Patent ID: 10491111

Abstract:
Circuits and methods are provided for soft-starting a switched-capacitor converter (SCC), so as to limit inrush current at the start-up of the SCC. This is accomplished by using the first power switch of the SCC, i.e., the switch coupled to the input of the SCC, to reduce the voltage provided at the SCC input, such that the full input voltage is not directly applied to the SCC circuitry downstream from the first power switch during the SCC start-up. The reduced voltage provided to the SCC circuitry (other than the first power switch) serves to limit the current drawn by the remainder of the SCC circuit during the SCC start-up. This reduced voltage begins at zero and ramps to the voltage provided at the SCC input. Once the reduced voltage reaches the input voltage level, steady-state operation of the SCC may begin.