Firstack developed Digitally dynamic advanced active clamping D²A²C technology in the application of rail. This technology can effectively control the current flowing through the TVS, so the clamping voltage is more accurate. Firstack innovatively put forward the digitally dynamic advanced active clamping D²A²C technology. As shown in the figure below, the CLPD processor samples the TVS breakdown current via the CS circuit and controls a digitally controlled current source connected to the gate of the IGBT. When the TVS breakdown current is larger than the set threshold, the CPLD push-pull circuit will turn off the -15V power supply to remove the low-resistance path. According to the breakdown current size, control the size of the digitally controlled current source, so as to regulate the gate voltage as well as the TVS current.