A soft start-up technique for inrush current limitation in DC-DC converters

In this paper a proposed soft start-up mechanism for limiting the input inrush current is presented. The basic idea behind the soft start-up mechanism involves skipping of the clock pulses of a Charge Pump, which is used to drive the gate of a MOSFET switch in the input path of the converter. The proposed inrush current limitation scheme utilizes mainly active devices making it attractive for on-chip integration. Simulation results in a HV CMOS 180nm technology exhibit a maximum inrush current magnitude of less than 500mA over process-voltage-temperature corners.