SN6505A-Q1 and SN6505B-Q1 devices support soft-start feature. Upon power up or when EN pin transitions from Low to High, the gate drive of the output power-MOSFET is gradually increased over a period of time from 0 V to V_CC. Soft-start prevents high inrush current from V_CC while charging large secondary side decoupling capacitors, and also prevents overshoot in secondary voltage during power-up. For applications that need quick power-up, the SN6505D-Q1, that has soft-start disabled, can be used.