Patent ID: 7199563

Claim:
A DC-DC converter, comprising: (a) a pre-processing circuit with a first input for a DC input voltage, a second input for a reference voltage, an output for a first terminal of an inductor, and a first switch between said output for a first terminal and said input for a DC input voltage; (b) a booster circuit with an input for a second terminal of said inductor, an output for a DC output voltage, and a second switch between said input for a second terminal and a ground; (c) wherein when said DC input voltage is less than said reference voltage, said pre-processing circuit is operable to maintain said first switch as conductive and when said DC input voltage is greater than said reference voltage said pre-processing circuit is operable to control said first switch to have said reference voltage equal to a lowpass-filtered voltage at said output for a first terminal; and (d) wherein said reference voltage is less than said DC output voltage and said booster circuit is operable to control said second switch to generate said DC output voltage from output of said pre-processing circuit when an inductor is connected between said output for a first terminal and said input for a second terminal.