A step-down circuit, backup power module, server, step-down charging method and device

Abstract

The present invention discloses a step-down circuit, a backup power module, a server, a step-down charging method and a device. It relates to the field of power supply technology. A bootstrap boost circuit is combined with a first switch tube. When the power supply voltage of the server mainboard is loaded to the second end of the first switch tube, since the voltage of the bootstrap voltage output end of the current bootstrap boost circuit is 0V, the first switch tube is disconnected. At this time, the first switch tube is used to prevent backflow. On the basis of the first switch tube preventing backflow to the first capacitor from overcurrent, a bootstrap boost circuit is added. At the second moment of hot plugging, the level signal given by the output end of the control module and the bootstrap technology are used to increase the output voltage of the circuit, and the output bootstrap voltage is used as the driving voltage of the first switch tube to drive and control the conduction of the first switch tube. The driveability of the output voltage is improved, and the conduction of the first switch tube is driven by a sufficiently high driving voltage, while also improving the maintenance operability of the backup power module.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply, and in particular to a step-down circuit, a backup power module, a server, a step-down charging method and a device. Background Art

[0002] The backup power module of the storage server provides continuous power supply to the storage system when the mains power is lost or the power supply unit fails, ensuring the integrity and completeness of the data.

[0003] When the backup power module is connected to the mainboard of the whole machine, since the output voltage of the backup power module is 0V, the voltage of the mainboard of the whole machine will instantly charge the filter capacitor of the backup power module to generate a large impact current, causing overcurrent in the backup power module. If the switch tube is directly used to prevent backflow connection, the output voltage at this time drives the switch tube poorly, making the maintenance and operation of the backup power module poor.

[0004] Therefore, how to avoid overcurrent in the backup power module and poor output voltage driving is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0005] The object of the present invention is to provide a step-down circuit, a backup power module, a server, a step-down charging method and a device to solve the problems of overcurrent and poor output voltage drive of the backup power module.

[0006] In order to solve the above technical problems, the present invention provides a step-down circuit, which includes a control module, a bootstrap boost circuit, a first capacitor and a first switch tube;

[0007] The output end of the control module is connected to the input end of the bootstrap boost circuit; and is used to control the bootstrap boost circuit to output a bootstrap voltage;

[0008] The first output end of the bootstrap boost circuit is connected to the first end of the first capacitor and the first end of the first switch tube; the second end of the first capacitor is grounded;

[0009] The second output end of the bootstrap boost circuit serves as a bootstrap voltage output end and is connected to the control end of the first switch tube; the second end of the first switch tube is connected to the server mainboard;

[0010] The bootstrap boost circuit is used to drive the first switch tube to turn off when the bootstrap voltage output at the first moment of hot plugging is 0V; and to drive the first switch tube to turn on when the bootstrap voltage output under the level signal of the output end of the control module at the second moment of hot plugging.

[0011] In one aspect, the bootstrap boost circuit comprises a transformer, a first diode and a second capacitor; the transformer comprises a first winding and a second winding;

[0012] The same-name end of the first winding serves as the input end of the bootstrap boost circuit and is connected to the control end of the buck circuit;

[0013] The opposite-name end of the first winding serves as the first output end of the bootstrap boost circuit and is connected to the first end of the first capacitor, the same-name end of the second winding and the first end of the first switch tube;

[0014] The opposite-name end of the second winding is connected to the anode of the first diode; the cathode of the first diode is connected to the first end of the second capacitor and is connected to the control end of the first switch tube;

[0015] The common end of the first diode and the second capacitor serves as the second output end of the bootstrap voltage boost circuit; the second end of the second capacitor is grounded.

[0016] On the other hand, the process of determining the coil turns ratio of the first winding and the second winding includes:

[0017] Obtaining a threshold voltage and a critical voltage of the first switch tube;

[0018] Determining a driving voltage range of the first switch tube according to the threshold voltage and the critical voltage;

[0019] Determining a bootstrap voltage range of the bootstrap boost circuit according to the driving voltage range;

[0020] The coil turns ratio is determined according to the bootstrap voltage range of the bootstrap voltage boost circuit.

[0021] On the other hand, the coil turns ratio of the first winding and the second winding is 1:1.

[0022] On the other hand, the transformer of the bootstrap boost circuit and the first capacitor form a first filter circuit.

[0023] On the other hand, it also includes a second filtering circuit;

[0024] The first end of the second filter circuit is connected to the bootstrap voltage output end of the bootstrap boost circuit;

[0025] The second end of the second filter circuit is connected to the control end of the first switch tube.

[0026] On the other hand, the second filtering circuit includes a first resistor and a third capacitor;

[0027] The first end of the first resistor is connected to the bootstrap voltage output end of the bootstrap boost circuit;

[0028] The second end of the first resistor is connected to the control end of the first switch tube and is connected to the first end of the third capacitor;

[0029] A second terminal of the third capacitor is grounded.

[0030] On the other hand, the second filtering circuit further includes a second diode;

[0031] An anode of the second diode is connected to the second end of the first resistor and the first end of the third capacitor;

[0032] The cathode of the second diode is connected to the control end of the first switch tube.

[0033] On the other hand, the control module includes a control unit, a second switch tube and a third switch tube;

[0034] The control unit is connected to the control end of the second switch tube and the control end of the third switch tube; the second end of the second switch tube is connected to the first end of the third switch tube and serves as the output end of the control module;

[0035] The positive electrode of the power supply is connected to the first end of the second switch tube; the negative electrode of the power supply is connected to the second end of the third switch tube and is grounded.

[0036] In order to solve the above technical problems, the present invention also provides a backup power module, including the above-mentioned step-down circuit.

[0037] In order to solve the above technical problem, the present invention further provides a server, comprising a server mainboard and the above-mentioned backup power module; the output end of the backup power module is connected to the server mainboard.

[0038] In order to solve the above technical problems, the present invention also provides a buck charging method, which is applied to a buck circuit, wherein the buck circuit includes a control module, a bootstrap boost circuit, a first capacitor and a first switch tube; the output end of the control module is connected to the input end of the bootstrap boost circuit; the first output end of the bootstrap boost circuit is connected to the first end of the first capacitor and the first end of the first switch tube; the second end of the first capacitor is grounded; the second output end of the bootstrap boost circuit serves as a bootstrap voltage output end and is connected to the control end of the first switch tube; the second end of the first switch tube is connected to a server mainboard; the method includes:

[0039] When the output end of the control module is connected to the input end of the bootstrap boost circuit at the first moment of hot plugging, the bootstrap voltage of the bootstrap voltage output end of the bootstrap boost circuit is controlled to be 0V, so as to drive the first switch tube to be turned off;

[0040] When the output end of the control module outputs a level signal at the second moment of hot plugging, the bootstrap voltage output end of the bootstrap boost circuit is controlled to output a bootstrap voltage so as to drive the first switch tube to turn on.

[0041] In order to solve the above technical problems, the present invention further provides a step-down charging device, comprising:

[0042] Memory for storing computer programs;

[0043] A processor is used to implement the steps of the voltage reduction charging method when executing the computer program.

[0044] In order to solve the above technical problems, the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the step-down charging method are implemented.

[0045] In order to solve the above technical problem, the present invention also provides a computer program product, including a computer program / instruction, which implements the steps of the step-down charging method when executed by a processor.

[0046] The present invention provides a step-down circuit, which includes a control module, a bootstrap boost circuit, a first capacitor and a first switch tube; the output end of the control module is connected to the input end of the bootstrap boost circuit; and is used to control the bootstrap boost circuit to output a bootstrap voltage during hot plugging; the first output end of the bootstrap boost circuit is connected to the first end of the first capacitor and to the first end of the first switch tube; the second end of the first capacitor is grounded; the second output end of the bootstrap boost circuit serves as a bootstrap voltage output end and is connected to the control end of the first switch tube; and the second end of the first switch tube is connected to a server mainboard.

[0047] The beneficial effect of the present invention lies in that a bootstrap boost circuit is combined with a first switch tube. When the power supply voltage of the server mainboard is loaded to the second end of the first switch tube, since the voltage of the bootstrap voltage output end of the current bootstrap boost circuit is 0V, the first switch tube is disconnected, and the first switch tube is used to prevent backflow at this time. On the basis of the first switch tube preventing backflow to the first capacitor from overcurrent, a bootstrap boost circuit is added. At the second moment of hot plugging, the level signal given by the output end of the control module and the bootstrap technology are used to increase the output voltage of the circuit, that is, the level signal given to the bootstrap boost circuit by the output end of the control module, so as to output the bootstrap voltage as the driving voltage of the first switch tube, and drive and control the conduction of the first switch tube. In the case of preventing the overcurrent of the impact current caused by hot plugging, the conduction of the first switch tube is driven by a sufficiently high driving voltage, thereby improving the driveability of the output voltage and also improving the maintenance operability of the backup power module.

[0048] Secondly, the bootstrap boost circuit formed by the transformer increases the voltage and generates a voltage higher than the power supply voltage, which corresponds to the control end of the first switch tube, and generates a greater driveability. The voltage can be increased without increasing the current, reducing power loss. In addition, the transformer can provide electrical isolation to improve safety. In the process of determining the coil turns ratio, since the bootstrap voltage drives the control end of the first switch tube, it is necessary to determine the voltage value corresponding to the first output end of the bootstrap boost circuit and the bootstrap voltage output end by the coil turns ratio, and then drive the first switch tube to turn on and off, so as to ensure the diversity and flexibility of the driving range of the first switch tube. The first filter circuit is formed by the transformer and the first capacitor to smooth the pulse voltage generated by the switching action, reduce the ripple of the output voltage, prevent the output voltage fluctuation caused by load changes or input voltage fluctuations, and improve the transient load response performance. The setting of the second filter circuit realizes the setting of the soft switch, that is, when the switch tube is turned on, it is not a sudden change, which helps to reduce the electromagnetic interference of the switch and improve efficiency. At the same time, the voltage drop of the first switch tube when it is turned on is reduced, and the efficiency of the entire circuit is improved. The second filter circuit, which is composed of a combination of resistors and capacitors, can remove high-frequency noise while smoothing the pulses generated by the switching action, reducing the ripple and fluctuation of the output voltage. In addition, it is used to stabilize the voltage and counteract short-term fluctuations in the input voltage through the charging and discharging process of the capacitor. The connection relationship between the control unit in the control module and the second switch tube and the third switch tube is controlled by the control signal given to the second switch tube and the third switch tube by the control unit, so as to realize the alternating conduction of the second switch tube and the third switch tube, so as to control the output of the bootstrap voltage of the bootstrap boost circuit, reduce energy consumption, and improve conduction efficiency.

[0049] In addition, the present invention also provides a backup power module, a server, a step-down charging method, a device, a medium, and a product, which have the same beneficial effects as the above-mentioned step-down circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. 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.

[0051] Figure 1 Schematic diagram of the circuit for powering the traditional backup power module and the server motherboard;

[0052] Figure 2 A schematic diagram of the structure of a voltage-reducing circuit provided by an embodiment of the present invention;

[0053] Figure 3 A structural diagram of a server provided in an embodiment of the present invention;

[0054] Figure 4 A flowchart of a voltage reduction charging method provided by an embodiment of the present invention;

[0055] Figure 5 A voltage timing diagram of a backup power module in a hot-swap scenario provided by an embodiment of the present invention;

[0056] Figure 6 A structural diagram of a step-down charging device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0057] 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.

[0058] The core of the present invention is to provide a step-down circuit, a backup power module, a server, a step-down charging method and a device to solve the problems of overcurrent and poor output voltage drive of the backup power module.

[0059] In order to enable those skilled in the art to better understand the solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0060] In the storage server, the backup power module temporarily powers the system when the alternating current (AC) 220V power is lost, and writes the cache to the hard disk to ensure that the system data will not be lost. Since the backup power module needs to be maintained separately, it is required to be plugged in and out under power so that the damaged backup power module can be replaced. The output voltage of the backup power module composed of multiple cells is relatively high, and the operating voltage of the server system is 12V, so the backup power module needs to perform a step-down circuit (buck circuit) conversion before powering the system.

[0061] Figure 1 A schematic diagram of a circuit for supplying power to a traditional backup power module and a server motherboard, such as Figure 1As shown, the output Vout end of the buck circuit in the backup power module 1 is connected to the combined voltage (P12V_AUX) of the power supply unit (Power Supply Unit, PSU) and the backup power module 1 through the power connector J1 of the backup power module 1 and the power connector J2 of the server mainboard 2. Regarding the combined voltage, as long as one of the two is working, it can be ensured that the system will not lose power. The output end of the Buck circuit needs to be filtered by a large-capacity capacitor. When the backup power module 1 is unplugged from the whole machine for maintenance, the circuit does not work, and the voltage of the output filter capacitor of its buck circuit is 0. After the maintenance is completed, when the whole machine is inserted, the combined voltage (P12V_AUX) corresponding to the server mainboard 2 is instantaneously given to the filter capacitor Cout, and a large impact current is generated during charging, which will cause the combined voltage (P12V_AUX) to drop, or even overcurrent. The step-down circuit provided by the present invention can solve the above-mentioned technical problems corresponding to the hot plug of the backup power module.

[0062] Figure 2 A schematic diagram of a step-down circuit according to an embodiment of the present invention is shown in FIG. Figure 2 As shown, the buck circuit includes a control module 6, a bootstrap boost circuit 3, a first capacitor C1 and a first switch tube Q1;

[0063] The output end of the control module 6 is connected to the input end of the bootstrap boost circuit 3; and is used to control the bootstrap boost circuit 3 to output a bootstrap voltage;

[0064] The first output end of the bootstrap boost circuit 3 is connected to the first end of the first capacitor C1 and the first end of the first switch tube Q1; the second end of the first capacitor C1 is grounded;

[0065] The second output end of the bootstrap boost circuit 3 is used as a bootstrap voltage output end and is connected to the control end of the first switch tube Q1; the second end of the first switch tube Q1 is connected to the server mainboard 2;

[0066] The bootstrap boost circuit 3 is used to drive the first switch tube Q1 to turn off when the bootstrap voltage outputted at the first moment of hot plugging is 0V; and to drive the first switch tube Q1 to turn on when the bootstrap voltage outputted at the level signal of the output end of the control module 6 at the second moment of hot plugging.

[0067] It can be understood that the output end of the control module is used to control the output of the bootstrap boost circuit. The specific voltage value of the bootstrap voltage here can be related to the high and low levels output by the output end of the control module and the time at which it is output. For example, when the control end is connected to the input end of the bootstrap boost circuit, the output voltage of the buck circuit is 0V at this time. At the moment when the buck circuit is connected to the server motherboard, the corresponding power supply voltage of the server motherboard is 12V. In order to prevent backflow, the shutdown characteristics of the first switch tube are used to prevent overcurrent. The shutdown operation of the first switch tube is to drive the control end of the first switch tube to shut down. If the level signal output by the output end of the control module, in the actual process, the corresponding output bootstrap voltage exceeds the first output end of the bootstrap boost circuit, the control end of the first switch tube drives the first switch tube to turn on. Combined with the power supply voltage of the server motherboard, when the voltage of the first output end of the bootstrap boost circuit reaches the power supply voltage of the server motherboard, its corresponding bootstrap voltage is greater than the voltage of the first output end of the bootstrap boost circuit, and the first switch tube is turned on at this time.

[0068] In this embodiment, the process of realizing high and low level signals corresponding to the signal outputted from the output end of the control module is not limited. It can be based on the action of the switch tube device, or the high and low level signals can be executed by the control device trigger pulse signal, which can be set according to the actual situation. Regarding the signal outputted from the output end of the control module in this embodiment, its function is to control the bootstrap boost circuit to work and output the bootstrap voltage through the output of the signal.

[0069] The bootstrap boost circuit relies on the charging of the bootstrap capacitor to achieve the increase of the driving potential in a way that is equivalent to a battery. It is suitable for occasions where the high-side and low-side switches are alternately turned on. Figure 2 From the perspective of the bootstrap boost circuit, the first input terminal is terminal (1), the first output terminal is terminal (2), and the second output terminal is terminal (3). The first output terminal of the bootstrap boost circuit is connected to the first terminal of the first capacitor. Here, the first capacitor and Figure 1 The function of the conventional capacitor Cout in the embodiment is the same as that of a filter capacitor. The second end of the first capacitor is grounded. The second output end of the bootstrap boost circuit serves as a bootstrap voltage output end, connected to the control end of the first switch tube, and the second end of the first switch tube is connected to the server motherboard. The bootstrap voltage of the bootstrap voltage output end in this embodiment is used to drive the control end of the first switch tube to perform on-off operations, so as to power the server motherboard.

[0070] It is worth noting that since the step-down circuit does not work when the whole machine is unplugged for maintenance, when the whole machine is plugged in again, there will be a momentary charging of the first capacitor at the first moment to generate a large impact current. At the current first moment, since the whole machine has just been plugged in, its step-down circuit is in a non-working state, the corresponding bootstrap voltage is 0V, and the control end given to the first switch tube is 0V, so the first switch tube is turned off until it receives the backup power instruction, that is, the high and low level signals given to the output end of the control module. At this time, the first output end of the bootstrap boost circuit rises from 0V, and its second output end gives a corresponding rising process, resulting in the bootstrap voltage of the bootstrap voltage output end being higher than the voltage of the first output end, and it drives the control end of the first switch tube to turn on.

[0071] There is no limitation on the type of the first switch tube, which can be a transistor or a metal-oxide-semiconductor field-effect transistor (MOS). There is no limitation on the specific channel type of the MOS tube. In some embodiments, an NMOS tube is selected in consideration of the small impedance inside the tube.

[0072] The embodiment of the present invention provides a step-down circuit, which includes a control module, a bootstrap boost circuit, a first capacitor and a first switch tube; the output end of the control module is connected to the input end of the bootstrap boost circuit; it is used to control the bootstrap boost circuit to output a bootstrap voltage; the first output end of the bootstrap boost circuit is connected to the first end of the first capacitor and the first end of the first switch tube; the second end of the first capacitor is grounded; the second output end of the bootstrap boost circuit serves as the bootstrap voltage output end and is connected to the control end of the first switch tube; the second end of the first switch tube is connected to the server motherboard. The bootstrap boost circuit is combined with the first switch tube. When the power supply voltage of the server motherboard is loaded to the second end of the first switch tube, the first switch tube is disconnected because the voltage of the bootstrap voltage output end of the current bootstrap boost circuit is 0V. At this time, the first switch tube is used to prevent backflow. On the basis of the first switch tube preventing backflow to the first capacitor from overcurrent, the bootstrap boost circuit is added. At the second moment of hot plugging, the output voltage of the circuit is increased by using the low-level signal given by the output end of the control module and the bootstrap technology, that is, the level signal given by the output end of the control module to the bootstrap boost circuit is used to output the bootstrap voltage as the driving voltage of the first switch tube to drive and control the conduction of the first switch tube. In the case of preventing the overcurrent of the impact current caused by hot plugging, the conduction of the first switch tube is driven by a sufficiently high driving voltage, which improves the driveability of the output voltage and also improves the maintenance operability of the backup power module.

[0073] In some embodiments, Figure 2As shown, the bootstrap boost circuit 3 includes a transformer L1, a first diode D1 and a second capacitor C2; the transformer L1 includes a first winding and a second winding;

[0074] The same-name end of the first winding serves as the input end of the bootstrap boost circuit 3 and is connected to the control end of the buck circuit;

[0075] The opposite-name end of the first winding serves as the first output end of the bootstrap boost circuit 3 and is connected to the first end of the first capacitor C1, the same-name end of the second winding and the first end of the first switch tube Q1;

[0076] The opposite-name end of the second winding is connected to the anode of the first diode D1; the cathode of the first diode D1 is connected to the first end of the second capacitor C2 and to the control end of the first switch tube Q1;

[0077] The common end of the first diode D1 and the second capacitor C2 serves as the second output end of the bootstrap boost circuit 3 ; the second end of the second capacitor C2 is grounded.

[0078] It is understandable that, combined with Figure 1 and Figure 2 In this embodiment, the transformer is replaced by Figure 1 The inductor is used to build a bootstrap boost circuit. The first winding of the transformer is used as the primary winding, and the second winding is used as the secondary winding. Figure 2 The transformer in the figure is from top to bottom, which are the first winding and the second winding. A transformer is an electrical device that uses the principle of electromagnetic induction to change the voltage or current. It consists of two or more windings, which are usually wound on the same iron core. The same-named terminals correspond to the current inflow and outflow ends of the first and second windings of the transformer, and are represented by the same mark or symbol. Figure 2 The term “·” is used in the figure. The current inflow and outflow of the first winding and the second winding of the transformer do not correspond to each other, that is, the inflow of the first winding corresponds to the outflow of the second winding, and the outflow of the first winding corresponds to the inflow of the second winding.

[0079] The first winding of the transformer is connected to Figure 1 The inductor is located at the same end as the first one, and the same end is connected to the control end of the step-down circuit, and the opposite end is connected to the first end of the first capacitor, and the Vtemp voltage is output. The same end of the second winding of the transformer is connected to the first end of the first capacitor, that is, the Vtemp voltage is output, the opposite end of the second winding is connected to the anode of the first diode, the cathode of the first diode is connected to the first end of the second capacitor, and the second end of the second capacitor is grounded. The first diode charges the second capacitor by conducting to generate the second output end (bootstrap voltage output end Vboot) of the bootstrap boost circuit to drive the drive signal Vgate of the control end of the first switch tube to conduct.

[0080] The bootstrap boost circuit formed by the transformer provided in this embodiment increases the voltage and generates a voltage higher than the power supply voltage, which corresponds to the control end driving the first switch tube, generates a larger driving performance, and can increase the voltage without increasing the current, thereby reducing power loss. In addition, the transformer can provide electrical isolation and improve safety.

[0081] Regarding the coil turns ratio of the first winding and the second winding in the transformer mentioned in the above embodiments, in some embodiments, the coil turns ratio of the first winding and the second winding is 1:1, which can be equivalent to an ideal transformer with the same number of coil turns on both sides to achieve an instantaneous voltage increase. At the moment of the switch action, a momentary high voltage is generated through the charging and discharging process of the second capacitor to provide a stronger switch driving capability and improve the switching characteristics.

[0082] In some other embodiments, the process of determining the coil turns ratio of the first winding and the second winding includes:

[0083] Obtaining a threshold voltage and a critical voltage of the first switch tube;

[0084] Determine a driving voltage range of the first switch tube according to the threshold voltage and the critical voltage;

[0085] Determine the bootstrap voltage range of the bootstrap boost circuit according to the driving voltage range;

[0086] The coil turns ratio is determined according to the bootstrap voltage range of the bootstrap boost circuit.

[0087] It is understandable that the threshold voltage and critical voltage of the first switch tube are determined based on the characteristics of the first switch tube itself, so as to determine the driving voltage range of the first switch tube. For example, considering the safety of the first switch tube, it provides a certain safety buffer to ensure normal operation within the driving voltage range. If the driving voltage is lower than 3V, the first switch tube cannot be fully turned on. If it is higher than 20V, it will cause damage to the first switch tube. Therefore, the driving voltage range of the first switch tube is 3-20V, where 3V is the threshold voltage and 20V is the critical voltage.

[0088] The bootstrap voltage range is determined according to the driving voltage range, which ensures that the coil turns ratio is determined according to the bootstrap voltage range under the driving voltage range. Taking the above driving voltage range of 3-20V as an example, the power supply voltage of the server motherboard is 12V, and the corresponding coil turns ratio can be 1:1 or 1:0.5, so that the bootstrap voltage (Vboot= (1*Vtemp+N*Vtemp)) can be around 20V, where N is the turns ratio of the second winding.

[0089] In the process of determining the coil turns ratio in this embodiment, since the bootstrap voltage drives the control end of the first switch tube, it is necessary to determine the voltage values ​​corresponding to the first output end of the bootstrap boost circuit and the bootstrap voltage output end in combination with the coil turns ratio, and then drive the first switch tube to turn on and off, thereby ensuring the diversity and flexibility of the driving range of the first switch tube.

[0090] In some embodiments, Figure 2 As shown, the transformer of the bootstrap boost circuit 3 and the first capacitor C1 form a first filter circuit 4.

[0091] It can be understood that the transformer of the bootstrap boost circuit in this embodiment replaces Figure 1 An inductor is used to construct a bootstrap boost circuit, and its transformer takes over the role of the inductor and forms a first filter circuit with the first capacitor, so as to smooth the pulse current generated by the switching action and provide a stable DC output voltage.

[0092] In this embodiment, a first filtering circuit is formed by a transformer and a first capacitor to smooth the pulse voltage generated by the switching action, reduce the ripple of the output voltage, prevent the output voltage fluctuation caused by load changes or input voltage fluctuations, and improve the transient load response performance.

[0093] In some embodiments, Figure 2 As shown, it also includes a second filtering circuit 5;

[0094] A first end of the second filter circuit 5 is connected to the bootstrap voltage output end of the bootstrap boost circuit 3;

[0095] The second end of the second filter circuit 5 is connected to the control end of the first switch tube Q1 .

[0096] It can be understood that the second filter circuit plays a delay role in this embodiment, so that the voltage Vgate at the control end of the current first switch tube lags behind the bootstrap voltage at the bootstrap voltage output end, delaying the turning on of the first switch tube.

[0097] The second filter circuit provided in this embodiment realizes the setting of soft switch, that is, when the switch tube is turned on, there is no sudden change, which helps to reduce the electromagnetic interference of the switch and improve the efficiency. At the same time, it reduces the voltage drop of the first switch tube when it is turned on, and improves the efficiency of the whole circuit.

[0098] The specific components corresponding to the second filtering circuit and the connection relationship between the components are not limited and can be set according to actual conditions.

[0099] In some embodiments, Figure 2 As shown, the second filtering circuit 5 includes a first resistor R1 and a third capacitor C3;

[0100] A first end of the first resistor R1 is connected to a bootstrap voltage output end of the bootstrap boost circuit 3;

[0101] The second end of the first resistor R1 is connected to the control end of the first switch tube Q1 and is connected to the first end of the third capacitor C3;

[0102] A second terminal of the third capacitor C3 is grounded.

[0103] Specifically, the second filter circuit is formed by a combination of resistors and capacitors, so that the voltage Vgate at the control end of the first switch tube lags behind the bootstrap voltage at the bootstrap voltage output end, ensuring that the first switch tube is turned on when Vtemp rises to the power supply voltage of the server motherboard.

[0104] The second filter circuit provided in this embodiment, which is composed of a combination of resistors and capacitors, can remove high-frequency noise and smooth the pulses generated by the switching action, thereby reducing the ripple and fluctuation of the output voltage. In addition, it is used to stabilize the voltage and resist short-term fluctuations of the input voltage through the charging and discharging process of the capacitor.

[0105] In some other embodiments, based on the first resistor and the third capacitor in the above embodiments, the second filtering circuit further includes a second diode;

[0106] An anode of the second diode is connected to the second end of the first resistor and the first end of the third capacitor;

[0107] The cathode of the second diode is connected to the control end of the first switch tube.

[0108] Specifically, the second diode has a detection function and also plays a role in adjusting the threshold level, further optimizing the bootstrap voltage output signal of the bootstrap boost circuit. The threshold voltage of the first diode refers to the voltage at which the diode changes from a cut-off state to a conduction state, and its voltage is usually between 0.6V and 0.7V, depending on the type of diode. In this embodiment, the corresponding diode type is not limited and can be set according to actual conditions.

[0109] In some embodiments, there is no limitation on the number of the second diodes, that is, there are N second diodes, where N is a positive integer greater than or equal to 1, and the N second diodes are connected in series;

[0110] An anode of the first second diode is connected to the second end of the first resistor and the first end of the third capacitor;

[0111] The cathode of the last second diode is connected to the control end of the first switch tube.

[0112] The present embodiment provides a plurality of second diodes connected in series, which can flexibly adjust the threshold voltage of the circuit on the basis of improving the filtering performance of the second filtering circuit to meet different design requirements, so that the first switch tube can be stably turned on at a specific voltage.

[0113] In some embodiments, Figure 2 As shown, the control module 6 includes a control unit 7, a second switch tube Q2 and a third switch tube Q3;

[0114] The control unit 7 is connected to the control end of the second switch tube Q2 and the control end of the third switch tube Q3; the second end of the second switch tube Q2 is connected to the first end of the third switch tube Q3 and serves as the output end of the control module 6;

[0115] The positive electrode of the power supply is connected to the first end of the second switch tube Q2; the negative electrode of the power supply is connected to the second end of the third switch tube Q3 and is grounded.

[0116] Specifically, the control module includes a control unit, a second switch tube and a third switch tube. The third switch tube replaces the freewheeling diode of the basic buck circuit to play the role of synchronous rectification. The control unit connects the control end of the second switch tube and the control end of the third switch tube; the second end of the second switch tube is connected to the first end of the third switch tube and serves as the output end of the control module; the positive electrode of the power supply is connected to the first end of the second switch tube; the negative electrode of the power supply is connected to the second end of the third switch tube and is grounded, so that the second switch tube and the third switch tube are alternately turned on. It can be understood that the alternating on and off of the second switch tube and the third switch tube are used to control the output signal of the output end of the module to control the operation of the bootstrap boost circuit and output the bootstrap voltage.

[0117] When the second switch is turned off and the third switch is turned on, the output of the control module outputs a low level, the first winding of the transformer is subjected to a -Vtemp voltage drop, and the voltage at the same-name end is negative. Due to the mutual inductance, the second winding will also sense the -Vtemp voltage, and the voltage at the same-name end is negative, while the voltage at the opposite-name end is positive. The voltage at the same-name end of the second winding is Vtemp, so the voltage at the opposite-name end of the second winding is 2Vtemp. At the moment the buck circuit is turned on, Vtemp=Vboot=0V. As the output voltage Vtemp of the buck circuit gradually rises from 0V to 12V, the voltage at the opposite-name end 2Vtemp charges the second capacitor through the first diode, charging Vboot to 2Vtemp, and Vboot also rises from 0V to 24V.

[0118] When the second switch tube is turned on and the third switch tube is turned off, the output end of the control module outputs a high level, the first winding of the transformer is subjected to the Vbat-Vtemp voltage drop, the voltage at the same-name end is positive, and the second winding will also induce the Vbat-Vtemp voltage due to mutual inductance, the voltage at the same-name end is positive, and the voltage at the opposite-name end is negative. The voltage at the same-name end of the second winding is Vtemp, so the voltage at the opposite-name end of the second winding is 2Vtemp-Vbat. From the previous step, it can be seen that Vboot=2Vtemp, and the first diode is subjected to the reverse voltage drop and is turned off, preventing the second capacitor from discharging through the first diode. In other words, due to the unidirectional conduction characteristic of the first diode, only the second capacitor can be charged during the operation of the buck circuit.

[0119] The connection relationship between the control unit and the second switch tube and the third switch tube in the control module provided in this embodiment is realized by giving control signals to the second switch tube and the third switch tube through the control unit, so as to realize the alternating conduction of the second switch tube and the third switch tube, so as to control the output of the bootstrap voltage of the bootstrap boost circuit, reduce energy consumption and improve conduction efficiency.

[0120] Furthermore, the present invention also provides a backup power module, comprising the above-mentioned step-down circuit.

[0121] For an introduction to a backup power module provided by the present invention, please refer to the above method embodiment, and the present invention will not be repeated here. It has the same beneficial effects as the above-mentioned step-down circuit.

[0122] Furthermore, the present invention also provides a server, Figure 3 A structural diagram of a server provided in an embodiment of the present invention, such as Figure 3 As shown, it includes a server mainboard 2 and the above-mentioned backup power module 8;

[0123] The output end of the backup power module 8 is connected to the server mainboard 2 .

[0124] For an introduction to a server provided by the present invention, please refer to the above method embodiment, and the present invention will not be repeated here. It has the same beneficial effects as the above backup power module.

[0125] Furthermore, the present invention also provides a step-down charging method, which is applied to a step-down circuit, wherein the step-down circuit includes a control module, a bootstrap boost circuit, a first capacitor and a first switch tube; the output end of the control module is connected to the input end of the bootstrap boost circuit; the first output end of the bootstrap boost circuit is connected to the first end of the first capacitor and to the first end of the first switch tube; the second end of the first capacitor is grounded; the second output end of the bootstrap boost circuit serves as a bootstrap voltage output end and is connected to the control end of the first switch tube; the second end of the first switch tube is connected to a server motherboard; Figure 4 A flowchart of a voltage reduction charging method provided by an embodiment of the present invention is shown in FIG. Figure 4As shown, the method includes:

[0126] S11: when the output end of the control module is connected to the input end of the bootstrap boost circuit at the first moment of hot plugging, the bootstrap voltage at the bootstrap voltage output end of the bootstrap boost circuit is controlled to be 0V, so as to drive the first switch tube to be turned off;

[0127] S12: When the output end of the control module outputs a level signal at the second moment of hot plugging, the bootstrap voltage output end of the bootstrap boost circuit is controlled to output a bootstrap voltage so as to drive the first switch tube to conduct.

[0128] It can be understood that the application scenario corresponding to this embodiment is the turning on and off of the first switch tube at different moments during hot plugging.

[0129] Combining the above embodiments Figure 2 When the backup power module is just inserted into the whole machine after maintenance, the buck circuit is not working. At this time, Vtemp=Vout=Vboot=0V, the first switch tube is in the off state, and Vout is connected to the combined voltage P12V_AUX through the power connector J1 and the power connector J2 of the server motherboard. The voltage is instantly pulled to 12V. Since Vgs=0V (the threshold voltage of the first switch tube), the first switch tube is still in the off state at this time, preventing 12V from charging the first capacitor, thereby avoiding the instantaneous impact current generated when the backup power module is inserted into the whole machine.

[0130] When the backup power module receives the backup power command from the system, the buck circuit starts to work to reduce the voltage of Vbat to 12V for output, and the output end of the control module gives a corresponding level signal. When the output end of the control module is at a low level, the first winding of its transformer is subjected to a -Vtemp voltage drop, and the voltage at the same-name end is negative. Due to the mutual inductance, the second winding will also induce a -Vtemp voltage, and the voltage at the same-name end is negative, and the voltage at the opposite-name end is positive. The voltage at the same-name end of the second winding is Vtemp, so the voltage at the opposite-name end of the second winding is 2Vtemp. At the moment the buck circuit is turned on, Vtemp=Vboot=0V. As the output voltage Vtemp of the buck circuit gradually rises from 0V to 12V, the voltage 2Vtemp at the same-name end charges the second capacitor through the first diode, charging Vboot to 2Vtemp. Vboot also rises from 0V to 24V. At this time, the bootstrap voltage is greater than the first output end of the bootstrap boost circuit. At the same time, considering the power supply voltage of the server motherboard, when the first output end of the bootstrap boost circuit reaches the power supply voltage of the server motherboard, the control end of the first switch tube is driven to turn on the first switch tube.

[0131] When the output end of the control module is at a high level, the first winding of the transformer is subjected to a Vbat-Vtemp voltage drop, and the voltage at the same-name end is positive. Due to the mutual inductance, the second winding will also induce a Vbat-Vtemp voltage, and the voltage at the same-name end is positive, and the voltage at the opposite-name end is negative. The voltage at the same-name end of the second winding is Vtemp, so the voltage at the opposite-name end of the second winding is 2Vtemp-Vbat. From the previous step, it can be seen that Vboot=2Vtemp, and the first diode is subjected to a reverse voltage drop and is turned off to prevent the second capacitor from discharging through the first diode. In other words, due to the unidirectional conduction characteristic of the first diode, only the second capacitor can be charged during the operation of the buck circuit. At this time, the bootstrap voltage is greater than the voltage at the first output end of the bootstrap boost circuit, and the voltage at the control end of the first switch tube is greater than the threshold voltage of the first switch tube. The first switch tube is in the on state to power the server motherboard.

[0132] The present invention provides a step-down charging method. When the output end of the control module is connected to the input end of the bootstrap boost circuit at the first moment of hot plugging, the bootstrap voltage of the bootstrap voltage output end of the bootstrap boost circuit is controlled to be 0V, so as to drive the first switch tube to be disconnected; when the output end of the control module outputs a level signal at the second moment of hot plugging, the bootstrap voltage output end of the bootstrap boost circuit is controlled to output a bootstrap voltage, so as to drive the first switch tube to be turned on. The bootstrap boost circuit is combined with the first switch tube. When the power supply voltage of the server mainboard is loaded to the second end of the first switch tube, since the voltage of the bootstrap voltage output end of the current bootstrap boost circuit is 0V, the first switch tube is disconnected. At this time, the first switch tube is used to prevent backflow. On the basis of the first switch tube preventing backflow to the first capacitor from overcurrent, a bootstrap boost circuit is added. At the second moment of hot plugging, the output voltage of the circuit is increased by using the level signal given by the output end of the control module and the bootstrap technology, that is, the level signal given by the output end of the control module to the bootstrap boost circuit is used to output the bootstrap voltage as the driving voltage of the first switch tube to drive and control the conduction of the first switch tube. In the case of preventing the overcurrent of the impact current caused by hot plugging, the conduction of the first switch tube is driven by a sufficiently high driving voltage, which improves the driveability of the output voltage and also improves the maintenance operability of the backup power module.

[0133] In addition, when Vtemp rises to 12V, the buck circuit can discharge to the server motherboard through the first switch tube. At this time, the first switch tube of the NMOS tube will also be turned on under the drive of the bootstrap voltage to prevent the discharge current from flowing through the parasitic body diode of the first switch tube, thereby avoiding voltage drop loss and heating of the first switch tube.

[0134] It can be understood that the internal battery of the backup power module takes 4 18650 ternary lithium batteries as an example. The maximum voltage of a single cell is 4.2V, and the maximum voltage of 4 cells is 16.8V. The buck circuit steps down Vbat to 12V for output. The number of turns of the first and second windings of the transformer is 1 turn, the excitation inductance is 1.2uH, the output first capacitor is 220uF, and the first switch tube is CSD16415. Since the current flowing through the second winding is only used to drive the gate of the first switch tube, the current is very small. The first diode is 1N4148, the second capacitor is 10uF, and it is assumed that the slow start time of the buck circuit is 1ms, let the first resistor R1=10k, the third capacitor C3=100nF, and the time constant of the RC delay circuit (second filter circuit) is also 1ms.

[0135] Figure 5 A voltage timing diagram of a backup power module in a hot-swap scenario provided by an embodiment of the present invention, such as Figure 5 As shown, the horizontal axis is the time information (ms), and the vertical axis is the voltage; wherein, the serial number "①" represents the combined voltage P12V_AUX; the serial number "②" represents the bootstrap voltage Vboot of the second output end of the bootstrap boost circuit; the serial number "③" represents the output voltage end Vout of the buck circuit, and the serial number "④" represents the voltage Vgate of the control end of the first switch tube. Within 0~1ms, the backup power module has just been inserted into the server motherboard. At this time, the combined voltage P12V_AUX of the motherboard is immediately loaded to the output voltage end Vout of the buck circuit, causing Vout to rise to 12V. However, the voltage Vgate of the control end of the first switch tube is 0V, and the first switch tube is turned off, so 12V will not be backflowed to the first capacitor, and no impact current will be generated.

[0136] At 1ms, the backup power module receives the backup power command from the system, and the buck circuit starts working. The voltage Vtemp at the first output end of the bootstrap boost circuit rises from 0V at 1ms to 12V at 2ms, and the bootstrap voltage Vboot at the second output end of the bootstrap boost circuit rises from 0V to 24V within this time range. Due to the action of the second filter circuit, the voltage Vgate at the control end of the first switch tube is only 8V at 2ms, and the threshold voltage Vgs of the first switch tube is Vgate-Vtemp=-4V. Therefore, the first switch tube will not be turned on during this period, and no impact current will be generated.

[0137] At 3ms, the control terminal voltage Vgate of the first switch tube rises to 18V, and the threshold voltage Vgs of the first switch tube is 6V, which exceeds the turn-on voltage threshold. Therefore, the first switch tube is turned on, and the buck circuit can discharge to the server motherboard through the first switch tube. At this time, even if the first switch tube is not turned on, the buck circuit can discharge through the parasitic body diode of the first switch tube, but the body diode voltage drop is relatively large, resulting in power loss and causing the first switch tube to heat up. After the first switch tube is turned on, due to the extremely low on-resistance, the voltage drop between the drain and source of the first switch tube becomes smaller, thereby avoiding loss and heating problems.

[0138] Figure 6 A structural diagram of a step-down charging device provided by an embodiment of the present invention, such as Figure 6 As shown, the device comprises:

[0139] A memory 21, used for storing computer programs;

[0140] The processor 22 is used to implement the steps of the voltage reduction charging method when executing the computer program.

[0141] Among them, the processor 22 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 22 may be implemented in at least one hardware form of a digital signal processor (DSP), a field-programmable gate array (FPGA), and a programmable logic array (PLA). The processor 22 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a central processing unit (CPU); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 22 may be integrated with a graphics processing unit (GPU), which is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 22 may also include an artificial intelligence (AI) processor, which is used to process computing operations related to machine learning.

[0142] The memory 21 may include one or more computer-readable storage media, which may be non-transitory. The memory 21 may also include a high-speed random access memory, and a non-volatile memory, such as one or more disk storage devices, flash memory storage devices. In this embodiment, the memory 21 is at least used to store the following computer program 211, wherein the computer program is loaded and executed by the processor 22, and the relevant steps of the step-down charging method disclosed in any of the aforementioned embodiments can be implemented. In addition, the resources stored in the memory 21 may also include an operating system 212 and data 213, etc., and the storage method may be temporary storage or permanent storage. Among them, the operating system 212 may include Windows, Unix, Linux, etc. Data 213 may include, but is not limited to, data involved in the step-down charging method, etc.

[0143] In some embodiments, the step-down charging device may further include a display screen 23 , an input / output interface 24 , a communication interface 25 , a power source 26 , and a communication bus 27 .

[0144] Those skilled in the art can understand that Figure 6 The structure shown in the figure does not constitute a limitation on the buck charging device, and may include more or fewer components than those shown in the figure.

[0145] The processor 22 implements the voltage reduction charging method provided in any of the above embodiments by calling the instructions stored in the memory 21 .

[0146] For an introduction to a step-down charging device provided by the present invention, please refer to the above method embodiment, and the present invention will not be repeated here. It has the same beneficial effects as the above step-down charging method.

[0147] Furthermore, the present invention also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by the processor 22, the steps of the above-mentioned step-down charging method are implemented.

[0148] It is understandable that if the method in the above embodiment is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium to execute all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk and other media that can store program codes.

[0149] For an introduction to a computer-readable storage medium provided by the present invention, please refer to the above method embodiment, and the present invention will not be repeated here. It has the same beneficial effects as the above-mentioned step-down charging method.

[0150] Furthermore, the present invention also provides a computer program product, including a computer program / instruction, which implements the steps of the step-down charging method when executed by a processor.

[0151] For an introduction to a computer program product provided by the present invention, please refer to the above method embodiment, which will not be described in detail herein. It has the same beneficial effects as the above-mentioned step-down charging method.

[0152] The above is a detailed introduction to a step-down circuit, a backup power module, a server, a step-down charging method and a device provided by the present invention. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the embodiments can refer to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can refer to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the present invention.

[0153] It should also be noted that, in this specification, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A server, characterized in that: It includes a server mainboard and a backup power module; the output end of the backup power module is connected to the server mainboard; the backup power module includes a step-down circuit; the step-down circuit includes a control module, a bootstrap boost circuit, a first capacitor and a first switch tube; The output end of the control module is connected to the input end of the bootstrap boost circuit; and is used to control the bootstrap boost circuit to output a bootstrap voltage; The first output end of the bootstrap boost circuit is connected to the first end of the first capacitor and the first end of the first switch tube; the second end of the first capacitor is grounded; The second output end of the bootstrap boost circuit serves as a bootstrap voltage output end and is connected to the control end of the first switch tube; the second end of the first switch tube is connected to the server mainboard; The bootstrap boost circuit is used to drive the first switch tube to turn off when the bootstrap voltage outputted at the first moment of hot plugging is 0V; and to drive the first switch tube to turn on when the bootstrap voltage outputted at the level signal of the output end of the control module at the second moment of hot plugging; Correspondingly, the bootstrap boost circuit includes a transformer, a first diode and a second capacitor; the transformer includes a first winding and a second winding; The same-name end of the first winding serves as the input end of the bootstrap boost circuit and is connected to the common end of the second switch tube and the third switch tube of the control module; The opposite-name end of the first winding serves as the first output end of the bootstrap boost circuit and is connected to the first end of the first capacitor, the same-name end of the second winding and the first end of the first switch tube; The opposite-name end of the second winding is connected to the anode of the first diode; the cathode of the first diode is connected to the first end of the second capacitor and is connected to the control end of the first switch tube; The common end of the first diode and the second capacitor serves as the second output end of the bootstrap voltage boost circuit; the second end of the second capacitor is grounded.

2. The server according to claim 1, characterized in that: The process of determining the coil turns ratio of the first winding and the second winding includes: Obtaining a threshold voltage and a critical voltage of the first switch tube; Determining a driving voltage range of the first switch tube according to the threshold voltage and the critical voltage; Determining a bootstrap voltage range of the bootstrap boost circuit according to the driving voltage range; The coil turns ratio is determined according to the bootstrap voltage range of the bootstrap voltage boost circuit.

3. The server according to claim 1, characterized in that: The coil turns ratio of the first winding and the second winding is 1:

1.

4. The server according to claim 1, characterized in that: The transformer of the bootstrap boost circuit and the first capacitor form a first filter circuit.

5. The server according to claim 1, characterized in that: Also comprising a second filtering circuit; The first end of the second filter circuit is connected to the bootstrap voltage output end of the bootstrap boost circuit; The second end of the second filter circuit is connected to the control end of the first switch tube.

6. The server according to claim 5, characterized in that: The second filtering circuit includes a first resistor and a third capacitor; The first end of the first resistor is connected to the bootstrap voltage output end of the bootstrap boost circuit; The second end of the first resistor is connected to the control end of the first switch tube and is connected to the first end of the third capacitor; A second terminal of the third capacitor is grounded.

7. The server according to claim 6, characterized in that: The second filtering circuit further includes a second diode; An anode of the second diode is connected to the second end of the first resistor and the first end of the third capacitor; The cathode of the second diode is connected to the control end of the first switch tube.

8. The server according to claim 1, characterized in that: The control module includes a control unit, a second switch tube and a third switch tube; The control unit is connected to the control end of the second switch tube and the control end of the third switch tube; the second end of the second switch tube is connected to the first end of the third switch tube and serves as the output end of the control module; The positive electrode of the power supply is connected to the first end of the second switch tube; the negative electrode of the power supply is connected to the second end of the third switch tube and is grounded.

9. A step-down charging method, characterized in that: Applied to the server of claim 1; the method comprising: When the output end of the control module is connected to the input end of the bootstrap boost circuit at the first moment of hot plugging, the bootstrap voltage of the bootstrap voltage output end of the bootstrap boost circuit is controlled to be 0V, so as to drive the first switch tube to be turned off; When the output end of the control module outputs a level signal at the second moment of hot plugging, the bootstrap voltage output end of the bootstrap boost circuit is controlled to output a bootstrap voltage so as to drive the first switch tube to turn on.

10. A step-down charging device, characterized in that: include: Memory for storing computer programs; A processor is used to implement the steps of the step-down charging method as claimed in claim 9 when executing the computer program.

11. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by the processor, the steps of the step-down charging method according to claim 9 are implemented.

12. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, the steps of the step-down charging method according to claim 9 are implemented.

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