CN-121984491-A - Isolation driving control circuit suitable for high-voltage SSPC

CN121984491ACN 121984491 ACN121984491 ACN 121984491ACN-121984491-A

Abstract

An isolated drive control circuit suitable for a high-voltage SSPC comprises a hard wire interface circuit, an isolated power supply conversion circuit, a drive circuit, a current sampling circuit and a temperature sampling circuit. The invention skillfully realizes a safe isolation driving circuit suitable for a high-voltage SSPC solid-state power controller by designing an isolation power supply conversion circuit, a grid voltage regulating circuit, a low-pass filter circuit, a short-circuit protection circuit and a maximum current acquisition/storage circuit, and the circuit can realize the functions of starting with a large capacitive load, inhibiting short-circuit current peak value, recording short-circuit maximum current and the like. The invention solves the problems that the grid voltage control voltage of the conventional SSPC driving circuit is not adjustable, the short-circuit peak current is not controlled under high-voltage application, the short-circuit maximum current cannot be obtained, and the like, and greatly improves the safety and the intelligent degree of the driving circuit.

Inventors

LI HUIYAO
LIU MI
ZHANG ZHIYU
ZHI SHUBO
WANG LI
ZHOU XINSHUN
WANG JUN
LIANG XIANGHUI

Assignees

北京卫星制造厂有限公司

Dates

Publication Date: 20260505
Application Date: 20251223

Claims (9)

1. The isolation driving control circuit suitable for the high-voltage SSPC is characterized by comprising a hard wire interface circuit, an isolation power supply conversion circuit, a driving circuit, a current sampling circuit and a temperature sampling circuit; the hard wire interface circuit is electrically isolated from the power circuit, and is used for external PWM control instruction input, state telemetry, digital level output and analog level output, wherein the digital level output comprises a switch state indication and a protection state indication; the isolated power supply conversion circuit is used for converting power supply voltage, and the voltage output after conversion is sent to the driving circuit and the current sampling circuit; The drive circuit carries out gate voltage regulation control according to an external PWM control instruction input from the hard wire interface circuit, and realizes quick turn-off drive output when the current flowing through the resistor RS by the power circuit is higher than a short circuit threshold value; The current sampling circuit collects the current value on a resistor Rs in the power circuit, and the current value is conditioned by the current sampling circuit and then is isolated and output to the hard wire interface circuit to be used as a current telemetry signal; and the temperature sampling circuit realizes chip temperature detection by integrating a temperature sensor on a chip packaged by the isolation driving control circuit, and transmits the acquired chip temperature to the hard wire interface circuit to serve as a temperature telemetry signal.
2. The isolated drive control circuit for a high voltage SSPC of claim 1, wherein the hard wire interface circuit, the isolated power conversion circuit, the drive circuit, and the current sampling circuit are integrated in a single package.
3. The isolation driving control circuit suitable for the high-voltage SSPC is characterized in that the isolation power supply conversion circuit realizes primary output voltage value adjustment through an external resistor R1 outside the package, the primary output voltage adjustable range is +12V to +20V, and the adjustment relation formula is: U VDD2 =12+k1×R1; In the formula, k1 is a proportionality coefficient, R1 is an external resistor, U VDD2 is a primary output voltage, and the primary output voltage U VDD2 is output to a driving circuit and a current sampling circuit.
4. The isolation driving control circuit suitable for the high-voltage SSPC is characterized in that an LDO circuit is integrated after the secondary side of the isolation power conversion circuit outputs a primary output voltage, so that the secondary conversion of the power voltage is realized, the secondary output voltage is 5V and 3.3V, and the secondary output voltage is output to a maximum current acquisition/storage unit and a current sampling circuit in the driving circuit.
5. The isolation driving control circuit for the high-voltage SSPC according to claim 3, wherein the driving circuit comprises a switching slope control circuit, a grid voltage adjusting control circuit and a low-pass filter circuit, the switching slope control circuit is used for controlling the on and off slopes of a power MOSFET M1 in the power circuit, the grid voltage adjusting control circuit is used for adjusting the first-stage output voltage U VDD2 and then adjusting the steady-state grid voltage after the power MOSFET M1 is turned on, the low-pass filter circuit is used for filtering the pulsating grid voltage level output by the front-stage grid voltage adjusting control circuit so as to realize the continuity of output voltage of an OUTH pin, and the power circuit comprises a resistor RS and the power MOSFET M1.
6. The isolated drive control circuit for a high voltage SSPC of claim 5, wherein the magnitude of the pulsating gate voltage level V OUTH is controlled by the duty cycle of the PWM waveform, as described mathematically as follows: V OUTH =k2×U VDD2 where k2 is the duty cycle of the PWM waveform, and U VDD2 is the primary output voltage of the isolated conversion circuit.
7. The isolated drive control circuit for a high voltage SSPC of claim 5, wherein the normal start-up process is that V OUTH is output according to the full duty cycle of U VDD2 at time 0-t1, and the output voltage of V OUTH is consistent with the primary output voltage U VDD2 on the secondary side of the isolated power conversion circuit; the time t1-t3 is a controlled adjusting area, V OUTH at the moment works in an adjustable duty ratio state, the grid voltage VGS of a power MOSFET M1 in a power circuit is stabilized in a Miller stage, the drain-source current I DS of the power MOSFET M1 is slowly increased, and the increasing time I DS is controlled by the duty ratio; At time t3-t4, V OUTH is restored to U VDD2 voltage, the gate voltage VGS rises rapidly, and the MOSFET on-resistance drops rapidly to a stable value; the gate voltage VGS at time t4-t5 is maintained to be consistent with the value of the output voltage of U VDD2 .
8. The isolated drive control circuit for a high voltage SSPC of claim 7, wherein the short-circuit shutdown process is a short-circuit event in the power circuit at time t6, wherein V OUTH drops rapidly to 0V, and the gate voltage VGS drops rapidly due to the non-drive supply of gate charge into the discharge phase; the time t6-t9 is a controlled adjustment area, at this time, V OUTH works in an adjustable duty ratio state, the output voltage of the grid voltage VGS is reduced to a Miller stage, the current I DS is reduced, and the current I DS enters a current limiting area, so that the peak value inhibition of short-circuit current is realized, and the time is controlled by the duty ratio; at time t9, I DS drops to 0 and the short-circuit shutdown process ends.
9. The isolation driving control circuit suitable for the high-voltage SSPC is characterized by further comprising a short-circuit protection circuit and a maximum current acquisition and storage circuit, wherein the short-circuit protection circuit equivalently acquires voltage differences from two ends of a resistor RS through a VS end and compares the voltage differences with a set protection threshold, when the voltage differences from two ends of the resistor RS are larger than or equal to the set protection threshold, an output signal is sent to a grid voltage regulation control circuit, then quick turn-off action of a power MOSFET M1 in a power circuit is completed through OUTH and OUTL pins, and meanwhile, the maximum current value of the resistor RS flowing through the power circuit is acquired and stored through the maximum circuit acquisition and storage circuit.

Description

Isolation driving control circuit suitable for high-voltage SSPC Technical Field The invention relates to an isolation driving control circuit suitable for a high-voltage SSPC, and belongs to the technical field of electronics. Background The high-voltage SSPC adopts a high-voltage-resistant power tube as a core control switch, is widely applied to various fields at present, and has the advantages of no contact, no arc, no noise, quick response, small electromagnetic interference, long service life, high reliability and the like. The power tube works at a high side and works in a non-switching state when in steady state, and isolation driving is needed when the power tube is used. The grid voltage of the traditional SSPC isolation driving circuit is not adjustable, the amplitude is generally dependent on the power supply voltage of a driver, the switching process of the SSPC is required to be characterized by being slow in switching performance, in order to achieve the characteristic, the driving circuit is generally designed to be constant voltage output or constant current output, the constant voltage output circuit is used for achieving the slow switching performance of a power MOSFET, the main means is to slow the rising time of the grid voltage of the power MOSFET by increasing the RC delay time between grid voltage output and MOSFET grid electrodes or increasing the Miller capacitance of the MOSFET, the constant current output mode is used for achieving the slow switching performance by changing the charging current of the grid charge, the former is required to rely on a large capacitance and a high withstand voltage capacitance in order to achieve large delay, the high voltage SSPC is required to be used for improving the high voltage withstand performance in a serial multi-capacitance mode, the circuit scale is large, the circuit is not easy to miniaturize, the constant current output mode is required to control the charging current of the grid electrode to be small enough in order to achieve the control of the switching slope, the non-switching interval time of the grid charge curve is prolonged in proportion, and the switching response characteristic is poor. Although the traditional SSPC circuit has a current telemetry output function, because the external current telemetry sampling is usually periodic, when the protection is turned off due to a short-circuit overcurrent event of a circuit, the action time of the short-circuit protection circuit is usually of the order of us, and the external telemetry is difficult to collect the maximum current value during short-circuit, so that the fault investigation process is extremely difficult. Disclosure of Invention The invention solves the technical problems of overcoming the defects of the prior art, providing a brand new drive control circuit, solving the problems of uncontrollable gate drive voltage and uncontrollable maximum current acquisition during short circuit of the SSPC drive control circuit in the prior art, and solving the problem of overlarge size based on an on-chip integration technology. The technical scheme of the invention is as follows: an isolation driving control circuit suitable for 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; the hard wire interface circuit is electrically isolated from the power circuit, and is used for external PWM control instruction input, state telemetry, digital level output and analog level output, wherein the digital level output comprises a switch state indication and a protection state indication; the isolated power supply conversion circuit is used for converting power supply voltage, and the voltage output after conversion is sent to the driving circuit and the current sampling circuit; The drive circuit carries out gate voltage regulation control according to an external PWM control instruction input from the hard wire interface circuit, and realizes quick turn-off drive output when the current flowing through the resistor RS by the power circuit is higher than a short circuit threshold value; The current sampling circuit collects the current value on a resistor Rs in the power circuit, and the current value is conditioned by the current sampling circuit and then is isolated and output to the hard wire interface circuit to be used as a current telemetry signal; and the temperature sampling circuit realizes chip temperature detection by integrating a temperature sensor on a chip packaged by the isolation driving control circuit, and transmits the acquired chip temperature to the hard wire interface circuit to serve as a temperature telemetry signal. Further, the hard wire interface circuit, the isolated power supply conversion circuit, the driving circuit and the current sampling circuit which form the isolated driving control circuit are integrated in one pack