A novel digital soft-start circuit for DC-DC switching regulator

A new CMOS-compatible digital soft-start circuit for DC-DC switching regulator is presented in this paper, for which the technical is adopted to eliminate the inrush current and avoid the overshoot of the output voltage. It's fully integrated on chip, so that the external soft-start capacitor is not in need, which leads to the reduction of the required board space and component cost. Hspice simulation shows that, while the system has an output voltage of 1.5V at a load of 6A, the envelop of inductor current increases placidly at approximately 1.43A/ms and output voltage increases about 16mV every cycle.