DC/DC converter startup with frequency ramping

Abstract

Control circuitry controls a boost regulator during a start-up period. The control circuitry may comprise an oscillator for generating a clock signal. The oscillator may be configured for ramping up a frequency of the clock signal in accordance with an voltage to be applied to the oscillator and varied during the start-up period. The control circuit may further include a switching circuit configured for controlling a power switch of the boost regulator in response to the clock signal from the oscillator. The switching circuit can control the power switch to have an on-time which is largely independent of the operating frequency of the oscillator. The voltage to be applied to the oscillator may have the same initial voltage level upon startup of the control circuit, independent of an output voltage of the boost regulator.

Dependencies are inferred from the claim text.