Isolation driving control circuit suitable for high-voltage SSPC

Abstract

An isolation driving control circuit suitable for a high-voltage SSPC comprises a hard wire interface circuit, an isolation power supply conversion circuit, a driving circuit, a current sampling circuit and a temperature sampling circuit. According to the invention, the isolation power supply conversion circuit and the grid voltage regulation circuit are designed to be combined with the low-pass filter circuit, the short-circuit protection circuit and the maximum current acquisition / storage circuit, so that the safety isolation driving circuit suitable for the high-voltage SSPC solid-state power controller is ingeniously realized; the circuit can realize the functions of large capacitive load starting, short-circuit current peak suppression, short-circuit maximum current recording and the like. The problems that the gate voltage control voltage of a conventional SSPC drive circuit cannot be adjusted, the short-circuit peak current is not controlled under high-voltage application, and the maximum short-circuit current cannot be obtained are solved, and the safety and the intelligent degree of the drive circuit are greatly improved.

Description

Technical Field

[0001] This invention relates to an isolated drive control circuit suitable for high-voltage SSPC, belonging to the field of electronic technology. Background Technology

[0002] High-voltage SSPCs use high-voltage power transistors as their core control switches and are now widely used in various fields. They offer advantages such as contactless operation, arc-free operation, noiseless operation, fast response, low electromagnetic interference, long lifespan, and high reliability. The power transistor operates in a high-side mode and in a non-switching state during steady-state operation, requiring isolated drive during use.

[0003] Traditional SSPC isolation drive circuits have non-adjustable gate voltages, with the amplitude generally dependent on the driver's supply voltage. SSPCs require slow switching characteristics. To achieve this, drive circuits are typically designed with constant voltage or constant current output. Constant voltage output circuits achieve slow switching of the power MOSFET primarily by increasing the RC delay time between the gate voltage output and the MOSFET gate, or by increasing the MOSFET Miller capacitance, thus slowing the gate voltage rise time. Constant current output circuits achieve slow switching by changing the gate charge charging current. The former requires larger capacitors and high-voltage capacitors to achieve a longer delay; for high-voltage SSPCs, this often requires multiple capacitors in series to improve high-voltage withstand performance, resulting in a large circuit size and difficulty in miniaturization. The constant current output method requires sufficiently small gate charging current to control the switching slope, which proportionally extends the non-switching time of the gate charge curve, deteriorating the switching response characteristics.

[0004] Although traditional SSPC circuits have current telemetry output function, the external current telemetry sampling is usually periodic. When a short-circuit overcurrent event occurs and the protection is shut down, the short-circuit protection circuit's action time is usually on the order of microseconds. As a result, it is difficult for the external telemetry to collect the maximum current value during the short circuit, making the fault diagnosis process extremely difficult. Summary of the Invention

[0005] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a brand-new drive control circuit, which solves the problems of uncontrollable gate drive voltage and inability to collect maximum current during short circuit in the SSPC drive control circuit in the prior art. At the same time, it solves the problem of excessive size based on on-chip integration technology.

[0006] The technical solution of this invention is: An isolated drive control circuit suitable for high-voltage SSPC includes: a hard-wired interface circuit, an isolated power conversion circuit, a drive circuit, a current sampling circuit, and a temperature sampling circuit. The hard-wired interface circuit is electrically isolated from the power circuit. The hard-wired interface circuit is used for external PWM control command input, as well as status telemetry, digital level and analog level output. The digital level output includes switch status indication and protection status indication; the analog level output includes current telemetry signal and temperature telemetry signal. The isolated power conversion circuit is used to convert the power supply voltage, and the converted output voltage is sent to the drive circuit and the current sampling circuit. The drive circuit adjusts the gate voltage according to the external PWM control command input from the hard-wired interface circuit. When the current flowing through the resistor RS in the power circuit is higher than the short-circuit threshold, the drive output is quickly turned off. When a short-circuit event occurs in the power circuit, the drive circuit acquires the maximum current value through the current sampling circuit and latches the maximum current of the current power circuit in real time. The current sampling circuit collects the current value on the resistor Rs in the power circuit. After conditioning by the current sampling circuit, the current value is isolated and output to the hard-wired interface circuit as a current telemetry signal. The temperature sampling circuit integrates a temperature sensor on a chip packaged with an isolated drive control circuit to detect chip temperature and transmits the collected chip temperature to a hard-wired interface circuit as a temperature telemetry signal.

[0007] Furthermore, the hard-wired interface circuit, isolated power conversion circuit, drive circuit, and current sampling circuit that make up the isolated drive control circuit are all integrated into a single package.

[0008] Furthermore, the isolated power conversion circuit uses an external resistor R1 outside the package to adjust the first-stage output voltage. The adjustable range of the first-stage output voltage is +12V to +20V, and the adjustment formula is as follows: U VDD2 =12+k1×R1; In the formula, k1 is the proportionality coefficient, R1 is the external resistance, and U VDD2 This is the first-stage output voltage, U. VDD2 The output is given to the drive circuit and the current sampling circuit.

[0009] Furthermore, the isolation power conversion circuit integrates an LDO circuit after the primary output voltage on the secondary side, realizing a secondary conversion of the power supply voltage. The secondary output voltages are 5V and 3.3V, which are output to the maximum current acquisition / storage unit and current sampling circuit in the drive circuit.

[0010] Furthermore, the driving circuit includes a switching slope control circuit, a gate voltage regulation control circuit, and a low-pass filter circuit; the switching slope control circuit is used to control the turn-on and turn-off slope of the power MOSFET M1 in the power circuit; the gate voltage regulation control circuit is used to control the first-stage output voltage U VDD2 The size of the resistor RS is adjusted to adjust the steady-state gate voltage after the power MOSFET M1 is turned on; the low-pass filter circuit is used to filter the pulsating gate voltage level output by the front-stage gate voltage regulation control circuit, thereby achieving the continuity of the OUTH pin voltage output; the power circuit includes a resistor RS and a power MOSFET M1.

[0011] Furthermore, the pulsating gate voltage level V OUTH Its magnitude is controlled by the duty cycle of the PWM waveform, and its mathematical description is as follows: V OUTH =k2×U VDD2 In the formula, k2 is the duty cycle of the PWM waveform, and U VDD2 This is the first-stage output voltage of the isolation converter circuit.

[0012] Furthermore, the normal startup process: V at time 0-t1 OUTH According to U VDD2 Full duty cycle output, at this time V OUTH The output voltage and the first-stage output voltage U on the secondary side of the isolated power conversion circuit VDD2 Maintain consistency; The period from t1 to t3 is the controlled adjustment zone, during which V OUTH Operating in an adjustable duty cycle state, the gate voltage VGS of the power MOSFET M1 in the power circuit stabilizes in the Miller plateau period, and the drain-source current I of the power MOSFET M1... DS Slowly rising, I DS The rise time is controlled by the duty cycle. At time t3-t4, V OUTH Restore to U VDD2 As the gate voltage VGS rises rapidly, the MOSFET on-resistance drops quickly to a stable value. The gate voltage VGS remains constant with U during the time intervals t4-t5. VDD2 The output voltage values ​​are consistent.

[0013] Furthermore, the short-circuit turn-off process: when a short-circuit event occurs in the power circuit at time t6, V OUTH The voltage drops rapidly to 0V. At this point, the gate voltage VGS decreases rapidly because the gate charge enters the discharge period due to the lack of drive power. The period from t6 to t9 is the controlled adjustment zone, during which V OUTHOperating in an adjustable duty cycle state, the gate voltage VGS output voltage drops to the Miller plateau period, and the current I... DS The current drops and enters the current-limiting region, thereby suppressing the peak short-circuit current. The time is controlled by the duty cycle. At time t9, I DS When the value drops to 0, the short-circuit shutdown process ends.

[0014] Furthermore, the driving circuit also includes a short-circuit protection circuit and a maximum current acquisition and storage circuit. The short-circuit protection circuit acquires the voltage difference from the resistor RS through the VS terminal and compares it with a set protection threshold. When the voltage difference from the resistor RS is greater than or equal to the set protection threshold, it outputs a signal to the gate voltage regulation control circuit, which then performs a rapid turn-off action on the power MOSFET M1 in the power circuit through the OUTH and OUTL pins. At the same time, the maximum current value flowing through the resistor RS in the power circuit is acquired and stored through the maximum current acquisition and storage circuit.

[0015] The advantages of this invention compared to the prior art are: (1) The isolation drive control circuit of the present invention, by designing a gate voltage regulation control circuit, can realize the switching slope control and the segmented control of the gate voltage at the same time. Thus, while realizing the slow switching action, it effectively avoids the drawback of lengthening the turn-on and turn-off process. It can effectively suppress the surge current and peak voltage caused by capacitive and inductive loads, improve the load-carrying capacity of the power tube, and avoid the risk of thermal failure of the power tube due to excessive on-resistance caused by staying in the variable resistance region for too long. It improves the reliability and service life of the power tube and ensures that the equipment works safely, stably and reliably. (2) The isolation drive control circuit of the present invention can record the peak current during short-circuit overcurrent by designing a maximum current acquisition / storage circuit. This avoids the fact that traditional SSPCs can only rely on the protection status to identify overcurrent characteristics when short-circuit protection occurs, and cannot evaluate the magnitude of the overcurrent online. The addition of this function can greatly improve the intelligence level of SSPC products, especially providing a quantifiable means of evaluation for the safety and intelligent diagnosis of high-voltage SSPCs, thereby improving the safety of high-voltage SSPCs. (3) The isolated drive control circuit of the present invention integrates the isolated power supply conversion circuit into a single unit, and the voltage can be adjusted through resistor R1 to achieve adaptive adjustment of the steady-state gate voltage of MOSFETs from different manufacturers. This avoids the large product size caused by the separate design of traditional SSPC isolated power conversion circuits and the inability to fully utilize the low on-resistance advantage of MOSFETs due to the use of the same voltage standard by MOSFETs from different manufacturers. It further optimizes the design state, reduces steady-state power consumption, and improves product reliability. Attached Figure Description

[0016] Figure 1 This is a circuit block diagram of the present invention; Figure 2 The waveforms represent key points of the circuit gate voltage regulation and control function of this invention. Detailed Implementation

[0017] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings.

[0018] This invention provides an isolated drive control circuit suitable for high-voltage SSPCs. Unlike traditional SSPC isolated drive control circuits, the main innovations of this invention include the following: 1) Controllable Gate Drive Voltage Output: The gate voltage of traditional SSPC isolated drive circuits is not adjustable, and its amplitude generally depends on the supply voltage of the driver. However, the switching process of SSPC requires a slow switching characteristic. To achieve this characteristic, the drive circuit is generally designed as a constant voltage output or a constant current output. The main means of achieving the slow switching characteristic of the power MOSFET in the constant voltage output circuit is to increase the RC delay time between the gate voltage output and the MOSFET gate or to increase the size of the MOSFET Miller capacitance to slow down the rise time of the gate voltage of the power MOSFET. The constant current output method achieves the slow switching characteristic by changing the gate charge charging current. The former requires a large capacitor and a high voltage-rated capacitor to obtain a large delay. For high voltage SSPC, it is usually necessary to rely on a series multi-capacitor method to improve the high voltage resistance, resulting in a large circuit size and difficulty in miniaturization. The constant current output method requires the gate charging current to be controlled small enough to achieve the control of the switching slope, which causes the non-switching interval time of the gate charge curve to be extended proportionally, resulting in a deterioration of the switching response characteristics. This invention proposes a drive circuit gate voltage regulation control circuit that can realize dynamic adjustment of the gate voltage to achieve segmented control. This solves the drawback of constant voltage output relying on external capacitors and avoids the drawback of poor switching response characteristics caused by constant current output.

[0019] 2) Maximum Current Acquisition / Storage Function: While traditional SSPC circuits possess current telemetry output capabilities, external current telemetry sampling is typically periodic. When a short-circuit overcurrent event causes protection shutdown, the short-circuit protection circuit's operating time is usually on the order of microseconds, making it difficult for external telemetry to acquire the maximum current value during the short circuit. This results in exceptionally difficult fault diagnosis. This invention designs a maximum current acquisition / storage circuit that actively acquires and latches the maximum current during a short-circuit overcurrent fault, avoiding the drawback of maximum current value loss caused by the periodic sampling characteristics of external telemetry.

[0020] Specifically, such as Figure 1As shown, the present invention proposes an isolated drive control circuit suitable for high-voltage SSPC, comprising: a hard-wired interface circuit 1, an isolated power conversion circuit 2, a drive circuit 3, a current sampling circuit 4, and a temperature sampling circuit 5. The hard-wired interface circuit is electrically isolated from the power circuit. The hard-wired interface circuit is used for external PWM control command input, as well as status telemetry, digital level and analog level output. The digital level output includes switch status indication and protection status indication; the analog level output includes current telemetry signal and temperature telemetry signal. The isolated power conversion circuit is used to convert the power supply voltage, and the converted output voltage is sent to the drive circuit and the current sampling circuit. The drive circuit adjusts the gate voltage according to the external PWM control command input from the hard-wired interface circuit. When the current flowing through the resistor RS in the power circuit is higher than the short-circuit threshold, the drive output is quickly turned off. When a short-circuit event occurs in the power circuit, the drive circuit acquires the maximum current value through the current sampling circuit and latches the maximum current of the current power circuit in real time. The current sampling circuit collects the current value on the resistor Rs in the power circuit. After conditioning by the current sampling circuit, the current value is isolated and output to the hard-wired interface circuit as a current telemetry signal. The temperature sampling circuit integrates a temperature sensor on a chip packaged with an isolated drive control circuit to detect chip temperature and transmits the collected chip temperature to a hard-wired interface circuit as a temperature telemetry signal.

[0021] In this invention, the hard-wired interface circuit, the isolated power conversion circuit, the drive circuit, and the current sampling circuit that make up the isolated drive control circuit are all integrated into one package.

[0022] In this invention, the isolated power conversion circuit uses an external resistor R1 outside the package to adjust the first-stage output voltage. The adjustable range of the first-stage output voltage is +12V to +20V, and the adjustment formula is as follows: U VDD2 =12+k1×R1; In the formula, k1 is the proportionality coefficient, R1 is the external resistance, and U VDD2 This is the first-stage output voltage, U. VDD2 The output is given to the drive circuit and the current sampling circuit.

[0023] In this invention, the secondary side of the isolated power conversion circuit integrates an LDO circuit after the first-stage output voltage to achieve a second-stage power supply voltage conversion. The second-stage output voltages are 5V and 3.3V, which are output to the maximum current acquisition / storage unit and current sampling circuit in the drive circuit.

[0024] In this invention, the drive circuit performs gate voltage regulation control according to the external PWM control command input from the hard-wired interface circuit. When the current flowing through the resistor RS in the power circuit is higher than the short-circuit threshold, the drive output is quickly turned off. When a short-circuit event occurs in the power circuit, the maximum current acquisition / storage circuit is activated. The maximum current acquisition / storage circuit acquires the maximum current value through the current sampling circuit and latches the maximum current of the current power circuit in real time.

[0025] Specifically, the drive circuit includes a switching slope control circuit, a gate voltage regulation control circuit, and a low-pass filter circuit; the switching slope control circuit is used to control the turn-on and turn-off slope of the power MOSFET M1 in the power circuit; the gate voltage regulation control circuit is used to control the first-stage output voltage U. VDD2 The size of the resistor RS is adjusted to adjust the steady-state gate voltage after the power MOSFET M1 is turned on; the low-pass filter circuit is used to filter the pulsating gate voltage level output by the front-stage gate voltage regulation control circuit, thereby achieving the continuity of the OUTH pin voltage output; the power circuit includes a resistor RS and a power MOSFET M1.

[0026] Pulsating gate voltage level V OUTH Its magnitude is controlled by the duty cycle of the PWM waveform, and its mathematical description is as follows: V OUTH =k2×U VDD2 In the formula, k2 is the duty cycle of the PWM waveform, and U VDD2 This is the first-stage output voltage of the isolation converter circuit.

[0027] like Figure 2 As shown, the normal startup process: V at time 0-t1 OUTH According to U VDD2 Full duty cycle output, at this time V OUTH The output voltage and the first-stage output voltage U on the secondary side of the isolated power conversion circuit VDD2 Maintain consistency; The period from t1 to t3 is the controlled adjustment zone, during which V OUTH Operating in an adjustable duty cycle state, the gate voltage VGS of the power MOSFET M1 in the power circuit stabilizes in the Miller plateau period, and the drain-source current I of the power MOSFET M1... DS Slowly rising, I DS The rise time is controlled by the duty cycle. At time t3-t4, V OUTH Restore to U VDD2 As the gate voltage VGS rises rapidly, the MOSFET on-resistance drops quickly to a stable value. The gate voltage VGS remains constant with U during the time intervals t4-t5.VDD2 The output voltage values ​​are consistent.

[0028] Furthermore, the short-circuit turn-off process: when a short-circuit event occurs in the power circuit at time t6, V OUTH The voltage drops rapidly to 0V. At this point, the gate voltage VGS decreases rapidly because the gate charge enters the discharge period due to the lack of drive power. The period from t6 to t9 is the controlled adjustment zone, during which V OUTH Operating in an adjustable duty cycle state, the gate voltage VGS output voltage drops to the Miller plateau period, and the current I... DS The current drops and enters the current-limiting region, thereby suppressing the peak short-circuit current. The time is controlled by the duty cycle. At time t9, I DS When the value drops to 0, the short-circuit shutdown process ends.

[0029] Furthermore, the driving circuit also includes a short-circuit protection circuit and a maximum current acquisition and storage circuit. The short-circuit protection circuit acquires the voltage difference from the resistor RS through the VS terminal and compares it with a set protection threshold. When the voltage difference from the resistor RS is greater than or equal to the set protection threshold, it outputs a signal to the gate voltage regulation control circuit, which then performs a rapid turn-off action on the power MOSFET M1 in the power circuit through the OUTH and OUTL pins. At the same time, the maximum current value flowing through the resistor RS in the power circuit is acquired and stored through the maximum current acquisition and storage circuit.

[0030] Example: like Figure 1 As shown, this embodiment provides an isolated drive control circuit suitable for high-voltage SSPC, including: a hard-wired interface circuit 1, an isolated power conversion circuit 2, a drive circuit 3, a current sampling circuit 4, and a temperature sampling circuit 5. The technical approach for implementing this isolated drive control circuit is chip integration design, which is encapsulated in a single package. The hard-wired interface circuit is electrically isolated from the power circuit. The hard-wired interface circuit realizes 1 control command input and 4 status telemetry outputs, including 2 digital level outputs and 2 analog level outputs. The digital level outputs are switch status indication and protection status indication, respectively; the analog level outputs are current telemetry signal and temperature telemetry signal, respectively. The isolated power conversion circuit and drive control circuit are integrated in one package; the first-stage output voltage can be adjusted via an external resistor R1 outside the package, and the first-stage output voltage can be adjusted between +12V and +20V. The adjustment formula is as follows: U VDD2 =12+k1×R1; In the formula, k1 is the proportionality coefficient, R1 is the external resistance, and U VDD2 This is the first-stage output voltage; The integrated LDO circuit after the primary output voltage on the secondary side of the isolated power converter circuit can realize a two-stage power supply voltage conversion, with secondary output voltages of 5V and 3.3V. The characteristics of the drive circuit are as follows: 1) It features gate voltage regulation and control, integrating a switching slope control circuit, a gate voltage regulation and control circuit, and a low-pass filter circuit. It can adjust the gate voltage by receiving external PWM commands. The gate voltage is controlled by the duty cycle of the PWM waveform, mathematically described as follows: V OUTH =k2×U VDD2 In the formula, k2 is the duty cycle of the PWM waveform, U VDD2 This is the output voltage of the isolation converter circuit; the specific gate voltage adjustment method is as follows: Figure 2 As shown: Normal startup process: From time 0 to t1, the gate voltage output voltage is output according to the full duty cycle of VDD2. At this time, V OUTH The output voltage remains consistent with VDD2; the period from t1 to t3 is the controlled adjustment zone, during which V... OUTH The output voltage operates in an adjustable duty cycle state, the gate voltage VGS stabilizes at the Miller plateau period, and the current I... DS The rise is slow, and the rise time of IDS is controlled by the duty cycle; at time t3-t4, V OUTH The output voltage recovers to VDD2, the gate voltage VGS rises rapidly, and the MOSFET on-resistance drops quickly to a stable value. Short-circuit turn-off process: When a short-circuit event occurs at time t6, V OUTH The output voltage rapidly drops to 0V. At this time, the gate voltage VGS decreases rapidly because the gate charge enters the discharge period due to the lack of drive power supply. The period from t6 to t9 is the controlled adjustment region, during which V... OUTH When the output voltage operates in an adjustable duty cycle state, the gate voltage VGS drops to the Miller plateau period, and the current I... DS The current decreases and enters the current-limiting region, thereby suppressing the peak short-circuit current. The time is controlled by the duty cycle. At time t9, I DS When the value drops to 0, the short-circuit shutdown process ends. 2) It has a short-circuit protection circuit, which can quickly shut down the drive output when the current is higher than the short-circuit threshold; 3) It has the function of maximum current acquisition and storage. When a short circuit event occurs, it will activate the maximum current acquisition and latch the current maximum current in real time. The current sampling circuit acquires the voltage value on the external resistor Rs through the IN+ and IN- pins. After conditioning by the current sampling circuit, the voltage value is isolated and output to the hard-wired interface circuit. The temperature sampling circuit uses an on-chip integrated temperature sensor for on-chip temperature detection and output.

[0031] This invention ingeniously designs a safety isolation drive circuit suitable for high-voltage SSPC solid-state power controllers. This circuit can achieve functions such as starting with a large capacitive load, suppressing peak short-circuit current, and recording the maximum short-circuit current. This invention solves the problems of conventional SSPC drive circuits, such as the non-adjustable gate voltage control voltage, uncontrolled peak short-circuit current under high-voltage applications, and inability to obtain the maximum short-circuit current, greatly improving the safety and intelligence of the drive circuit.

[0032] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. An isolated drive control circuit suitable for high-voltage SSPC, characterized in that, include: Hard-wire interface circuit, isolated power conversion circuit, drive circuit, current sampling circuit, temperature sampling circuit; The hard-wired interface circuit is electrically isolated from the power circuit. The hard-wired interface circuit is used for external PWM control command input, as well as status telemetry, digital level and analog level output. The digital level output includes switch status indication and protection status indication; the analog level output includes current telemetry signal and temperature telemetry signal. The isolated power conversion circuit is used to convert the power supply voltage, and the converted output voltage is sent to the drive circuit and the current sampling circuit. The drive circuit adjusts the gate voltage according to the external PWM control command input from the hard-wired interface circuit. When the current flowing through the resistor RS in the power circuit is higher than the short-circuit threshold, the drive output is quickly turned off. When a short-circuit event occurs in the power circuit, the drive circuit acquires the maximum current value through the current sampling circuit and latches the maximum current of the current power circuit in real time. The current sampling circuit collects the current value across resistor Rs in the power circuit. After conditioning by the current sampling circuit, the current value is isolated and output to the hard-wired interface circuit as a current telemetry signal. The temperature sampling circuit integrates a temperature sensor on a chip packaged with an isolated drive control circuit to detect chip temperature and transmits the collected chip temperature to a hard-wired interface circuit as a temperature telemetry signal.

2. The isolation drive control circuit suitable for high-voltage SSPC according to claim 1, characterized in that: The hard-wired interface circuit, isolated power conversion circuit, drive circuit, and current sampling circuit that make up the isolated drive control circuit are all integrated into one package.

3. The isolation drive control circuit suitable for high-voltage SSPC according to claim 2, characterized in that: The isolated power conversion circuit uses an external resistor R1 outside the package to adjust the first-stage output voltage. The adjustable range of the first-stage output voltage is +12V to +20V, and the adjustment formula is as follows: IN VDD2 =12+k1×R1; In the formula, k1 is the proportionality coefficient, R1 is the external resistance, and U VDD2 This is the first-stage output voltage, U. VDD2 The output is given to the drive circuit and the current sampling circuit.

4. An isolated drive control circuit suitable for high-voltage SSPC according to claim 2 or 3, characterized in that: The isolated power conversion circuit integrates an LDO circuit after the primary output voltage on the secondary side, realizing a two-stage power supply voltage conversion. The secondary output voltages are 5V and 3.3V, which are output to the maximum current acquisition / storage unit and current sampling circuit in the drive circuit.

5. The isolation drive control circuit suitable for high-voltage SSPC according to claim 3, characterized in that: The driving circuit includes a switching slope control circuit, a gate voltage regulation control circuit, and a low-pass filter circuit; the switching slope control circuit is used to control the turn-on and turn-off slope of the power MOSFET M1 in the power circuit; the gate voltage regulation control circuit is used to control the first-stage output voltage U. VDD2 The size of the resistor RS is adjusted to adjust the steady-state gate voltage after the power MOSFET M1 is turned on; the low-pass filter circuit is used to filter the pulsating gate voltage level output by the front-stage gate voltage regulation control circuit, thereby achieving the continuity of the OUTH pin voltage output; the power circuit includes a resistor RS and a power MOSFET M1.

6. The isolation drive control circuit suitable for high-voltage SSPC according to claim 5, characterized in that: Pulsating gate voltage level V OUTH Its magnitude is controlled by the duty cycle of the PWM waveform, and its mathematical description is as follows: In OUTH =k2×U VDD2 In the formula, k2 is the duty cycle of the PWM waveform, and U VDD2 This is the first-stage output voltage of the isolation converter circuit.

7. The isolation drive control circuit suitable for high-voltage SSPC according to claim 5, characterized in that: Normal startup process: V at time 0-t1 OUTH According to U VDD2 Full duty cycle output, at this time V OUTH The output voltage and the first-stage output voltage U on the secondary side of the isolated power conversion circuit VDD2 Maintain consistency; The period from t1 to t3 is the controlled adjustment zone, during which V OUTH Operating in an adjustable duty cycle state, the gate voltage VGS of the power MOSFET M1 in the power circuit stabilizes in the Miller plateau period, and the drain-source current I of the power MOSFET M1... DS Slowly rising, I DS The rise time is controlled by the duty cycle. At time t3-t4, V OUTH Restore to U VDD2 As the gate voltage VGS rises rapidly, the MOSFET on-resistance drops quickly to a stable value. The gate voltage VGS remains constant with U during the time intervals t4-t5. VDD2 The output voltage values ​​are consistent.

8. The isolation drive control circuit suitable for high-voltage SSPC according to claim 7, characterized in that: Short-circuit turn-off process: When a short-circuit event occurs in the power circuit at time t6, V OUTH The voltage drops rapidly to 0V. At this point, the gate voltage VGS decreases rapidly because the gate charge enters the discharge period due to the lack of drive power. The period from t6 to t9 is the controlled adjustment zone, during which V OUTH Operating in an adjustable duty cycle state, the gate voltage VGS output voltage drops to the Miller plateau period, and the current I... DS The current drops and enters the current-limiting region, thereby suppressing the peak short-circuit current. The time is controlled by the duty cycle. At time t9, I DS When the value drops to 0, the short-circuit shutdown process ends.

9. The isolation drive control circuit suitable for high-voltage SSPC according to claim 4, characterized in that: The driving circuit also includes a short-circuit protection circuit and a maximum current acquisition and storage circuit. The short-circuit protection circuit acquires the voltage difference from the resistor RS through the VS terminal and compares it with the set protection threshold. When the voltage difference from the resistor RS is greater than or equal to the set protection threshold, it outputs a signal to the gate voltage regulation control circuit, which then performs a fast turn-off action on the power MOSFET M1 in the power circuit through the OUTH and OUTL pins. At the same time, the maximum current value flowing through the resistor RS in the power circuit is acquired and stored through the maximum current acquisition and storage circuit.

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