UCC21710-Q1 initiates a soft turn-off when the overcurrent and short circuit protection is triggered. When the overcurrent and short circuit fault happens, the power power semiconductor transits from the linear region to the saturation region very fast. The channel current is controlled by the gate voltage. By pulling down the gate voltage with a soft turn off current, the dI/dt of the channel current is controlled by the gate voltage and decreasing in a soft manner, thus the overshoot of the power semiconductor is limited and prevents the overvoltage breakdown. The timing diagram of soft turn-off shows in Figure 7-10.

Figure 8-6 Soft Turn-off