A negative voltage off type driving circuit and an energy storage power supply

Abstract

The utility model discloses a kind of negative pressure off type drive circuit and energy storage power supply. The circuit includes: level input module, for receiving control signal and providing different level according to control signal level;Push-pull drive module is connected with power switch module, when control signal is high level, output positive pressure drive signal and drive power switch module conduction, and provide zero level for isolated energy storage module;Isolated energy storage module is connected between level input module and push-pull drive module, when control signal is low level, output negative pressure level signal;Push-pull drive module responds negative pressure level signal and outputs negative pressure drive signal to power switch module. By the above-mentioned mode, the utility model embodiment can be extracted away gate charge by negative pressure drive fast, effectively avoid the mis-conduction phenomenon caused by miller capacitance, accelerate power switch off speed, simultaneously realize the electrical isolation of control side and drive side, improve circuit reliability and anti-interference ability.

Description

Technical Field

[0001] This utility model relates to the field of switch drive, and in particular to a negative voltage turn-off type drive circuit and energy storage power supply. Background Technology

[0002] In power electronic circuits, power switching devices such as MOSFETs are widely used in various power conversion systems, including switching power supplies, DC-DC converters, motor drive control, photovoltaic inverters, and UPS uninterruptible power supplies, due to their advantages such as fast switching speed, low on-resistance, low drive power, and simple control. To achieve reliable turn-on and fast turn-off of power switches, a dedicated gate drive circuit needs to be designed for precise control. The performance of the drive circuit directly affects the efficiency and reliability of the entire power system.

[0003] In existing technologies, conventional PWM drive circuits typically use 0V as the reference ground level and drive power switching devices by outputting high and low level signals through the control circuit. The specific working process is as follows: when the PWM control signal is high, the drive circuit applies a positive voltage (usually 12V or 15V) to the gate of the power switch to turn it on; when the PWM control signal is low, the drive circuit pulls the gate voltage to 0V (ground level) to turn it off.

[0004] However, this traditional zero-level turn-off drive method has obvious technical defects: First, when turning off, only the gate voltage is reduced to 0V, which lacks sufficient negative driving force to quickly remove the charge accumulated on the gate, resulting in a slow turn-off speed of the power switch, prolonging the switching loss time and reducing circuit efficiency; Second, MOSFETs have the Miller capacitance effect during fast switching. When the drain-source voltage changes rapidly, it will couple to the gate through the Miller capacitance between the gate and drain, causing unexpected fluctuations in the gate voltage. This can easily cause false turn-on or false turn-off of the power switch, seriously affecting the reliability and stability of the circuit operation; Finally, in high switching frequency applications, the above-mentioned problems of slow turn-off speed and weak anti-interference ability will be more prominent, limiting the improvement of the circuit's operating frequency and performance optimization. Utility Model Content

[0005] The main technical problem solved by this utility model embodiment is to provide a negative voltage shutdown type drive circuit and energy storage power supply, which can solve at least some of the defects of existing power switch drive circuits.

[0006] In a first aspect, this utility model provides a negative voltage turn-off type drive circuit, comprising: a level input module for receiving a control signal, providing a first level to an isolated energy storage module when the control signal is high, and providing a second level to the isolated energy storage module when the control signal is low; the first level being higher than the second level; a push-pull drive module connected to a power switch module for receiving the control signal, outputting a positive voltage drive signal to drive the power switch module to conduct when the control signal is high, and providing a zero level to the isolated energy storage module; an isolated energy storage module, the second terminal of which is connected to the level input module, and the first terminal of which is connected to the push-pull drive module, for outputting a negative voltage level signal to the push-pull drive module in response to a transition from the first level to the second level when the control signal is low; the push-pull drive module is further configured to output a negative voltage drive signal to the power switch module in response to the negative voltage level signal when the control signal is low.

[0007] Optionally, the push-pull drive module includes: a switch push-pull unit, configured to output a first drive signal in response to a high-level control signal; and to stop outputting the first drive signal in response to a low-level control signal; a switch level unit, connected to the switch push-pull unit, configured to provide the zero level to the isolated energy storage module in response to the first drive signal; and a switch drive unit, connected to the switch push-pull unit and the power switch module, configured to generate the positive voltage drive signal in response to the first drive signal; and to output the negative voltage drive signal to the power switch module in response to the negative voltage level signal.

[0008] Optionally, the push-pull switch unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first switch transistor, and a second switch transistor; a first terminal of the first resistor is connected to the control signal, a second terminal of the first resistor is connected to the first terminal of the second resistor and the base of the first switch transistor, the collector of the first switch transistor is connected to the second terminal of the third resistor, the first terminal of the third resistor is connected to the first terminal of the fourth resistor and the base of the second switch transistor, and the emitter of the second switch transistor and the second terminal of the fourth resistor are connected to the power supply voltage; the collector of the second switch transistor is connected to the first terminal of the fifth resistor, the signal input terminal of the switch level unit, and the signal input terminal of the switch drive unit, the second terminal of the fifth resistor is connected to the first terminal of the isolated energy storage module, and the second terminal of the second resistor and the emitter of the first switch transistor are connected to reference ground.

[0009] Optionally, the switching level unit includes a seventh resistor, an eighth resistor, a twelfth resistor, and a fifth switching transistor; the first end of the seventh resistor is connected to the signal output terminal of the push-pull switching unit, the second end of the seventh resistor is connected to the first end of the twelfth resistor and the first end of the eighth resistor, the second end of the twelfth resistor is connected to the base of the fifth switching transistor, the collector of the fifth switching transistor is connected to the first terminal of the isolated energy storage module, and the second end of the eighth resistor and the emitter of the fifth switching transistor are connected to reference ground.

[0010] Optionally, the switch driving unit includes a sixth resistor, a third switch, and a fourth switch; the base of the third switch is connected to the base of the fourth switch and the signal output terminal of the push-pull switch unit, the collector of the third switch is connected to the power supply voltage, the emitter of the third switch is connected to the emitter of the fourth switch and the first terminal of the sixth resistor, the collector of the fourth switch is connected to the first terminal of the isolated energy storage module, and the second terminal of the sixth resistor is connected to the power switch module.

[0011] Optionally, the level input module includes a first diode, a ninth resistor, a tenth resistor, an eleventh resistor, a sixth switch, and a seventh switch; the second terminal of the ninth resistor is connected to the control signal, the first terminal of the ninth resistor is connected to the base of the seventh switch, the collector of the seventh switch is connected to the base of the sixth switch and the second terminal of the tenth resistor, and the first terminal of the tenth resistor is connected to the power supply voltage; the collector of the sixth switch is connected to the second terminal of the isolated energy storage module and the cathode of the first diode, the anode of the first diode is connected to the second terminal of the eleventh resistor, the first terminal of the eleventh resistor is connected to the power supply voltage, and the emitters of the sixth switch and the seventh switch are connected to reference ground.

[0012] Optionally, the isolated energy storage module includes a first capacitor and a thirteenth resistor; the first end of the first capacitor is connected to the level output terminal of the push-pull drive module, the second end of the first capacitor is connected to the level output terminal of the level input module, and the thirteenth resistor is connected in parallel across the first capacitor.

[0013] Optionally, the negative pressure shutdown type drive circuit further includes: a signal input module, together with the level input module and the push-pull drive module, for receiving pulse width modulation signals and outputting the control signals.

[0014] Optionally, the signal input module includes a fifteenth resistor and an AND gate; the first input terminal of the AND gate is connected to the pulse width modulation signal, the second terminal of the AND gate is connected to the first terminal of the fifteenth resistor, and the second terminal of the fifteenth resistor is connected to the power supply voltage.

[0015] Secondly, the present invention provides an energy storage power supply, including: a negative voltage shutdown type drive circuit as described in the first aspect.

[0016] The beneficial effects of this utility model embodiment are as follows: Unlike the prior art, this utility model embodiment outputs a negative voltage drive signal when the control signal transitions from a high level to a low level through the isolation energy storage module. The push-pull drive module applies this negative voltage to the gate of the power switch module, which can quickly remove the gate charge, effectively avoid the false turn-on phenomenon caused by Miller capacitance, and speed up the turn-off speed of the power switch. At the same time, the isolation energy storage module realizes electrical isolation between the control side and the drive side, improving the reliability and anti-interference capability of the circuit. Attached Figure Description

[0017] 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.

[0018] Figure 1 This is a schematic diagram of the structure of a negative pressure shut-off drive circuit provided by an embodiment of the present invention; Figure 2 This is a schematic diagram of another negative pressure shut-off type drive circuit provided by this utility model embodiment; Figure 3 This is a schematic diagram of the structure of a push-pull drive module provided by an embodiment of the present invention; Figure 4 This is a circuit diagram of a negative pressure shut-off type drive circuit provided by an embodiment of this utility model. 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] In some embodiments of this application, such as Figure 1 As shown, a negative voltage turn-off type drive circuit 10 is provided. The negative voltage turn-off type drive circuit 10 is used to drive the power switch module 20 to realize reliable turn-on and fast turn-off of the power switch module 20.

[0022] Specifically, refer to Figure 1 The negative voltage shutdown type drive circuit 10 includes a level input module 110. The level input module 110 is used to receive control signals. The control signals are digital signals used to control the switching state of the power switch module 20, and the control signals have two logic levels: a high level state and a low level state.

[0023] In some embodiments of this application, the level input module 110 provides a first level to the isolated energy storage module 130 when the control signal is high. Specifically, when the level input module 110 receives a high-level control signal, the level input module 110 outputs the first level to the isolated energy storage module 130. By way of example and not limitation, the first level can be a positive voltage value, such as a voltage value equal to or close to the supply voltage.

[0024] Furthermore, the level input module 110 provides a second level to the isolated energy storage module 130 when the control signal is low. When the level input module 110 receives a low-level control signal, it outputs the second level to the isolated energy storage module 130. By way of example and not limitation, the second level can be zero or a lower voltage value.

[0025] In some embodiments of this application, the first level is higher than the second level. It is easy to understand that the level input module 110 outputs different level values ​​according to the logic state of the control signal. The first level corresponds to a high-level control signal state, and the second level corresponds to a low-level control signal state, with a voltage difference between the two.

[0026] In some embodiments of this application, such as Figure 1 As shown, the negative pressure shutdown type drive circuit 10 also includes a push-pull drive module 120. The push-pull drive module 120 is connected to the power switch module 20. Specifically, the drive output terminal of the push-pull drive module 120 is electrically connected to the control terminal of the power switch module 20, and is used to provide a drive signal to the power switch module 20.

[0027] The push-pull drive module 120 is used to receive control signals. Both the push-pull drive module 120 and the level input module 110 receive the same control signal and perform corresponding drive operations according to the state of the control signal.

[0028] In some embodiments of this application, the push-pull drive module 120 outputs a positive voltage drive signal to drive the power switch module 20 to conduct when the control signal is high. Specifically, when the control signal is high, the push-pull drive module 120 generates a positive voltage drive signal and applies it to the control terminal of the power switch module 20, causing the power switch module 20 to enter the conduction state.

[0029] As an example and not a limitation, the positive drive signal is a positive voltage signal higher than the reference ground. When the power switch module 20 is a MOSFET device, the positive drive signal is applied between the gate and the source. When the gate-source voltage exceeds the turn-on threshold voltage, the MOSFET turns on, and a low-impedance conductive channel is formed between the drain and the source.

[0030] Furthermore, when the control signal is high, the push-pull drive module 120 also provides a zero level to the isolated energy storage module 130. It is easy to understand that while outputting a positive voltage drive signal, the push-pull drive module 120 provides a zero level at the port connected to the isolated energy storage module 130. The zero level is the reference ground potential or a low voltage close to the reference ground.

[0031] In some embodiments of this application, such as Figure 1 As shown, the negative voltage shutdown type drive circuit 10 also includes an isolation energy storage module 130. The second terminal of the isolation energy storage module 130 is connected to the level input module 110. Specifically, the isolation energy storage module 130 has a first terminal and a second terminal, and the second terminal is electrically connected to the output terminal of the level input module 110 to receive the level signal from the level input module 110.

[0032] Furthermore, the first end of the isolated energy storage module 130 is connected to the push-pull drive module 120. The first end of the isolated energy storage module 130 is electrically connected to the push-pull drive module 120, and the isolated energy storage module 130 is located between the level input module 110 and the push-pull drive module 120.

[0033] In some embodiments of this application, the isolated energy storage module 130 is used to output a negative voltage level signal to the push-pull drive module 120 in response to a transition from a first level to a second level when the control signal is low. Specifically, when the control signal transitions from a high level to a low level, the level provided by the level input module 110 transitions from the first level to the second level accordingly.

[0034] The isolated energy storage module 130 responds to a level transition by outputting a negative voltage level signal at its first terminal. By way of example and not limitation, during a high-level control signal, the level input module 110 provides a first level to the second terminal of the isolated energy storage module 130, and the push-pull drive module 120 provides a zero level to the first terminal of the isolated energy storage module 130, thus storing energy internally. When the control signal transitions to a low level, the level provided by the level input module 110 decreases from the first level to the second level, causing the potential at the second terminal of the isolated energy storage module 130 to drop. Due to the energy storage characteristics of the isolated energy storage module 130, the potential at the first terminal drops accordingly, thereby generating a negative voltage level signal at the first terminal that is lower than the reference ground.

[0035] Furthermore, the isolated energy storage module 130 outputs a negative voltage level signal to the push-pull drive module 120. The push-pull drive module 120 receives the negative voltage level signal from the first terminal of the isolated energy storage module 130.

[0036] In some embodiments of this application, the push-pull drive module 120 is further configured to output a negative voltage drive signal to the power switch module 20 in response to a negative voltage level signal when the control signal is low. Specifically, when the control signal is low, the push-pull drive module 120 receives a negative voltage level signal from the isolated energy storage module 130, generates a negative voltage drive signal based on the negative voltage level signal, and applies the negative voltage drive signal to the control terminal of the power switch module 20.

[0037] It is easy to understand that the negative voltage drive signal is a negative voltage signal lower than the reference ground potential. When the negative voltage drive signal is applied to the control terminal of the power switch module 20, it can quickly remove the accumulated charge at the control terminal, causing the power switch module 20 to turn off rapidly.

[0038] As an example and not a limitation, when the power switching module 20 is a MOSFET device, a negative voltage drive signal is applied between the gate and the source, forming a negative gate-source voltage. The negative gate-source voltage can quickly remove the gate charge, accelerate the discharge process of the gate-source capacitance, and at the same time provide sufficient negative drive force to resist the gate voltage fluctuations caused by the Miller capacitance effect, ensuring reliable MOSFET turn-off and avoiding false turn-on.

[0039] In some embodiments of this application, when the control signal is high, the level input module 110 provides a first level to the second terminal of the isolated energy storage module 130, and the push-pull drive module 120 provides a zero level to the first terminal of the isolated energy storage module 130. Simultaneously, the push-pull drive module 120 outputs a positive voltage drive signal to the power switch module 20, causing the power switch module 20 to conduct. During the high-level period, a potential difference exists between the second and first terminals of the isolated energy storage module 130, and energy is stored within the isolated energy storage module 130 to prepare for the subsequent generation of a negative voltage.

[0040] Furthermore, when the control signal transitions from a high level to a low level, the level provided by the level input module 110 transitions from a first level to a second level, and the potential at the second terminal of the isolation energy storage module 130 decreases. As an example and not a limitation, due to the energy storage characteristics of the isolation energy storage module 130, the potential at the first terminal cannot instantaneously follow the change at the second terminal; instead, it maintains its original potential relationship relative to the second terminal. Therefore, when the potential at the second terminal decreases, the potential at the first terminal also decreases accordingly, thereby generating a negative voltage level signal at the first terminal that is lower than the reference ground.

[0041] In some embodiments of this application, the push-pull drive module 120, in response to a negative voltage level signal, converts or transmits the negative voltage level signal into a negative voltage drive signal, which is then applied to the control terminal of the power switch module 20. The negative voltage drive signal quickly removes the charge from the control terminal of the power switch module 20, causing the power switch module 20 to turn off rapidly.

[0042] In some embodiments of this application, the isolated energy storage module 130 generates a negative voltage level signal through a charging and discharging process. The operation of the isolated energy storage module 130 includes a charging stage and a discharging stage, which correspond to the high-level state and low-level transition process of the control signal, respectively.

[0043] In some embodiments of this application, when the control signal is high, the isolated energy storage module 130 enters the charging stage. Specifically, the level input module 110 provides a first level to the second terminal of the isolated energy storage module 130, and the push-pull drive module 120 provides a zero level to the first terminal of the isolated energy storage module 130.

[0044] It is easy to understand that a potential difference is formed between the second terminal and the first terminal of the isolated energy storage module 130. As an example and not a limitation, when the first level is a positive voltage value (e.g., equal to the supply voltage VCC) and the zero level is the reference ground potential (0V), the potential difference between the two terminals of the isolated energy storage module 130 is equal to the value of the first level.

[0045] Furthermore, under the influence of the potential difference, energy begins to be stored inside the isolated energy storage module 130. Specifically, charge flows from the second end to the first end and accumulates inside the isolated energy storage module 130, forming a stable charge distribution state. It is easy to understand that the amount of energy stored inside the isolated energy storage module 130 is directly proportional to the potential difference between the two ends; the greater the potential difference, the more energy is stored.

[0046] In some embodiments of this application, the charging process continues until the isolated energy storage module 130 reaches a stable charging state. By way of example and not limitation, in the initial stage of charging, the charging current is relatively large because the potential difference between the two ends of the isolated energy storage module 130 has just been established; as the charging process proceeds, the energy stored inside the isolated energy storage module 130 gradually increases, and the charging current gradually decreases; when the isolated energy storage module 130 is fully charged, the charging current approaches zero, and the potential difference between the two ends remains stable.

[0047] Furthermore, during the entire high-level period, the isolated energy storage module 130 remains in a charging state, maintaining stable energy storage internally. It is easy to understand that as long as the control signal remains high, the level input module 110 continuously provides the first level to the second terminal, and the push-pull drive module 120 continuously provides the zero level to the first terminal, the potential difference between the two ends of the isolated energy storage module 130 is maintained, and the stored energy will not dissipate.

[0048] In some embodiments of this application, when the control signal transitions from a high level to a low level, the isolated energy storage module 130 enters the discharge phase and generates a negative voltage level signal. Specifically, the level input module 110 responds to the transition of the control signal by changing the level provided to the second terminal of the isolated energy storage module 130 from a first level to a second level.

[0049] It is easy to understand that the potential at the second terminal changes abruptly, dropping from a higher first level to a lower second level. As an example, and not a limitation, if the first level is the supply voltage VCC and the second level is the reference ground potential (0V), then the potential at the second terminal drops abruptly from VCC to 0V.

[0050] In some embodiments of this application, because the isolated energy storage module 130 has energy storage characteristics, the potential at the first end cannot instantaneously follow the potential change at the second end. Specifically, the energy stored inside the isolated energy storage module 130 maintains the original potential relationship between the two ends. When the potential at the second end decreases, the potential at the first end is forced to decrease accordingly to maintain the instantaneous balance of the internal energy state.

[0051] Furthermore, the magnitude of the potential drop at the first terminal is the same as or close to the magnitude of the potential change at the second terminal. It's easy to understand that if the potential at the second terminal drops by ΔV, the potential at the first terminal will also drop by ΔV accordingly. As an example, and not a limitation, in the charging state, the potential at the second terminal is at the first level VCC, and the potential at the first terminal is at zero level 0V; when the potential at the second terminal suddenly drops to the second level 0V, the drop is VCC, and the potential at the first terminal will also drop by VCC accordingly, from 0V to -VCC.

[0052] In some embodiments of this application, the potential at the first terminal drops to a negative value below the reference ground, thereby generating a negative voltage level signal. Specifically, the amplitude of the negative voltage level signal depends on the magnitude of the potential change at the second terminal, i.e., the difference between the first level and the second level. By way of example and not limitation, if the difference between the first level and the second level is VCC, then the amplitude of the generated negative voltage level signal is approximately -VCC.

[0053] Furthermore, the negative voltage level signal is output from the first terminal of the isolation energy storage module 130 to the push-pull drive module 120. It is easy to understand that after receiving the negative voltage level signal, the push-pull drive module 120 converts or transmits it as a negative voltage drive signal and applies it to the control terminal of the power switch module 20.

[0054] In some embodiments of this application, the duration of the negative voltage level signal depends on the discharge characteristics of the isolation energy storage module 130. Specifically, after the negative voltage level signal is generated, the energy stored inside the isolation energy storage module 130 begins to be released, providing a turn-off current to the control terminal of the power switch module 20 through the push-pull drive module 120, thereby removing the accumulated charge from the control terminal.

[0055] As the discharge process proceeds, the energy stored inside the isolation energy storage module 130 gradually decreases, and the amplitude of the negative voltage level signal may gradually decay. As an example and not a limitation, the negative voltage amplitude is the largest at the beginning of the discharge, providing the strongest shutdown driving force; as time goes on, the negative voltage amplitude gradually decreases, but still remains a negative value below the reference ground, continuously providing the shutdown driving force.

[0056] Furthermore, the energy stored in the isolation energy storage module 130 is sufficient to sustain the power switch module 20 for the time required to reliably turn off. Specifically, by rationally designing the energy storage capacity of the isolation energy storage module 130, sufficient negative pressure driving force is ensured to be provided throughout the entire turn-off process until the power switch module 20 is completely turned off.

[0057] Compared to the traditional zero-level turn-off method, the negative voltage turn-off method has significant advantages. The traditional method only reduces the control terminal voltage to zero level, lacking the ability to actively remove charge, resulting in a slow turn-off speed; while the negative voltage drive signal provides a negative voltage, which can actively and quickly remove the charge from the control terminal, significantly accelerating the turn-off speed and reducing switching losses.

[0058] Furthermore, the negative voltage drive signal can effectively resist the Miller capacitance effect. As an example, and not a limitation, during the power switch module 20's turn-off process, the drain-source voltage rises rapidly and couples to the gate through the Miller capacitance, potentially causing an unexpected rise in the gate voltage. The negative voltage drive signal provides a strong negative clamping effect, suppressing gate voltage fluctuations caused by the Miller capacitance, preventing the power switch module 20 from being mistakenly turned on, and improving the reliability of circuit operation.

[0059] In some embodiments of this application, reference is made to Figure 2 The negative voltage shutdown type drive circuit 10 also includes a signal input module 140. The signal input module 140 is connected to the level input module 110 and the push-pull drive module 120. Specifically, the output terminal of the signal input module 140 is electrically connected to the input terminal of the level input module 110 and the signal input terminal of the push-pull drive module 120, respectively, to provide control signals to both.

[0060] Furthermore, the signal input module 140 is used to receive pulse width modulation (PWM) signals. It is easy to understand that the PWM signal is a periodic pulse signal generated by an external control system. By adjusting the duty cycle of the pulses, the on-time ratio of the power switch module 20 is controlled, thereby regulating the power transmission.

[0061] In some embodiments of this application, the pulse width modulation signal has specific voltage amplitude and frequency characteristics. By way of example and not limitation, the high-level amplitude of the pulse width modulation signal can be 3.3V, 5V or other standard logic levels, and the low-level amplitude can be 0V; the frequency range can be from several kilohertz to several hundred kilohertz or even higher, and the specific value is determined according to the application requirements.

[0062] Furthermore, the signal input module 140 is used to output control signals. Specifically, the signal input module 140 processes the received pulse width modulation signal to generate control signals suitable for driving the level input module 110 and the push-pull drive module 120. It is easy to understand that the control signals maintain the same or related logic states and timing relationships as the pulse width modulation signals.

[0063] In some embodiments of this application, the signal input module 140 serves as a signal interface and signal conditioning mechanism. Specifically, the pulse width modulation signal generated by the external control system may have problems such as voltage amplitude mismatch, poor signal quality, and excessive interference noise. The signal input module 140 performs necessary processing on the input pulse width modulation signal to make it meet the requirements of the subsequent circuits.

[0064] The signal input module 140 can perform various signal processing functions. By way of example and not limitation, the signal input module 140 can perform level conversion, converting the input pulse width modulation signal level to the level required by the level input module 110 and the push-pull drive module 120; it can perform signal shaping, eliminating glitches and noise in the pulse width modulation signal and improving the edge quality of the signal; and it can perform signal buffering, providing sufficient drive capability to ensure reliable driving of subsequent modules.

[0065] In some embodiments of this application, the signal input module 140 can also implement signal logic processing functions. Specifically, the signal input module 140 can perform logical operations on the input pulse width modulation signal, such as AND, OR, NOT, and other logical operations, to generate control signals according to specific logical conditions. It is easy to understand that through logic processing, more complex control strategies can be implemented, such as enable control, fault protection, interlock control, etc.

[0066] Furthermore, the signal input module 140 can receive multiple input signals and generate control signals based on the logical relationship between the multiple input signals. By way of example and not limitation, the signal input module 140 can simultaneously receive a pulse width modulation signal and an enable signal. It only outputs a high-level control signal when the enable signal is valid and the pulse width modulation signal is high. If the enable signal is invalid, it outputs a low-level control signal regardless of the state of the pulse width modulation signal, thereby enabling control of the drive circuit.

[0067] Specifically, when the external control system needs to turn on the power switch module 20, it inputs a high-level pulse width modulation signal to the signal input module 140. The signal input module 140 receives and processes the pulse width modulation signal, and outputs a high-level control signal to the level input module 110 and the push-pull drive module 120.

[0068] Furthermore, after receiving a high-level control signal, the level input module 110 provides a first level to the second terminal of the isolated energy storage module 130, and the isolated energy storage module 130 enters the charging stage. At the same time, after receiving a high-level control signal, the push-pull drive module 120 provides a zero level to the first terminal of the isolated energy storage module 130 and outputs a positive voltage drive signal to the power switch module 20, turning on the power switch module 20.

[0069] During the high-level control signal period, the isolated energy storage module 130 is continuously charged and stores energy; the power switch module 20 remains in the on state, and the power current flows through the power switch module 20.

[0070] In some embodiments of this application, when the external control system needs to turn off the power switch module 20, a low-level pulse width modulation signal is input to the signal input module 140. The signal input module 140 receives and processes the pulse width modulation signal, and outputs a low-level control signal to the level input module 110 and the push-pull drive module 120.

[0071] Specifically, after receiving a low-level control signal, the level input module 110 changes the level provided to the second terminal of the isolated energy storage module 130 from the first level to the second level. In response to the level change, the isolated energy storage module 130 generates a negative voltage level signal at its first terminal and outputs it to the push-pull drive module 120.

[0072] Furthermore, after receiving the low-level control signal and the negative voltage level signal, the push-pull drive module 120 responds to the negative voltage level signal by outputting a negative voltage drive signal to the power switch module 20, which quickly removes the charge from the control terminal of the power switch module 20, causing the power switch module 20 to turn off rapidly.

[0073] In some embodiments of this application, the signal input module 140 also serves as a timing coordinator. Specifically, the level input module 110 and the push-pull drive module 120 need to receive control signals synchronously to ensure that the charging and discharging processes of the isolated energy storage module 130 are precisely coordinated with the turn-on and turn-off processes of the power switch module 20.

[0074] It is easy to understand that if the level input module 110 and the push-pull drive module 120 receive the control signal at different times, it may cause a mismatch between the charging and discharging timing of the isolated energy storage module 130 and the output timing of the drive signal, affecting the negative voltage generation effect. As an example and not a limitation, if the push-pull drive module 120 receives the low-level control signal earlier while the level input module 110 receives it later, then the push-pull drive module 120 will have already started the shutdown operation before the isolated energy storage module 130 is ready to generate negative voltage, and will not be able to obtain the negative voltage driving capability.

[0075] In some embodiments of this application, the signal input module 140 ensures that the level input module 110 and the push-pull drive module 120 simultaneously receive the control signal indicating a state change through unified signal processing and synchronized output. Specifically, after receiving a level transition of the pulse width modulation signal, the signal input module 140 outputs the transitioned control signal to the level input module 110 and the push-pull drive module 120 at the same time or within a very short time difference, ensuring timing synchronization.

[0076] Furthermore, the signal input module 140 can optimize the edges of the control signal. By way of example and not limitation, the signal input module 140 can ensure that the rising and falling edges of the control signal have sufficiently steep slopes, reduce edge transition time, and enable the level input module 110 and the push-pull drive module 120 to respond quickly to changes in the control signal, thereby improving the switching speed of the overall circuit.

[0077] In some embodiments of this application, the signal input module 140 may also have an input protection function. Specifically, the externally input pulse width modulation signal may be subject to various interferences, such as electrostatic discharge, voltage spikes, reverse voltage, etc. The signal input module 140 may be equipped with a protection circuit to prevent abnormal input signals from damaging subsequent circuits.

[0078] It is easy to understand that the signal input module 140 can include protective devices such as current limiting elements, clamping elements, and filtering elements. As an example and not a limitation, the signal input module 140 can be equipped with resistor current limiting to prevent excessive input current; it can be equipped with diode clamping to limit the input voltage within a safe range; and it can be equipped with filter capacitors to filter out high-frequency noise in the input signal.

[0079] Furthermore, the signal input module 140 can have fault detection and processing functions. Specifically, the signal input module 140 can detect whether the input pulse width modulation signal is abnormal, such as the frequency exceeding the normal range, the duty cycle being abnormal, or the signal being lost. When an abnormality is detected, the signal input module 140 can output a safety control signal, such as continuously outputting a low-level control signal to keep the power switch module 20 in the off state and prevent the power circuit from running out of control.

[0080] In some embodiments of this application, reference is made to Figure 3 The push-pull drive module 120 includes a switch push-pull unit 121. The switch push-pull unit 121 is the signal processing core of the push-pull drive module 120, responsible for receiving control signals and generating internal drive signals.

[0081] In some embodiments of this application, the push-pull switch unit 121 is used to turn on in response to a high-level control signal. Specifically, when the push-pull switch unit 121 receives a high-level control signal, the switching device or circuit inside the push-pull switch unit 121 enters the on state, establishing a signal transmission channel.

[0082] Furthermore, the push-pull unit 121 outputs a first drive signal when it is in the ON state. The first drive signal is an internal control signal generated by the push-pull unit 121, used to drive other units within the push-pull drive module 120. By way of example and not limitation, the first drive signal can be a high-level signal, the voltage amplitude of which is determined by the circuit characteristics of the push-pull unit 121.

[0083] In some embodiments of this application, the push-pull switch unit 121 is also used to turn off in response to a low-level control signal. Specifically, when the push-pull switch unit 121 receives a low-level control signal, the switching device or circuit inside the push-pull switch unit 121 enters the off state, cutting off the signal transmission channel.

[0084] Furthermore, the push-pull switch unit 121 stops outputting the first drive signal in the off state. When the control signal is low, the push-pull switch unit 121 no longer generates or outputs the first drive signal, causing subsequent units to lose their drive source. By way of example and not limitation, the first drive signal can become low or zero, or the output terminal can present a high impedance state.

[0085] In some embodiments of this application, such as Figure 3 As shown, the push-pull drive module 120 also includes a switching level unit 123. The switching level unit 123 is connected to the push-pull switch unit 121. Specifically, the signal input terminal of the switching level unit 123 is electrically connected to the signal output terminal of the push-pull switch unit 121, and is used to receive the first drive signal.

[0086] Furthermore, the switching level unit 123 is used to turn on in response to the first drive signal. When the switching level unit 123 receives the first drive signal, the switching device or circuit inside the switching level unit 123 is driven into the conducting state, establishing a current path from the first terminal of the isolated energy storage module 130 to the reference ground.

[0087] In some embodiments of this application, the switching level unit 123 is used to provide a zero level to the isolated energy storage module 130. Specifically, when the switching level unit 123 is turned on, the first terminal of the isolated energy storage module 130 is connected to the reference ground through the switching level unit 123, so that the potential of the first terminal is clamped at a zero level or close to a zero level.

[0088] Zero level is the reference ground potential, typically defined as 0V. Through the conduction of the switching level unit 123, the first terminal of the isolated energy storage module 130 forms a low-impedance connection with the reference ground, ensuring that the potential of the first terminal remains stable at zero level. As an example, and not a limitation, during the period when the control signal is high, the push-pull switching unit 121 continuously outputs the first drive signal, the switching level unit 123 remains continuously on, and the first terminal of the isolated energy storage module 130 continuously maintains a zero level, forming a stable potential difference with the first level of the second terminal, thus realizing the charging process.

[0089] Furthermore, when the push-pull switch unit 121 stops outputting the first drive signal, the level switch unit 123 loses its drive source and turns off. Specifically, after the control signal becomes low, the push-pull switch unit 121 stops outputting the first drive signal, and the level switch unit 123 enters the off state, cutting off the connection between the first terminal of the isolated energy storage module 130 and the reference ground. The turn-off of the level switch unit 123 means that the first terminal of the isolated energy storage module 130 is no longer clamped to zero level, allowing the potential of the first terminal to change freely, creating conditions for generating a negative voltage level signal.

[0090] In some embodiments of this application, such as Figure 3 As shown, the push-pull drive module 120 also includes a switch drive unit 122. The switch drive unit 122 is connected to the push-pull switch unit 121 and the power switch module 20. Specifically, the signal input terminal of the switch drive unit 122 is electrically connected to the signal output terminal of the push-pull switch unit 121, and the drive output terminal of the switch drive unit 122 is electrically connected to the control terminal of the power switch module 20.

[0091] In some embodiments of this application, the switch driving unit 122 is used to generate a positive pressure driving signal in response to a first driving signal. Specifically, when the switch driving unit 122 receives the first driving signal output by the switch push-pull unit 121, the internal circuit of the switch driving unit 122 operates, generates a positive pressure driving signal, and outputs it to the power switch module 20.

[0092] It is easy to understand that the positive voltage drive signal is a positive voltage signal higher than the reference ground, used to drive the power switch module 20 to turn on. As an example and not a limitation, when the power switch module 20 is an N-channel MOSFET, the positive voltage drive signal is applied between the gate and the source. When the gate-source voltage exceeds the threshold voltage, the MOSFET turns on, and a conductive channel is formed between the drain and the source, allowing power current to flow.

[0093] Furthermore, the amplitude of the positive voltage drive signal generated by the switch drive unit 122 is sufficient to ensure that the power switch module 20 is reliably turned on. Specifically, the voltage value of the positive voltage drive signal should be significantly higher than the turn-on threshold of the power switch module 20 to reduce on-resistance and conduction loss. As an example and not a limitation, for common power MOSFETs, the amplitude of the positive voltage drive signal can be 10V to 15V to ensure that the MOSFET is fully turned on.

[0094] In some embodiments of this application, the switch driving unit 122 is further configured to output a negative voltage driving signal to the power switch module 20 in response to a negative voltage level signal. Specifically, the other end of the switch driving unit 122 is connected to the first end of the isolation energy storage module 130, and the switch driving unit 122 can receive the negative voltage level signal when the isolation energy storage module 130 generates a negative voltage level signal.

[0095] Furthermore, the switch drive unit 122 converts or transmits the negative voltage level signal into a negative voltage drive signal and outputs it to the control terminal of the power switch module 20. It is easy to understand that the negative voltage drive signal is a negative voltage signal lower than the reference ground, which can quickly draw away the charge from the control terminal of the power switch module 20 and achieve rapid turn-off.

[0096] As an example and not a limitation, when the control signal transitions from a high level to a low level, the push-pull switch unit 121 stops outputting the first drive signal, the switch level unit 123 turns off, and the first terminal of the isolation energy storage module 130 generates a negative voltage level signal. After receiving the negative voltage level signal, the switch drive unit 122 transmits or converts it into a negative voltage drive signal and applies it to the power switch module 20 to quickly remove the gate charge, thereby causing the power switch module 20 to turn off rapidly.

[0097] Specifically, during the conduction phase, when the control signal is high, the push-pull switch unit 121 receives the high-level control signal and then conducts, outputting a first drive signal. The first drive signal is simultaneously transmitted to the switch level unit 123 and the switch drive unit 122.

[0098] Furthermore, the switching level unit 123 responds to the first drive signal by conducting, providing a zero level to the first terminal of the isolated energy storage module 130. It is easy to understand that at this time, the level input module 110 provides a first level to the second terminal of the isolated energy storage module 130, a potential difference is formed between the two terminals of the isolated energy storage module 130, and charging and energy storage begin.

[0099] In some embodiments of this application, the switch driving unit 122, in response to a first driving signal, generates a positive voltage driving signal and outputs it to the power switch module 20, thereby driving the power switch module 20 to conduct. By way of example and not limitation, the switch driving unit 122 may obtain energy from a power supply and, under the control of the first driving signal, convert the supply voltage into a positive voltage driving signal suitable for driving the power switch module 20.

[0100] It is easy to understand that during the entire high-level period, the push-pull switch unit 121 continuously outputs the first drive signal, the switch level unit 123 continuously provides a zero level to the isolated energy storage module 130, the switch drive unit 122 continuously outputs a positive voltage drive signal, the power switch module 20 remains in the on state, and the isolated energy storage module 130 continues to charge.

[0101] In some embodiments of this application, during the shutdown phase, when the control signal transitions from a high level to a low level, the push-pull switch unit 121 receives the low-level control signal and shuts down, stopping the output of the first drive signal.

[0102] Specifically, after the switching level unit 123 loses the first drive signal, it turns off and stops providing a zero level to the first terminal of the isolated energy storage module 130, and the connection between the first terminal and the reference ground is cut off. At this time, the level input module 110 reduces the level provided to the second terminal of the isolated energy storage module 130 from the first level to the second level, and the potential of the second terminal of the isolated energy storage module 130 suddenly drops.

[0103] Furthermore, since the switching level unit 123 has been turned off, the first terminal of the isolation energy storage module 130 is no longer clamped to zero level, and the potential of the first terminal decreases accordingly as the potential of the second terminal decreases, generating a negative voltage level signal. As an example and not a limitation, if the potential of the second terminal decreases by ΔV, the potential of the first terminal also decreases by ΔV, from zero level to -ΔV, forming a negative voltage.

[0104] In some embodiments of this application, the switch driving unit 122 stops generating a positive voltage driving signal after the switch push-pull unit 121 stops outputting the first driving signal. Simultaneously, the switch driving unit 122 receives a negative voltage level signal from the first terminal of the isolated energy storage module 130, and in response to the negative voltage level signal, outputs a negative voltage driving signal to the power switch module 20.

[0105] The switch drive unit 122 has bidirectional driving capability, capable of generating a positive voltage drive signal under the action of the first drive signal, and outputting a negative voltage drive signal under the action of a negative voltage level signal. Specifically, the circuit structure of the switch drive unit 122 allows the negative voltage of the isolation energy storage module 130 to be transmitted to the control terminal of the power switch module 20 through the switch drive unit 122, thereby realizing negative voltage shutdown.

[0106] Furthermore, the negative pressure drive signal quickly removes the charge from the control terminal of the power switch module 20, causing the power switch module 20 to turn off rapidly, while resisting interference caused by the Miller capacitance effect and avoiding false turn-on.

[0107] In some embodiments of this application, reference is made to Figure 4 The signal input module 140 includes a fifteenth resistor R15 and an AND logic gate U1A. Specifically, the AND logic gate U1A is a digital logic gate circuit with two input terminals and one output terminal, which implements the logical AND operation function.

[0108] Furthermore, a pulse width modulation (PWM) signal is connected to the first input terminal of the logic gate U1A. It is easy to understand that the PWM signal generated by the external control system is input to the first input terminal of the logic gate U1A via the signal line, serving as the primary control input.

[0109] In some embodiments of this application, the second input terminal of the AND gate U1A is connected to the first terminal of the fifteenth resistor R15. The second terminal of the fifteenth resistor R15 is connected to the supply voltage VCC. It is easy to understand that the fifteenth resistor R15 acts as a pull-up resistor, pulling the second input terminal of the AND gate U1A to a high level.

[0110] As an example, and not a limitation, when no other control signal is connected to the second input of AND gate U1A, the second input is held high by the pull-up effect of the fifteenth resistor R15. In this case, the output state of AND gate U1A is entirely determined by the pulse width modulation (PWM) signal at the first input: when the PWM signal is high, both inputs are high, resulting in a high output; when the PWM signal is low, the first input is low, resulting in a low output.

[0111] Furthermore, in certain application scenarios, an enable signal can be introduced between the fifteenth resistor R15 and the second input terminal of the logic gate U1A to enable control of the drive circuit. Specifically, when the enable signal is high, the pulse width modulation signal is allowed to pass; when the enable signal is low, a low output is forced, disabling the drive function.

[0112] In some embodiments of this application, the output terminal of logic gate U1A outputs a control signal, which is connected to the level input module 110 and the push-pull drive module 120 respectively, to provide synchronous control signals for both.

[0113] In some embodiments of this application, reference is made to Figure 4 The push-pull switch unit 121 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first switch Q1, and a second switch Q2.

[0114] Specifically, the first terminal of the first resistor R1 is connected to the control signal. It is easy to understand that the first resistor R1 receives the control signal output from the signal input module 140. The first resistor R1 serves as a current limiter and protector in the circuit, preventing excessive current from flowing through the output terminal of the control signal source.

[0115] Furthermore, the second terminal of the first resistor R1 is connected to the first terminal of the second resistor R2 and the base of the first switching transistor Q1. By way of example and not limitation, the first switching transistor Q1 is an NPN transistor, with the base as the control terminal, and the first resistor R1 and the second resistor R2 together provide bias to the base.

[0116] In some embodiments of this application, the second terminal of the second resistor R2 and the emitter of the first switching transistor Q1 are connected to reference ground GND. The second resistor R2 is connected between the base and emitter of the first switching transistor Q1, providing a bias circuit between the base and emitter. At the same time, when the control signal is low, the base potential is pulled down to ground potential through the second resistor R2 to ensure that the first switching transistor Q1 is reliably turned off.

[0117] Specifically, when the control signal is high, current flows through the first resistor R1 to the base of the first switching transistor Q1, while a portion of the current flows through the second resistor R2 to ground. This base current causes the first switching transistor Q1 to enter a saturation conduction state, forming a low-impedance path between the collector and emitter. When the control signal is low, the first resistor R1 no longer provides base current, and the second resistor R2 pulls the base potential down to ground, turning off the first switching transistor Q1.

[0118] In some embodiments of this application, the collector of the first switch Q1 is connected to the second terminal of the third resistor R3. The first terminal of the third resistor R3 is connected to the first terminal of the fourth resistor R4 and the base of the second switch Q2. The first switch Q1 and the second switch Q2 form a push-pull amplifier circuit structure, which improves the driving capability through cascaded amplification.

[0119] Specifically, the third resistor R3 and the fourth resistor R4 constitute the base bias network of the second switch Q2. By way of example and not limitation, the second switch Q2 is a PNP transistor, with the base as the control terminal, which requires a low-level signal to turn on.

[0120] Furthermore, the second terminal of the fourth resistor R4 and the emitter of the second switch Q2 are connected to the supply voltage VCC. The fourth resistor R4 is connected between the supply voltage VCC and the base of the second switch Q2, providing a base pull-up current. When the first switch Q1 is turned off, the base of the second switch Q2 is pulled up to a high level through the third resistor R3 and the fourth resistor R4, thus turning off the second switch Q2.

[0121] In some embodiments of this application, when the control signal is high, the first switch Q1 is turned on, its collector potential is pulled down to near ground potential, the base of the second switch Q2 is pulled low through the third resistor R3, the second switch Q2 is turned on, and its collector outputs a high-level signal. When the control signal is low, the first switch Q1 is turned off, the base of the second switch Q2 is pulled high through the fourth resistor R4, the second switch Q2 is turned off, and its collector stops outputting a high-level signal.

[0122] Furthermore, the collector of the second switch Q2 is connected to the first terminal of the fifth resistor R5, the signal input terminal of the switch level unit 123, and the signal input terminal of the switch drive unit 122. The signal output from the collector of the second switch Q2 is the first drive signal, which simultaneously drives the switch level unit 123 and the switch drive unit 122.

[0123] In some embodiments of this application, the second terminal of the fifth resistor R5 is connected to the first terminal of the isolated energy storage module 130. Specifically, the fifth resistor R5 serves as a current limiter and damper in the circuit, preventing oscillation or overshoot between the isolated energy storage module 130 and the push-pull switch unit 121. By way of example and not limitation, the resistance value of the fifth resistor R5 is chosen appropriately so as not to affect the signal transmission speed while providing the necessary damping effect.

[0124] In some embodiments of this application, reference is made to Figure 4 The switching level unit 123 includes a seventh resistor R7, an eighth resistor R8, a twelfth resistor R12, and a fifth switching transistor Q5.

[0125] Specifically, the first end of the seventh resistor R7 is connected to the signal output terminal of the push-pull switch unit 121, which is the collector of the second switch Q2. It is easy to understand that the seventh resistor R7 receives the first drive signal. The seventh resistor R7 acts as a current limiter in the circuit, providing a suitable drive current to the base of the fifth switch Q5.

[0126] Furthermore, the second terminal of the seventh resistor R7 is connected to the first terminal of the twelfth resistor R12 and the first terminal of the eighth resistor R8. By way of example and not limitation, the seventh resistor R7, the twelfth resistor R12, and the eighth resistor R8 form three branches at this node, each performing a different function.

[0127] In some embodiments of this application, the second terminal of the twelfth resistor R12 is connected to the base of the fifth switch Q5. The second terminal of the eighth resistor R8 and the emitter of the fifth switch Q5 are connected to reference ground GND. It is easy to understand that the twelfth resistor R12 and the eighth resistor R8 together constitute the base bias network of the fifth switch Q5.

[0128] Specifically, the twelfth resistor R12 is the base series resistor, which adjusts the base current; the eighth resistor R8 is the base-emitter pull-down resistor, which pulls the base down to ground potential when the first drive signal is low, ensuring that the fifth switch Q5 is reliably turned off. As an example and not a limitation, the fifth switch Q5 is an NPN transistor.

[0129] Furthermore, the collector of the fifth switch Q5 is connected to the first terminal of the isolated energy storage module 130. When the fifth switch Q5 is turned on, a low-impedance path is formed between its collector and emitter, connecting the first terminal of the isolated energy storage module 130 to the reference ground GND, providing a zero level. When the fifth switch Q5 is turned off, the first terminal of the isolated energy storage module 130 is disconnected from the reference ground, allowing the potential to change freely.

[0130] In some embodiments of this application, when the first drive signal is high, current flows through the seventh resistor R7 and the twelfth resistor R12 to the base of the fifth switch Q5, providing base current and causing the fifth switch Q5 to saturate and conduct, clamping the first terminal of the isolation energy storage module 130 at zero level. When the first drive signal is low, the seventh resistor R7 no longer provides base current, the eighth resistor R8 pulls the base down to ground potential, the fifth switch Q5 is turned off, and the first terminal of the isolation energy storage module 130 is left floating, creating conditions for generating a negative voltage.

[0131] In some embodiments of this application, reference is made to Figure 4 The switch drive unit 122 includes a sixth resistor R6, a third switch Q3, and a fourth switch Q4.

[0132] Specifically, the base of the third switch Q3 is connected to the base of the fourth switch Q4 and the signal output terminal of the push-pull unit 121. It is easy to understand that the bases of the third switch Q3 and the fourth switch Q4 are connected together to receive the first drive signal, forming a push-pull output structure.

[0133] In some embodiments of this application, the collector of the third switch Q3 is connected to the power supply voltage VCC. By way of example and not limitation, the third switch Q3 is a PNP transistor with its collector connected to the positive terminal of the power supply and its emitter serving as the output terminal. When the base is low, the third switch Q3 is turned on, and the emitter outputs a high level close to VCC; when the base is high, the third switch Q3 is turned off.

[0134] Furthermore, the emitter of the third switch Q3 is connected to the emitter of the fourth switch Q4 and the first terminal of the sixth resistor R6. It is easy to understand that the emitters of the third switch Q3 and the fourth switch Q4 are connected together to form a push-pull output node, which is connected to the power switch module 20 through the sixth resistor R6.

[0135] In some embodiments of this application, the collector of the fourth switch Q4 is connected to the first terminal of the isolated energy storage module 130. By way of example and not limitation, the fourth switch Q4 is an NPN transistor, with its collector connected to the first terminal of the isolated energy storage module 130 and its emitter serving as the output terminal. When the base is high, the fourth switch Q4 is turned on, and the emitter is pulled to a potential close to the collector; when the base is low, the fourth switch Q4 is turned off.

[0136] Furthermore, the second terminal of the sixth resistor R6 is connected to the control terminal of the power switch module 20. Specifically, the sixth resistor R6 plays a role in current limiting and damping in the drive output circuit, preventing excessive drive current or oscillation.

[0137] In some embodiments of this application, when the first drive signal is high, the base of the third switch Q3 is high, and the third switch Q3 is turned off; the base of the fourth switch Q4 is high, and the fourth switch Q4 is turned on. It is easy to understand that at this time, the fifth switch Q5 is also turned on, and the first terminal of the isolation energy storage module 130 is clamped at zero level.

[0138] Specifically, after the fourth switch Q4 is turned on, its emitter potential is pulled close to the collector potential, i.e., close to zero level. Through the sixth resistor R6, the zero-level signal is transmitted to the control terminal of the power switch module 20. At the same time, although the third switch Q3 is turned off, since the fourth switch Q4 has clamped the output terminal to a low level, the third switch Q3 does not affect the output state.

[0139] Furthermore, in the ON state, the control terminal of the power switch module 20 is connected to the first terminal of the isolated energy storage module 130 through the sixth resistor R6 and the fourth switch Q4, while the first terminal is clamped at zero level by the fifth switch Q5. By way of example and not limitation, the gate potential of the power switch module 20 is at zero level or slightly above zero level (depending on the gate residual charge), and the MOSFET is in a state of about to turn on or turn on.

[0140] In some embodiments of this application, a positive voltage drive path is also designed in the circuit to provide a sufficient positive voltage drive signal in the on state. Specifically, when the control signal is high and a positive voltage drive signal needs to be output, the power switch module 20 can be charged from the supply voltage VCC to the control terminal through an additional circuit path.

[0141] It is easy to understand that when the third switch Q3 is in the off state, its emitter is connected to zero level through the fourth switch Q4. However, when the isolation energy storage module 130 is fully charged, it can provide a positive voltage drive current to the power switch module 20 through the brief conduction of the third switch Q3 or other auxiliary circuits, so that the control terminal voltage rises above the conduction threshold and achieves reliable conduction.

[0142] In some embodiments of this application, when the first drive signal transitions from a high level to a low level, the base of the third switch Q3 is at a low level, and the third switch Q3 is turned on; the base of the fourth switch Q4 is at a low level, and the fourth switch Q4 is turned off.

[0143] Specifically, after the third switch Q3 is turned on, its emitter potential is pulled to near the collector potential, i.e., close to VCC. However, at this time, the fifth switch Q5 is turned off, and the first terminal of the isolation energy storage module 130 is no longer clamped at zero level. Instead, due to the level input module 110 reducing the potential of the second terminal from the first level to the second level, a negative voltage is generated at the first terminal.

[0144] Furthermore, after the fourth switch Q4 is turned off, its collector and emitter are disconnected. The negative voltage at the first end of the isolation energy storage module 130 is transmitted to the emitter through the collector-base junction (reverse biased) of the fourth switch Q4 and other paths. However, the collector of the fourth switch Q4 is in a negative voltage state, which will affect the operating state of the fourth switch Q4.

[0145] In some embodiments of this application, when the third switch Q3 is turned on, an attempt is made to pull the output terminal to a high level, but the control terminal of the power switch module 20 needs to be quickly discharged and turned off. Specifically, the negative voltage at the first terminal of the isolation energy storage module 130 is transmitted to the control terminal of the power switch module 20 through a parasitic path or a designed discharge path.

[0146] It is easy to understand that although the fourth switch Q4 is off, the negative voltage at its collector will couple to the base through the collector-base capacitor, thus affecting the emitter potential. At the same time, the charge at the control terminal of the power switch module 20 can flow to the first terminal of the isolated energy storage module 130 through the sixth resistor R6, completing rapid discharge.

[0147] Furthermore, the energy stored in the isolation energy storage module 130 provides a powerful charge extraction capability, quickly pulling the potential of the control terminal of the power switch module 20 down to a negative value, achieving rapid turn-off. By way of example and not limitation, the gate voltage of the power switch module 20 is pulled to a few to tens of negative volts, rapidly removing the gate charge, causing the MOSFET to turn off quickly, while resisting the Miller capacitance effect.

[0148] In some embodiments of this application, reference is made to Figure 4 The level input module 110 includes a first diode D1, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a sixth switch Q6, and a seventh switch Q7.

[0149] Specifically, the second terminal of the ninth resistor R9 is connected to the control signal. It's easy to understand that the level input module 110 receives the same control signal as the push-pull drive module 120, ensuring timing synchronization. The ninth resistor R9 serves as a current limiter in the circuit.

[0150] Furthermore, the first terminal of the ninth resistor R9 is connected to the base of the seventh switch Q7. By way of example and not limitation, the seventh switch Q7 is an NPN transistor, and its base receives the control signal through the ninth resistor R9.

[0151] In some embodiments of this application, the collector of the seventh switch Q7 is connected to the base of the sixth switch Q6 and the second terminal of the tenth resistor R10. The first terminal of the tenth resistor R10 is connected to the supply voltage VCC. It is easy to understand that the seventh switch Q7 and the sixth switch Q6 form a cascaded amplifier circuit, and the tenth resistor R10 provides bias current to the base of the sixth switch Q6.

[0152] Specifically, when the control signal is high, the ninth resistor R9 provides base current, the seventh switch Q7 is turned on, its collector potential is pulled low to near ground potential, the base of the sixth switch Q6 is pulled low, and the sixth switch Q6 is turned off. When the control signal is low, the seventh switch Q7 is turned off, the tenth resistor R10 pulls the base of the sixth switch Q6 high, and the sixth switch Q6 is turned on.

[0153] In some embodiments of this application, the emitter of the sixth switch Q6 and the emitter of the seventh switch Q7 are connected to reference ground GND. By way of example and not limitation, the sixth switch Q6 is an NPN transistor with its emitter grounded and its collector serving as the output terminal.

[0154] Furthermore, the collector of the sixth switch Q6 is connected to the second terminal of the isolated energy storage module 130 and the cathode of the first diode D1. The anode of the first diode D1 is connected to the second terminal of the eleventh resistor R11. The first terminal of the eleventh resistor R11 is connected to the supply voltage VCC.

[0155] It is easy to understand that the eleventh resistor R11 and the first diode D1 are connected in series between the supply voltage VCC and the collector of the sixth switch Q6, providing a level signal to the second terminal of the isolated energy storage module 130.

[0156] In some embodiments of this application, when the control signal is high, the sixth switch Q6 is turned off, its collector is in a high-resistance state, and current flows from the supply voltage VCC through the eleventh resistor R11 and the first diode D1 to the second terminal of the isolated energy storage module 130, causing the potential of the second terminal to rise to the first level. Specifically, the first level is approximately equal to VCC minus the forward voltage drop of the first diode D1, for example, VCC - 0.7V.

[0157] Furthermore, the function of the first diode D1 is to prevent reverse current flow. When the sixth switch Q6 is turned on, without the first diode D1, the charge stored in the isolation energy storage module 130 might flow back to the power supply through the eleventh resistor R11, affecting the circuit operation. The presence of the first diode D1 ensures that current can only flow from the power supply to the isolation energy storage module 130 and cannot flow in the reverse direction.

[0158] In some embodiments of this application, when the control signal transitions from a high level to a low level, the sixth switch Q6 changes from off to on, and its collector potential is rapidly pulled down to near ground potential. The potential at the second terminal of the isolated energy storage module 130 then abruptly drops from the first level to the second level (near zero level). Specifically, the on-state of the sixth switch Q6 provides a low-impedance discharge path from the second terminal of the isolated energy storage module 130 to the reference ground, rapidly changing the potential at the second terminal.

[0159] Furthermore, the sudden drop in the second terminal potential causes a corresponding drop in the first terminal potential of the isolation energy storage module 130, generating a negative voltage level signal to achieve the negative voltage shutdown function.

[0160] In some embodiments of this application, reference is made to Figure 4 The isolated energy storage module 130 includes a first capacitor C1 and a thirteenth resistor R13.

[0161] Specifically, the first terminal of the first capacitor C1 is connected to the level output terminal of the push-pull drive module 120. The level output terminal of the push-pull drive module 120 is the node where the collector of the fifth switch Q5, the collector of the fourth switch Q4, and the second terminal of the fifth resistor R5 are connected. This node is the first terminal of the isolation energy storage module 130.

[0162] Furthermore, the second terminal of the first capacitor C1 is connected to the level output terminal of the level input module 110. By way of example and not limitation, the level output terminal of the level input module 110 is the node where the collector of the sixth switch Q6 and the cathode of the first diode D1 are connected, and the node is the second terminal of the isolation energy storage module 130.

[0163] In some embodiments of this application, the thirteenth resistor R13 is connected in parallel across the first capacitor C1. Specifically, the two ends of the thirteenth resistor R13 are respectively connected to the first and second ends of the first capacitor C1, forming an RC parallel structure with the first capacitor C1.

[0164] When a potential difference exists between the first and second terminals, an electric field is established across the first capacitor C1, storing charge and energy. The capacitance value of the first capacitor C1 determines its energy storage capacity; the larger the capacitance value, the more energy is stored, and the longer the negative voltage is maintained.

[0165] As an example and not a limitation, the capacitance value of the first capacitor C1 can be selected from tens of nanofarads to several microfarads. The specific value is determined comprehensively based on factors such as the gate capacitance of the power switch module 20, the desired negative voltage amplitude, and the duration of the negative voltage. If the capacitance value of the first capacitor C1 is too small, the energy storage will be insufficient, resulting in a small negative voltage amplitude or a short duration of the negative voltage, leading to poor turn-off performance. If the capacitance value is too large, the charging time will be long, affecting the operating frequency of the circuit and increasing cost and size.

[0166] In some embodiments of this application, the thirteenth resistor R13 plays multiple roles in the circuit. First, it provides a DC path. The thirteenth resistor R13 provides a DC charging and discharging path for the first capacitor C1. After long-term operation, the thirteenth resistor R13 achieves charge balance and prevents the potential at the ends of the first capacitor C1 from accumulating and drifting.

[0167] Furthermore, it is used to limit leakage current. In practical applications, the first capacitor C1 experiences leakage current. The thirteenth resistor R13, connected in parallel, provides a shunt path for this leakage current, reducing its impact on the energy storage state of the first capacitor C1. Finally, it also acts as a damper. The thirteenth resistor R13 and the first capacitor C1 form an RC circuit, providing a certain damping effect and suppressing circuit oscillation.

[0168] As an example, not a limitation, the choice of the resistance value of the thirteenth resistor R13 requires careful consideration. If the resistance is too small, it will generate a large leakage current during charging, reducing charging efficiency and energy storage; if the resistance is too large, it will have less impact on circuit operation but will lose the aforementioned benefits. Typically, the resistance value of the thirteenth resistor R13 is chosen to be from several thousand ohms to tens of thousands of ohms.

[0169] In some embodiments of this application, during the charging phase, the potential at the second terminal of the first capacitor C1 is at a first level (close to VCC), and the potential at the first terminal is at zero level. The potential difference between the two terminals is VCC, and current flows from the second terminal to the first terminal (through the inside of the first capacitor C1), charging and storing energy in the first capacitor C1. Simultaneously, a voltage of VCC also exists across the thirteenth resistor R13, and current flows through the thirteenth resistor R13 from the second terminal to the first terminal. However, due to the large resistance of the thirteenth resistor R13, the current is small, and the main charging current flows through the first capacitor C1.

[0170] Furthermore, during the discharge phase, when the potential at the second terminal suddenly drops to zero, the potential at the first terminal cannot follow instantaneously due to the energy storage characteristics of the first capacitor C1, and maintains its original potential relationship relative to the second terminal. Therefore, the potential at the first terminal drops from zero to a negative value, generating a negative voltage. The energy stored in the first capacitor C1 is released to the power switch module 20 through the switch drive unit 122, achieving rapid turn-off.

[0171] In some embodiments of this application, reference is made to Figure 4 The power switch module 20 includes a power MOSFET Q8, a fourteenth resistor R14, and a tenth resistor R10.

[0172] Specifically, the power MOSFET Q8 is an N-channel enhancement-mode MOSFET with three pins: gate (G), drain (D), and source (S). The gate (G) is the control terminal, connected to the output of the switch drive unit 122 via the sixth resistor R6 to receive the drive signal.

[0173] Furthermore, the source (S) of the power MOSFET Q8 is connected to the first terminal of the fourteenth resistor R14. The second terminal of the fourteenth resistor R14 is connected to the reference ground (GND). It is easy to understand that the fourteenth resistor R14 is a source series resistor, which in some applications can serve the functions of current sampling, current limiting protection, or improving switching characteristics. As an example and not a limitation, when these functions are not required, the fourteenth resistor R14 can be omitted, and the source (S) can be directly grounded.

[0174] In some embodiments of this application, the drain D of the power MOSFET Q8 is connected to the load or the power bus VBUS. Specifically, power current flows from VBUS through the drain-source channel of the power MOSFET Q8 to the load or ground, thus achieving power transfer. The on / off state of the power MOSFET Q8 controls the on / off state of the power current.

[0175] Furthermore, the tenth resistor R10 is connected between the gate G and source S of the power MOSFET Q8, or between the gate G and the reference ground GND. It is easy to understand that the tenth resistor R10 is a gate-source pull-down resistor. When the power MOSFET Q8 is not driven or the drive signal is low, it pulls the gate potential down to the source potential, ensuring that the power MOSFET Q8 is reliably turned off and preventing false turn-on in a floating state.

[0176] As an example rather than a limitation, the value of the tenth resistor R10 is typically chosen to be between several thousand ohms and tens of thousands of ohms, which provides sufficient pull-down effect without consuming excessive drive power when the drive signal is applied.

[0177] In some embodiments of this application, when the switch drive unit 122 outputs a positive voltage drive signal, the positive voltage is applied to the gate G of the power MOSFET Q8 through the sixth resistor R6, the gate-source voltage VGS rises to a positive value and exceeds the threshold voltage, the power MOSFET Q8 is turned on, a low-impedance channel is formed between the drain D and the source S, and the power current flows.

[0178] Furthermore, when the switching drive unit 122 outputs a negative voltage drive signal, the negative voltage is applied to the gate G of the power MOSFET Q8 through the sixth resistor R6. The gate-source voltage VGS rapidly drops to a negative value, quickly removing the gate charge. The power MOSFET Q8 is quickly turned off, and the drain D and source S return to a high impedance state, cutting off the power current. The negative voltage drive can also resist the Miller capacitance effect, preventing gate voltage fluctuations caused by gate-drain capacitance coupling when the drain-source voltage rises.

[0179] In some embodiments of this application, the complete operating timing of the negative voltage shutdown type drive circuit 10 is as follows: Specifically, in the initial power-on state, the control signal is low, and the output of logic gate U1A is low. The first switch Q1 is off, the second switch Q2 is off, and the first drive signal is low. The fifth switch Q5 is off, the third switch Q3 is on, and the fourth switch Q4 is off. The seventh switch Q7 is off, and the sixth switch Q6 is on.

[0180] Furthermore, the first terminal of the isolated energy storage module 130 is left floating, and the second terminal is connected to ground potential (second level) through the sixth switch Q6. The gate of the power MOSFET Q8 is pulled down to ground potential through the tenth resistor R10, and the power MOSFET Q8 is turned off.

[0181] In some embodiments of this application, when the pulse width modulation signal PWM transitions from low to high, the logic gate U1A outputs a high-level control signal. The first switch Q1 is turned on, pulling down the base of the second switch Q2, which in turn turns on and outputs a high-level first drive signal.

[0182] Specifically, after receiving the high-level first drive signal, the fifth switch Q5 turns on, clamping the first terminal of the isolated energy storage module 130 to zero level. At the same time, the seventh switch Q7 turns on, pulling down the base of the sixth switch Q6, causing the sixth switch Q6 to turn off, and the potential of the second terminal of the isolated energy storage module 130 rises to the first level (VCC-0.7V).

[0183] Furthermore, a potential difference is formed across the two ends of the isolated energy storage module 130, and the first capacitor C1 is charged and stores energy. The fourth switch Q4 turns on after receiving the high-level first drive signal, but since the first terminal is clamped to zero level by the fifth switch Q5, the output terminal potential is close to zero level.

[0184] In some embodiments of this application, a positive voltage needs to be applied to the gate to turn on the power MOSFET Q8. In practical circuits, a positive voltage drive signal can be provided to the gate during the turn-on phase using a pre-charge circuit or other auxiliary circuitry. Alternatively, the circuit design can ensure that the gate voltage rises above a threshold value during the initial turn-on phase.

[0185] In some embodiments of this application, when the pulse width modulation signal PWM transitions from a high level to a low level, the logic gate U1A outputs a low-level control signal. The first switch Q1 is turned off, the second switch Q2 is turned off, and the first drive signal becomes low.

[0186] Specifically, the fifth switch Q5 is turned off, releasing the clamp on the first terminal of the isolated energy storage module 130. At the same time, the seventh switch Q7 is turned off, and the sixth switch Q6 is turned on, pulling the potential of the second terminal of the isolated energy storage module 130 down from the first level to the second level (close to zero level).

[0187] Furthermore, due to the energy storage characteristics of the first capacitor C1, the potential at the first terminal cannot instantly follow the change at the second terminal. When the potential at the second terminal drops by ΔV, the potential at the first terminal also drops by ΔV, from zero level to negative voltage -ΔV, generating a negative voltage level signal.

[0188] In some embodiments of this application, the third switch Q3 and the fourth switch Q4 receive a low-level first drive signal, with the third switch Q3 turned on and the fourth switch Q4 turned off. The negative voltage at the first terminal is transferred to the gate of the power MOSFET Q8 through the sixth resistor R6, forming a negative gate-source voltage and quickly removing the gate charge.

[0189] Specifically, the gate voltage of power MOSFET Q8 rapidly drops to a negative value, and the gate charge flows through the sixth resistor R6 to the first terminal of the isolation energy storage module 130. The energy stored in the first capacitor C1 is used to extract the gate charge. Power MOSFET Q8 is quickly turned off, the drain-source channel is cut off, and the power current is interrupted.

[0190] Furthermore, the negative voltage drive signal is continuously applied to the gate to resist the Miller capacitance effect generated when the drain-source voltage rises, prevent the gate voltage from rising unexpectedly and causing false turn-on, and ensure the reliable turn-off of the power MOSFET Q8.

[0191] In some other embodiments of this application, an energy storage power supply is also provided, which includes the negative voltage shutdown type drive circuit as described in any of the above specific embodiments.

[0192] 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 negative voltage turn-off type drive circuit, characterized in that, include: A level input module is used to receive control signals, provide a first level to the isolated energy storage module when the control signal is high, and provide a second level to the isolated energy storage module when the control signal is low; the first level is higher than the second level. The push-pull drive module, connected to the power switch module, is used to receive the control signal. When the control signal is high, it outputs a positive voltage drive signal to drive the power switch module to turn on and provides a zero level for the isolated energy storage module. An isolated energy storage module, wherein the second end of the isolated energy storage module is connected to the level input module, and the first end of the isolated energy storage module is connected to the push-pull drive module, for outputting a negative voltage level signal to the push-pull drive module in response to the first level switching to the second level when the control signal is low; The push-pull drive module is also used to output a negative voltage drive signal to the power switch module in response to the negative voltage level signal when the control signal is low.

2. The circuit according to claim 1, characterized in that, The push-pull drive module includes: A push-pull switch unit is configured to turn on in response to a high-level control signal and output a first drive signal; and to turn off in response to a low-level control signal and stop outputting the first drive signal. A switching level unit, connected to the switch push-pull unit, is used to provide the zero level to the isolated energy storage module in response to the first drive signal being turned on. A switch driving unit, connected to the switch push-pull unit and the power switch module, is used to generate the positive voltage driving signal in response to the first driving signal; and to output the negative voltage driving signal to the power switch module in response to the negative voltage level signal.

3. The circuit according to claim 2, characterized in that, The push-pull switch unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first switch transistor, and a second switch transistor. The first end of the first resistor is connected to the control signal, the second end of the first resistor is connected to the first end of the second resistor and the base of the first switching transistor, the collector of the first switching transistor is connected to the second end of the third resistor, the first end of the third resistor is connected to the first end of the fourth resistor and the base of the second switching transistor, and the emitter of the second switching transistor and the second end of the fourth resistor are connected to the power supply voltage. The collector of the second switch is connected to the first end of the fifth resistor, the signal input terminal of the switch level unit, and the signal input terminal of the switch drive unit. The second end of the fifth resistor is connected to the first end of the isolated energy storage module. The second end of the second resistor and the emitter of the first switch are connected to reference ground.

4. The circuit according to claim 2, characterized in that, The switching level unit includes a seventh resistor, an eighth resistor, a twelfth resistor, and a fifth switching transistor; The first end of the seventh resistor is connected to the signal output terminal of the push-pull switch unit, the second end of the seventh resistor is connected to the first end of the twelfth resistor and the first end of the eighth resistor, the second end of the twelfth resistor is connected to the base of the fifth switch, the collector of the fifth switch is connected to the first terminal of the isolated energy storage module, and the second end of the eighth resistor and the emitter of the fifth switch are connected to the reference ground.

5. The circuit according to claim 2, characterized in that, The switch driving unit includes a sixth resistor, a third switch transistor, and a fourth switch transistor; The base of the third switch is connected to the base of the fourth switch and the signal output terminal of the push-pull switch unit. The collector of the third switch is connected to the power supply voltage. The emitter of the third switch is connected to the emitter of the fourth switch and the first terminal of the sixth resistor. The collector of the fourth switch is connected to the first terminal of the isolation energy storage module. The second terminal of the sixth resistor is connected to the power switch module.

6. The circuit according to claim 1, characterized in that, The level input module includes a first diode, a ninth resistor, a tenth resistor, an eleventh resistor, a sixth switch, and a seventh switch. The second end of the ninth resistor is connected to the control signal, the first end of the ninth resistor is connected to the base of the seventh switch, the collector of the seventh switch is connected to the base of the sixth switch and the second end of the tenth resistor, and the first end of the tenth resistor is connected to the power supply voltage. The collector of the sixth switch is connected to the second terminal of the isolated energy storage module and the cathode of the first diode. The anode of the first diode is connected to the second terminal of the eleventh resistor. The first terminal of the eleventh resistor is connected to the power supply voltage. The emitters of the sixth switch and the seventh switch are connected to the reference ground.

7. The circuit according to claim 1, characterized in that, The isolated energy storage module includes a first capacitor and a thirteenth resistor; The first terminal of the first capacitor is connected to the level output terminal of the push-pull drive module, the second terminal of the first capacitor is connected to the level output terminal of the level input module, and the thirteenth resistor is connected in parallel across the first capacitor.

8. The circuit according to claim 1, characterized in that, Also includes: The signal input module, along with the level input module and the push-pull drive module, is used to receive pulse width modulation signals and output the control signals.

9. The circuit according to claim 8, characterized in that, The signal input module includes a fifteenth resistor and an AND logic gate; The first input terminal of the AND logic gate is connected to the pulse width modulation signal, the second terminal of the AND logic gate is connected to the first terminal of the fifteenth resistor, and the second terminal of the fifteenth resistor is connected to the power supply voltage.

10. An energy storage power source, characterized in that, include: The negative voltage shutdown type drive circuit as described in any one of claims 1-9.

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