Adaptive Non-Inverting Buck-Boost IC with On-Chip Sigma-Delta ADC for Portable Applications

This paper focuses on a mixed-signal IC realization of a digitally controlled power converter which steps up/down from 2.7-5.5 V to 1-3.6 V for battery powered portable applications. In particular, in this work a \u3a3-\u394 modulated digital pulse-width modulator is combined with a low power second-order multi-bit \u3a3-\u394 ADC in a 0.5 \u3bcm CMOS process. It is shown that precise output voltage positioning in buck, boost and buck/boost transition modes can be achieved. The quiescent current consumption of the IC is 700 \u3bcA. Experimentally observed efficiency of the converter is reported for 30 mA-360 mA load current with peak efficiency of 94%