JAJSR77 September 2023 UCC21738-Q1
PRODUCTION DATA
The UCC21738-Q1 initiates a soft turn-off when the overcurrent and short circuit protection are triggered, or when the RST/EN is pulled low for longer than tRSTPD. When the overcurrent and short circuit faults occur, the power semiconductor transitions from the linear region to the saturation region very quickly. The gate voltage controls the channel current. 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 decreases softly; thus, overshooting the power semiconductor is limited, preventing overvoltage breakdown. Figure 7-10 shows the the soft turn-off timing diagram.