigger 140, and finally transmitted to the control module to realize the determination and feedback of the switching state.

[0081] In addition, this connection method uses a high-speed comparator 130 to make real-time judgments on the voltage of the switching node, and uses a trigger 140 to convert the comparison result and the trigger result of the main control signal into a level signal, ultimately achieving accurate feedback and control of the switching state.

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

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

[0084] In this embodiment, by connecting the other end of the first resistor to the source terminal of the main control switch S1, the switching node voltage can be acquired and transmitted to the non-inverting input of the high-speed comparator 130. By using the second resistor and ground, the resistor divider 120 structure can reduce the switching node voltage to a voltage suitable for the operating range of the high-speed comparator 130.

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

[0086] In one feasible implementation, the level signal is a low-level signal when the rising edge of the comparison signal leads the rising edge of the master control signal; and a high-level signal when the rising edge of the comparison signal lags behind the rising edge of the master control signal.

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

[0088] In this embodiment, by comparing the signal and the master control signal, the level state (high level or low level) of the level signal can be determined, thereby enabling accurate determination of the switching state of the synchronous Buck converter.

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

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

[0091] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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 embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A soft switching on-line 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 connect to the gate terminal of the main control switch of the synchronous Buck converter and the gate terminal of the synchronous rectifier, respectively, and the resistor divider is used to connect to the source terminal of the main control switch. The digital controller is used to transmit the main control signal to the main control switch and the trigger, and to transmit the synchronization control signal to the synchronization rectifier. The resistor divider is used to sample the switching node voltage of the synchronous Buck converter to obtain the switching node sample voltage, and transmit the switching node sample voltage to the high-speed comparator; The high-speed comparator is used to compare the sampled voltage of the switching node with the reference voltage to obtain a comparison signal, and transmit the comparison signal to the trigger. The trigger is used to determine a level signal based on the comparison signal and the main control signal, and to transmit the level signal to the digital controller; The digital controller is used to determine the current switching state of the synchronous Buck converter based on the level signal; Wherein, if the rising edge of the comparison signal leads the rising edge of the master control signal, the current switching state is a soft switching state. When the rising edge of the comparison signal lags behind the rising edge of the master control signal, the current switching state is a hard switching state. The reference voltage is not equal to 0.

2. The apparatus 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 connect to the gate terminal of the main control switch and the gate terminal of the synchronous rectifier, respectively. The PWM module is used to generate the main control signal and the synchronization control signal, and transmit the main control signal to the main control switch and the trigger, and transmit the synchronization control signal to the synchronization rectifier. 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 based on the level signal.

3. The apparatus 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 the input sample voltage; The control module is used to determine the reference voltage based on the input sampled voltage; The DAC module is used to transmit the reference voltage to the high-speed comparator.

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

5. The apparatus 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 switching state.

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

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

8. The apparatus 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 of the high-speed comparator. The other end of the first resistor is used to connect to the source terminal of the main control switch, and the other end of the second resistor is grounded.

9. The apparatus according to claim 1, characterized in that, When the rising edge of the comparison signal leads the rising edge of the master 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 master control signal, the level signal is a high level signal.

10. The apparatus 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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