Bootstrap charge pump circuit and energy storage power supply thereof

Abstract

The embodiment of the utility model discloses a bootstrap charge pump circuit and an energy storage power supply thereof. The bootstrap charge pump circuit comprises a charge pump module; the pre-charging module is connected with the charge pump module and is configured to pre-charge the charge pump module before the bus is conducted, so that the charge pump module outputs driving voltage; the control module is configured to be used for outputting a control signal; the bus switch module is connected with the charge pump module and the control module, and is configured to control the connection and disconnection of a bus according to the driving voltage and the control signal; and the voltage protection module is connected with the output end of the charge pump module and is configured to absorb an induced voltage peak from a bus inductor when the bus is disconnected and limit the driving voltage within a preset voltage range. According to the embodiment of the utility model, the induced voltage peak generated by the bus inductor when the bus is disconnected is absorbed through the voltage protection module, and the driving voltage is limited in the preset voltage range, so that the possibility that the charge pump stores voltage peak energy to cause continuous voltage rise to damage devices is avoided.

Description

Technical Field

[0001] This utility model relates to the field of charge pumps, and in particular to a bootstrap charge pump circuit and its energy storage power supply. Background Technology

[0002] In switching power supplies, charge pumps are commonly used as drive power sources to power back-to-back N-MOS transistors as bus switches. In practical applications, these N-MOS transistors may be switched repeatedly and rapidly. If a large-capacity common-mode or differential-mode inductor is connected in series in the bus, induced voltage spikes will be generated due to current cutoff. Because of the characteristics of charge pump applications—that the voltage across the capacitor cannot change abruptly—this spike energy will be stored by the charge pump, causing the charge pump voltage to continuously increase. This high voltage can potentially damage the devices. Utility Model Content

[0003] The main technical problem solved by this utility model embodiment is to provide a bootstrap charge pump circuit and its energy storage power supply, which can solve at least some of the defects of existing charge pumps.

[0004] In a first aspect, this utility model provides a bootstrap charge pump circuit, comprising: a charge pump module; a pre-charge module connected to the charge pump module and configured to pre-charge the charge pump module before the bus is turned on, so that the charge pump module outputs a drive voltage; a control module configured to output a control signal; a bus switch module connected to the charge pump module and the control module and configured to control the turn-on and turn-off of the bus according to the drive voltage and the control signal; and a voltage protection module connected to the output terminal of the charge pump module and configured to absorb induced voltage spikes from the bus inductance when the bus is turned off and limit the drive voltage within a preset voltage range.

[0005] Optionally, the voltage protection module includes a voltage suppressor connected between the first and second output terminals of the charge pump module, configured to turn on when the driving voltage exceeds a preset voltage threshold, so as to absorb the induced voltage spike and clamp the driving voltage within a preset voltage range.

[0006] Optionally, the voltage suppressor is a transient voltage suppressor diode, which is connected between the first output terminal and the second output terminal of the charge pump module.

[0007] Optionally, the bus switch module includes: a drive unit connected to the control module and the charge pump module, configured to output a drive signal in response to the drive voltage and the control signal; and a switch unit connected to the drive unit, configured to control the conduction and disconnection of the bus according to the drive signal.

[0008] Optionally, the switching unit includes a first switching transistor, a fourth switching transistor, a fourth resistor, a sixth resistor, a seventh resistor, and an eighth resistor; the gate of the first switching transistor is connected to the first terminal of the fourth resistor and the first terminal of the seventh resistor; the drain of the first switching transistor is connected to a bus inductor; the source of the first switching transistor is connected to the source of the fourth switching transistor, the second terminal of the seventh resistor, and the second terminal of the sixth resistor; the gate of the fourth switching transistor is connected to the first terminal of the sixth resistor and the first terminal of the eighth resistor; the drain of the fourth switching transistor is connected to a bus inductor; and the second terminals of the eighth resistor and the fourth resistor are both connected to the output terminal of the driving unit.

[0009] Optionally, the driving unit includes a first switch and a second switch; the control terminal of the first switch is connected to the control module, the first terminal of the first switch is connected to the first output terminal of the charge pump module, the second terminal of the first switch is connected to the first terminal of the second switch, the second terminal of the eighth resistor, and the second terminal of the fourth resistor, the control terminal of the second switch is connected to the control module, and the second terminal of the second switch is connected to the second output terminal of the charge pump module; wherein, when the first switch is closed and the second switch is open, the first switch transistor and the fourth switch transistor are turned on; when the first switch is open and the second switch is closed, the first switch transistor and the fourth switch transistor are turned off.

[0010] Optionally, the charge pump module includes a fifth switch, a first resistor, a second resistor, a ninth resistor, a first capacitor, a second capacitor, a first diode, and a second diode; the base of the fifth switch is connected to the first end of the ninth resistor, the second end of the ninth resistor receives a control voltage, the collector of the fifth switch is connected to the first end of the first resistor and the first end of the first capacitor, the second end of the first resistor is connected to a voltage source, the second end of the first capacitor is connected to the anode of the first diode and the cathode of the second diode, the cathode of the first diode is connected to the first end of the second capacitor, the second end of the second capacitor is connected to the anode of the second diode and the first end of the second resistor, and the second end of the second resistor and the emitter of the fifth switch are connected to a reference ground.

[0011] Optionally, the precharge module includes a third diode and a third resistor; the anode of the third diode is connected to a voltage source, the cathode of the third diode is connected to a first end of the third resistor, and the second end of the third resistor is connected to the output terminal of the charge pump module.

[0012] Optionally, the bus inductor is connected in series in the bus, and the bus inductor includes at least one of common-mode inductor and differential-mode inductor.

[0013] Secondly, this utility model also provides an energy storage power supply, including: a bootstrap charge pump circuit as described in the first aspect.

[0014] The beneficial effects of this utility model embodiment are as follows: Unlike the prior art, this utility model embodiment sets a voltage protection module at the output end of the charge pump module to absorb the induced voltage spike generated by the bus inductance when the bus is disconnected, and limits the driving voltage to a preset voltage range, so as to avoid the possibility of the charge pump storing voltage spike energy causing the voltage to rise continuously and thus damaging the device, thereby improving the safety and reliability of the charge pump. Attached Figure Description

[0015] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0016] Figure 1 This is the circuit schematic of an existing bootstrap charge pump circuit;

[0017] Figure 2 This is a schematic diagram of a bootstrap charge pump circuit provided in an embodiment of this application;

[0018] Figure 3 This is a circuit diagram of a bootstrap charge pump circuit provided in an embodiment of this application. Detailed Implementation

[0019] To facilitate understanding of this utility model, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as being "fixed to" another element, it can be directly on the other element, or one or more intermediate elements may exist between them. When an element is described as being "connected" to another element, it can be directly connected to the other element, or one or more intermediate elements may exist between them. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this specification are for illustrative purposes only.

[0020] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0021] The following is a terminology explanation for some of the terms mentioned in the embodiments of this application:

[0022] A bootstrap charge pump is a special circuit structure used to generate a drive voltage higher than the system supply voltage. This circuit utilizes the charging and discharging characteristics of capacitors, periodically switching on and off to "pump" charge from one capacitor to another, thereby boosting the voltage. In power electronics, bootstrap charge pumps are commonly used to drive high-side N-channel MOSFETs. Since the gate voltage of an N-channel MOSFET needs to be higher than its source voltage to turn on, and the source potential of a high-side MOSFET is often floating, a bootstrap charge pump can provide a stable drive voltage relative to the source of the high-side MOSFET.

[0023] Back-to-back switching refers to a configuration where two switching transistors (usually MOSFETs) are connected in series in a specific manner. In a typical back-to-back N-MOS configuration, the sources or drains of the two N-channel MOSFETs are connected together, forming a bidirectional control structure. In power supply systems, back-to-back switching transistors are commonly used as bus switches to control the connection and disconnection of power input and output. This configuration is particularly important in applications requiring bidirectional isolation, such as battery management systems, AC switching circuits, and bidirectional DC / DC converters.

[0024] Transient voltage suppressor diodes (TVS diodes) are semiconductor devices specifically designed to protect electronic circuits from damage caused by transient high voltages. Their core function is to quickly turn on when a voltage spike exceeding a preset threshold is detected, absorbing or shunting the excess energy and clamping the voltage in the circuit within a safe range.

[0025] Induced voltage spikes are high-voltage transients that occur in circuits containing inductors when the current changes rapidly (especially when suddenly interrupted). This phenomenon stems from the fundamental characteristic of inductors: the voltage across an inductor is proportional to the rate of change of the current within it, i.e., V = L·(di / dt), where L is the inductance value and di / dt is the rate of change of current. When a switching transistor rapidly disconnects the inductor, the current in the inductor is forced to decrease drastically, resulting in a large di / dt value. According to the above formula, this generates a high-amplitude voltage spike across the inductor. The amplitude of these voltage spikes can reach several times the normal operating voltage of the circuit, sufficient to break down semiconductor devices and cause permanent damage.

[0026] refer to Figure 1 , Figure 1 The circuit principle of a conventional bootstrap charge pump circuit is shown. Figure 1 The bootstrap charge pump circuit shown includes nodes A, B, C, and D.

[0027] exist Figure 1In this circuit, the ninth resistor R9, the fifth switch Q5, the first resistor R1, the first capacitor C1, the first diode D1, the second diode D2, the second capacitor C2, and the second resistor R2 form a bootstrap charge pump circuit. This bootstrap charge pump circuit is used to provide a drive voltage for the back-to-back switch transistors that act as bus switches.

[0028] In addition, the third diode D3 and the third resistor R3 form a pre-charging circuit, which is connected to the charge pump circuit and is used to pre-charge the bootstrap charge pump circuit before the back-to-back switching transistors are turned on.

[0029] The first switch S1 and the second switch S2 are control switches, controlled by the control module 130, used to control the on and off of the back-to-back switching transistors. The back-to-back switching transistors, serving as bus switches, consist of a fourth switching transistor Q4 and a first switching transistor Q1, where both Q4 and Q1 are N-MOS transistors. Inductors L1 and L2 represent large-capacity common-mode or differential-mode inductors that may be connected in series in the bus.

[0030] During the operation of the bootstrap charge pump circuit, assuming the voltage at node C is VPointC, when the control voltage provided by the control voltage source V1 is high, the fifth switch Q5 is turned on, and the left side of the first resistor R1 and the first capacitor C1 (node ​​A) is pulled low, that is, node A is pulled low by the fifth switch Q5. At this time, the voltage VPointC at node C charges the first capacitor C1 through the second diode D2, clamping the voltage from node B to node A to VPointC - VD2 (VD2 is the forward voltage drop of the second diode D2).

[0031] When the control voltage is low, the fifth switch Q5 is off, and the voltage at node A is pulled up to VCC by resistor R1 (VCC is the voltage provided by the voltage source). Since C1 is a capacitor, the voltage difference between node B and node A cannot change abruptly; therefore, the voltage at node B becomes VCC + VPointC - VD2. Since the initial voltage at node D is VCC - VD3 (VD3 is the forward voltage drop of the third diode D3), node B charges the second capacitor C2 through the first diode D1. After the fifth switch Q5 switches multiple times, the voltage at node D becomes VCC + VPointC - VD2 - VD3. Therefore, the voltage across the second capacitor C2 is always the voltage at node D minus the voltage at node C, i.e., VCC - VD2 - VD3.

[0032] The switching drive signals for the first switch S1 and the second switch S2 come from the control module 130, which is an existing chip that generates pulse signals. The first switch S1 acts as a drive switch, using the voltage across the second capacitor C2 as the high-side drive voltage and the floating ground drive. Before the fourth switch Q4 and the first switch Q1 are turned on, the second capacitor C2 is charged to VCC-VD2-VD3 by the third diode D3 and the third resistor R3 as the drive voltage. After the fourth switch Q4 and the first switch Q1 are turned on, the voltage VPointC at node C is clamped to be equal to the bus voltage. Therefore, the voltage VPointD at node D will become: VCC plus the bus voltage minus VD2 and VD3, i.e., VPointC = VCC + bus voltage - VD2 - VD3. When the fourth switch Q4 and the first switch Q1 are turned off, a negative induced voltage spike will be generated at the midpoint between the fourth switch Q4 and the first switch Q1 because the current of the inductor L1 (or inductor L2) is cut off. Because node D is clamped by VCC, node C generates a negative induced voltage spike.

[0033] In practical applications, the back-to-back switching transistors, namely the first switching transistor Q1 and the fourth switching transistor Q4, along with their driving resistors (the eighth resistor R8 and the fourth resistor R4) and discharge resistors (the sixth resistor R6 and the seventh resistor R7), function as input / output switches. When the first switch S1 is open and the second switch S2 is closed, the fourth switching transistor Q4 and the first switching transistor Q1 are turned on; when the first switch S1 is closed and the second switch S2 is open, the fourth switching transistor Q4 and the first switching transistor Q1 are turned off. The first switch S1 and the second switch S2 are controlled by the control module 130.

[0034] The existing bootstrap charge pump circuit has a problem: when the fourth switch Q4 and the first switch Q1 are turned off, the voltage of the second capacitor C2 will be charged by the negative induced voltage spike, causing the voltage VC2 of the second capacitor C2 to increase and be stored as: VCC plus the bus voltage minus VD2 and VD3 plus the energy of the induced voltage spike, i.e., VC2 = VCC + bus voltage - VD2 - VD3 + V (energy of the induced voltage spike). If this action is repeated many times in a short period of time, or if the negative induced voltage spike is very large, the voltage of the second capacitor C2 will increase to an uncontrollable high value, which may damage the drive circuit and related components.

[0035] In switching power supply applications, when large-capacity common-mode or differential-mode inductors L1 and L2 are connected in series in the bus, fast-switching back-to-back switching transistors will generate induced voltage spikes. Due to the characteristics of charge pumps, namely that the voltage across a capacitor cannot change abruptly, these spikes will be stored by the charge pump, causing the charge pump voltage to continuously increase, which may eventually damage the device.

[0036] exist Figure 1In the bootstrap charge pump circuit shown, in addition to the basic components mentioned above, there is also a control voltage source V1, which is used to provide control voltage for the fifth switch Q5, and a ninth resistor R9 is connected between the control voltage source V1 and the base of the fifth switch Q5 for current limiting.

[0037] The entire bootstrap charge pump circuit operates in two phases: charging and discharging. During the charging phase, charge is accumulated through the first capacitor C1 and the second capacitor C2. During the discharging phase, the accumulated charge provides the driving voltage for the back-to-back switching transistors. The charging and discharging process of the bootstrap charge pump circuit can be controlled by switching between high and low voltage levels.

[0038] The main feature of this bootstrap charge pump circuit is that it utilizes the charging and discharging characteristics of a capacitor to boost the input voltage to a higher level, providing sufficient drive voltage for the back-to-back switching transistors. However, when the back-to-back switching transistors switch rapidly and there is a large inductance in the bus, induced voltage spikes can cause abnormal increases in the charge pump voltage, posing a safety hazard.

[0039] To address the aforementioned problems, this application provides a bootstrap charge pump circuit, such as... Figure 2 As shown, the bootstrap charge pump circuit 10 includes a precharge module 110, a charge pump module 120, a control module 130, a bus switch module 140, and a voltage protection module 150. The bootstrap charge pump circuit 10 is externally connected to a voltage source VCC and a bus inductor 20.

[0040] In this embodiment, the pre-charge module 110 is connected to the charge pump module 120 and is configured to charge the charge pump module 120 before the bus is turned on, so that the charge pump module 120 outputs a drive voltage. The pre-charge module 110 obtains electrical energy from the voltage source VCC and transmits the electrical energy to the charge pump module 120 through a certain circuit structure, pre-charging the charge pump module 120 and providing the necessary voltage support for the initial operation of the charge pump module 120.

[0041] The charge pump module 120 is connected to the precharge module 110 and is also connected to the bus switch module 140 and the voltage protection module 150. The main function of the charge pump module 120 is to generate a drive voltage, which is used to control the switching elements in the bus switch module 140. Through a specific circuit topology, the charge pump module 120 utilizes the charging and discharging characteristics of a capacitor to achieve voltage conversion and boosting, thereby providing a suitable drive voltage for the bus switch module 140.

[0042] Control module 130 is configured to output a control signal for controlling the switching state of bus switch module 140. Control module 130 generates control signals with specific waveforms and timings to ensure that bus switch module 140 is turned on or off at the correct time.

[0043] The bus switch module 140 is connected to the charge pump module 120 and the control module 130, and is configured to control the conduction and disconnection of the bus based on the drive voltage and control signal. The bus switch module 140 includes a switching element that controls the bus current path by receiving the drive voltage provided by the charge pump module 120 and the control signal output by the control module 130. When the switching element is on, current can flow through the bus; when the switching element is off, the bus current is interrupted.

[0044] The voltage protection module 150 is connected to the output of the charge pump module 120 and is configured to absorb induced voltage spikes from the bus inductor 20 when the bus is disconnected, and limit the drive voltage within a preset voltage range. The voltage protection module 150 protects against induced voltage spikes generated by the bus inductor 20, preventing abnormal increases in the output voltage of the charge pump module 120 due to the induced voltage spikes, thereby protecting the components in the bootstrap charge pump circuit 10 from damage caused by excessive voltage.

[0045] The bus inductor 20 is connected in series in the bus and can be a common-mode inductor or a differential-mode inductor. When the bus switch module 140 is disconnected, the current in the bus inductor 20 is forced to stop, and due to the energy storage characteristics of the inductor, an induced voltage spike will be generated.

[0046] The operation of the bootstrap charge pump circuit 10 can be described as follows: First, the precharge module 110 charges the charge pump module 120 before the bus is turned on, so that the charge pump module 120 outputs an initial drive voltage; then, the control module 130 outputs a control signal; next, the bus switch module 140 controls the on and off states of the bus according to the drive voltage provided by the charge pump module 120 and the control signal output by the control module 130; when the bus switch module 140 disconnects the bus, the bus inductor 20 will generate an induced voltage spike, and the voltage protection module 150 absorbs the induced voltage spike and limits the drive voltage within a preset voltage range, protecting the bootstrap charge pump circuit 10 from damage by the voltage spike.

[0047] Through the above structure and workflow, the bootstrap charge pump circuit 10 provided in this embodiment solves the problems in the prior art. By introducing the voltage protection module 150, the problem of voltage continuously rising due to the induced voltage spike generated by the inductance when the bus is disconnected is effectively prevented from being stored by the charge pump, avoiding the possibility of damage to the device due to excessive voltage, and improving the safety and reliability of the circuit.

[0048] refer to Figure 3 , Figure 3 The circuit principle of a bootstrap charge pump circuit provided in an embodiment of this application is illustrated. Figure 3 The bootstrap charge pump circuit structure shown is more detailed, illustrating the circuit composition and connection relationships of each functional module.

[0049] like Figure 3 As shown, the bootstrap charge pump circuit includes a precharge module 110, a charge pump module 120, a control module 130, and a voltage protection module 150. The bus switch module 140 includes a drive unit 141 and a switch unit 142.

[0050] In this embodiment, the charge pump module 120 includes a fifth switch Q5, a first resistor R1, a second resistor R2, a ninth resistor R9, a first capacitor C1, a second capacitor C2, a first diode D1, and a second diode D2. The base of the fifth switch Q5 is connected to the first terminal of the ninth resistor R9, and the second terminal of the ninth resistor R9 receives the control voltage provided by the control voltage source V1. The collector of the fifth switch Q5 is connected to the first terminal of the first resistor R1 and the first terminal of the first capacitor C1, and the second terminal of the first resistor R1 is connected to the voltage source VCC. The second terminal of the first capacitor C1 is connected to the anode of the first diode D1 and the cathode of the second diode D2. The cathode of the first diode D1 is connected to the first terminal of the second capacitor C2, and the second terminal of the second capacitor C2 is connected to the anode of the second diode D2 and the first terminal of the second resistor R2. The second terminal of the second resistor R2 and the emitter of the fifth switch Q5 are connected to reference ground.

[0051] The working principle of the charge pump module 120 is as follows: When the control voltage is high, the fifth switch Q5 is turned on, and the left side of the first capacitor C1 is pulled low; when the control voltage is low, the fifth switch Q5 is turned off, and the voltage on the left side of the first capacitor C1 is pulled up to VCC by the first resistor R1. Through the periodic switching of the fifth switch Q5, in conjunction with the charging and discharging process of the first capacitor C1, the first diode D1, the second diode D2, and the second capacitor C2, the voltage conversion and boosting are achieved, ultimately forming a stable driving voltage across the second capacitor C2.

[0052] In this embodiment, the pre-charge module 110 includes a third diode D3 and a third resistor R3. The anode of the third diode D3 is connected to the voltage source VCC, the cathode of the third diode D3 is connected to the first terminal of the third resistor R3, and the second terminal of the third resistor R3 is connected to the output terminal of the charge pump module 120. The function of the pre-charge module 110 is to provide an initial voltage to the second capacitor C2 of the charge pump module 120 before the switching transistor of the bus switch module is turned on, ensuring that the second capacitor C2 is charged to VCC-VD3 (VD3 is the forward voltage drop of the third diode D3), thus providing the necessary voltage basis for the subsequent driving of the switching transistor.

[0053] In this embodiment, the drive unit 141 in the bus switch module 140 includes a first switch S1 and a second switch S2. The control terminal of the first switch S1 receives a control signal, and the first terminal of the first switch S1 is connected to the first output terminal of the charge pump module 120. The second terminal of the first switch S1 is connected to the first terminal of the second switch S2, the second terminal of the eighth resistor R8, and the second terminal of the fourth resistor R4. The control terminal of the second switch S2 receives a control signal, and the second terminal of the second switch S2 is connected to the second output terminal of the charge pump module 120. The function of the drive unit 141 is to generate an appropriate drive signal to control the switching transistor in the switch unit 142 based on the received control signal and the drive voltage provided by the charge pump module 120.

[0054] In this embodiment, the switching unit 142 in the bus switch module 140 includes a first switching transistor Q1, a fourth switching transistor Q4, a fourth resistor R4, a sixth resistor R6, a seventh resistor R7, and an eighth resistor R8. The gate of the first switching transistor Q1 is connected to the first terminal of the fourth resistor R4 and the first terminal of the seventh resistor R7. The drain of the first switching transistor Q1 is connected to the bus inductor (inductor L2). The source of the first switching transistor Q1 is connected to the source of the fourth switching transistor Q4, the second terminal of the seventh resistor R7, and the second terminal of the sixth resistor R6. The gate of the fourth switching transistor Q4 is connected to the first terminal of the sixth resistor R6 and the first terminal of the eighth resistor R8. The drain of the fourth switching transistor Q4 is connected to the bus inductor (inductor L1). The second terminals of the eighth resistor R8 and the fourth resistor R4 are both connected to the output terminal of the drive unit 141.

[0055] The working principle of the drive unit 141 and the switch unit 142 is as follows: When the first switch S1 is closed and the second switch S2 is open, the source of the first switch transistor Q1 and the source of the fourth switch transistor Q4 are connected to the first terminal of the second capacitor C2, and the second terminal of the eighth resistor R8 and the second terminal of the fourth resistor R4 are connected to the second terminal of the second capacitor C2. The gates of the first switch transistor Q1 and the fourth switch transistor Q4 are pulled high, and the first switch transistor Q1 and the fourth switch transistor Q4 are turned on, and the bus is turned on. When the first switch S1 is open and the second switch S2 is closed, the second terminal of the eighth resistor R8 and the second terminal of the fourth resistor R4 are connected to the second terminal of the second capacitor C2, and the source of the first switch transistor Q1 and the source of the fourth switch transistor Q4 are also connected to the second terminal of the second capacitor C2. The gates of the first switch transistor Q1 and the fourth switch transistor Q4 are pulled low, and the first switch transistor Q1 and the fourth switch transistor Q4 are turned off, and the bus is disconnected. The fourth resistor R4, the sixth resistor R6, the seventh resistor R7, and the eighth resistor R8 are used to control the rise and fall rates of the gate voltage and to provide a discharge path when the first switch Q1 and the fourth switch Q4 are turned off.

[0056] In this embodiment, the voltage protection module 150 includes a voltage suppressor D4, which is connected in parallel across the second capacitor C2 of the charge pump module 120.

[0057] In some embodiments of this application, the voltage suppressor D4 is a transient voltage suppressor diode (TVS). When the output voltage of the charge pump module 120 exceeds a preset threshold, the voltage suppressor D4 is turned on to absorb excess energy and clamp the voltage within a safe range. The key function of the voltage protection module 150 is to prevent the induced voltage spike generated by the bus inductance from causing an abnormal increase in the output voltage of the charge pump module 120 when the first switch Q1 and the fourth switch Q4 are turned off.

[0058] The bus inductor is connected in series in the bus and can be a common-mode inductor or a differential-mode inductor. In this embodiment, the bus inductor refers to inductors L1 and L2. When the switch in the switching unit 142 is turned off, the current in the bus inductor is forced to stop, generating an induced voltage spike.

[0059] The entire bootstrap charge pump circuit can be summarized as follows: First, the precharge module 110 precharges the second capacitor C2 of the charge pump module 120 through the third diode D3 and the third resistor R3, providing an initial voltage; then, the charge pump module 120 forms a driving voltage across the second capacitor C2 through the periodic switching of the fifth switch Q5, combined with the charging and discharging process of the capacitor and diode; next, the drive unit 141 of the bus switch module 140 controls the switching state of the switch in the switch unit 142 according to the control signal and the driving voltage provided by the charge pump module 120; when the switch is turned off, the bus inductor generates an induced voltage spike, and the voltage suppressor D4 in the voltage protection module 150 is turned on to absorb the induced voltage spike and prevent the output voltage of the charge pump module 120 from rising abnormally.

[0060] The charge pump module 120 in this embodiment adopts a bootstrap charge pump structure, which increases the voltage through the charging and discharging process of the capacitor. The pre-charge module 110 provides the initial voltage to the charge pump module 120 to ensure normal operation during circuit startup. The bus switch module 140 is divided into a drive unit 141 and a switch unit 142 to achieve precise control of the bus. The voltage protection module 150 uses a voltage suppressor D4 to effectively absorb induced voltage spikes and protect circuit components.

[0061] Compared to existing technologies, the bootstrap charge pump circuit provided in this embodiment effectively solves the problem of continuously rising charge pump voltage caused by induced voltage spikes when the bus is disconnected by introducing a voltage protection module 150. This avoids the possibility of damage to components due to excessive voltage and improves the safety and reliability of the circuit. At the same time, the circuit structure is relatively simple and easy to implement, making it suitable for various switching power supply applications. Especially when a large inductor is connected in series in the bus, it can effectively protect circuit components from damage caused by voltage spikes.

[0062] Based on the bootstrap charge pump circuit provided in the above embodiments, this application also provides an energy storage power supply, which includes the bootstrap charge pump circuit provided in the above embodiments.

[0063] It should be noted that while the preferred embodiments of this utility model are provided in the specification and accompanying drawings, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are not intended to impose additional limitations on the content of this utility model; their purpose is to provide a more thorough and comprehensive understanding of the disclosure of this utility model. Furthermore, the above-described technical features can be combined with each other to form various embodiments not listed above, all of which are considered to be within the scope of this utility model specification. Moreover, those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A bootstrap charge pump circuit, characterized in that, include: Charge pump module; A pre-charge module, connected to the charge pump module, is configured to pre-charge the charge pump module before the bus is turned on, so that the charge pump module outputs a drive voltage; The control module is configured to output control signals; A bus switch module, connected to the charge pump module and the control module, is configured to control the on and off of the bus according to the drive voltage and the control signal; A voltage protection module, connected to the output of the charge pump module, is configured to absorb induced voltage spikes from the bus inductance when the bus is disconnected and limit the drive voltage within a preset voltage range.

2. The circuit according to claim 1, characterized in that, The voltage protection module includes: A voltage suppressor, connected between the first and second output terminals of the charge pump module, is configured to turn on when the driving voltage exceeds a preset voltage threshold, so as to absorb the induced voltage spike and clamp the driving voltage within a preset voltage range.

3. The circuit according to claim 2, characterized in that, The voltage suppressor is a transient voltage suppression diode, which is connected between the first output terminal and the second output terminal of the charge pump module.

4. The circuit according to claim 1, characterized in that, The busbar switch module includes: A drive unit, connected to the control module and the charge pump module, is configured to output a drive signal in response to the drive voltage and the control signal; A switching unit, connected to the driving unit, is configured to control the conduction and disconnection of the bus according to the driving signal.

5. The circuit according to claim 4, characterized in that, The switching unit includes a first switching transistor, a fourth switching transistor, a fourth resistor, a sixth resistor, a seventh resistor, and an eighth resistor; The gate of the first switch is connected to the first end of the fourth resistor and the first end of the seventh resistor. The drain of the first switch is connected to the bus inductor. The source of the first switch is connected to the source of the fourth switch, the second end of the seventh resistor and the second end of the sixth resistor. The gate of the fourth switch is connected to the first end of the sixth resistor and the first end of the eighth resistor. The drain of the fourth switch is connected to the bus inductor. The second end of the eighth resistor and the second end of the fourth resistor are both connected to the output terminal of the drive unit.

6. The circuit according to claim 5, characterized in that, The drive unit includes a first switch and a second switch; The control terminal of the first switch is connected to the control module, the first terminal of the first switch is connected to the first output terminal of the charge pump module, the second terminal of the first switch is connected to the first terminal of the second switch, the second terminal of the eighth resistor and the second terminal of the fourth resistor, the control terminal of the second switch is connected to the control module, and the second terminal of the second switch is connected to the second output terminal of the charge pump module. Specifically, when the first switch is closed and the second switch is open, the first switch transistor and the fourth switch transistor are turned on; when the first switch is open and the second switch is closed, the first switch transistor and the fourth switch transistor are turned off.

7. The circuit according to claim 1, characterized in that, The charge pump module includes a fifth switch, a first resistor, a second resistor, a ninth resistor, a first capacitor, a second capacitor, a first diode, and a second diode; The base of the fifth switch is connected to the first end of the ninth resistor. The second end of the ninth resistor receives a control voltage. The collector of the fifth switch is connected to the first end of the first resistor and the first end of the first capacitor. The second end of the first resistor is connected to a voltage source. The second end of the first capacitor is connected to the anode of the first diode and the cathode of the second diode. The cathode of the first diode is connected to the first end of the second capacitor. The second end of the second capacitor is connected to the anode of the second diode and the first end of the second resistor. The second end of the second resistor and the emitter of the fifth switch are connected to a reference ground.

8. The circuit according to claim 1, characterized in that, The precharge module includes a third diode and a third resistor; The anode of the third diode is connected to a voltage source, the cathode of the third diode is connected to the first end of the third resistor, and the second end of the third resistor is connected to the output end of the charge pump module.

9. The circuit according to claim 1, characterized in that, The bus inductor is connected in series in the bus, and the bus inductor includes at least one of common-mode inductor and differential-mode inductor.

10. An energy storage power source, characterized in that, include: The bootstrap charge pump circuit as described in any one of claims 1-9.

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