A DC-DC Converter Using A High Speed Soft-Start Control Circuit

In this paper, a high speed soft-start control circuit is proposed to implement the Current-Mode DC-DC Converter. The time for the soft-start does not depend on the load condition from no load to the maximum load current. The proposed circuit consists of SS(RAMP), VREF(RAMP) and a small differential-voltage generator. The SS(RAMP) is a piecewise linear voltage that has four different ramps. The VREF(RAMP) is a linear ramp voltage. The HSPICE simulation results show that the proposed high speed soft-start control circuit to implement to the Current-Mode DC-DC Converter achieved 150 mu s and has been shortened to 1/50 compared with a commonly available high performance converter which achieves in about 7.5ms.