Improving the efficiency of a 2∶1 SC DC-DC converter using the parasitic capacitances

Switched capacitor (SC) DC-DC converters can be used to convert an input voltage range into a fixed output voltage value. The efficiency of these circuits depends on the ratio between the input and output voltages and on the parasitic capacitances of the circuit. Depending on the type of capacitor and how it is connected, the impact of the parasitic capacitances on the efficiency can vary. This paper presents an analysis of the efficiency of the 2:1 SC DC-DC converter as function of the power level and of the parasitic capacitances. This analysis shows that depending on the required power level, different types of capacitors should be used in order to maximize the efficiency of the converter.