Integrated 0.9 V charge-control switching converter with self-biased current sensor

A charge-control non-inverting flyback converter that works in pseudo-continuous conduction mode is presented. Charge control is realized through the introduction of an integrated self-biased current sensor for fast response with a fully-matched structure for accuracy down to the mA range. The topology allows an output voltage of 1.2 V to be derived from a supply voltage of 1.5 V down to 0.9 V. The integrated converter is designed in a standard 0.18 /spl mu/ CMOS process. It switches at 500 kHz and exhibits excellent line-to-load transient response, with an efficiency of 91.3% at a load current of 200 mA.