Correct application wiring diagram of HL402 in high frequency field

In high-frequency applications, the application circuit that can block the input signal
when soft shutdown occurs is shown in Figure 12-51. In the figure, LM555 is set to "1" when the power is turned on and the input signal is mine. .
Enter pins 17 and 16 of HL402 through the 4081 AND gate. When soft shutdown occurs, the optocoupler
VL is turned on, the transistor V is turned off, and the v, collector voltage is delayed by 5ys through the iOkCL resistor and 330pF capacitor, causing the LM555 to be set to ".", and the input signal is blocked
through the 4081 AND gate.
, this circuit delays the sre.s action in order to make the IGBT soft-turn off before stopping
the input signal, to avoid hard turn-off caused by immediately stopping the input signal . In the figure, C,,C. The typical value is
䉉iFcF. C:,C. For iOOyF/25V, VD. , VD, optional o—sv. It is used as a drive circuit in a power electronic converter system where
the rate device is IGBT to complete the optimal drive of the IGBT and prevent IGBT breakdown damage. This article lists several examples to illustrate its application in power electronic converter systems.