A flash window ADC for DVS-enabled digital controlled DC-DC converters

This paper presents the design and implementation of an analog-to-digital converter (ADC) aiming at digital controlled DC-DC converters for dynamic voltage scaling (DVS) applications. A flash window ADC with programmable conversion range is introduced. In order to achieve a reasonable yield with an uncorrected ADC, the offset of the comparator in the ADC is optimized. The proposed ADC is implemented in a standard 0.18 μm CMOS technology and is applied in a 1MHz DVS-enabled Buck converter. Experiment results show that the dynamic scaling voltage range of 1.2V-2.8V is obtained with a window size of 320mV. It has high robustness to the PVT variations compare to the conventional delay-line ADC.