An ultra-low-power extended counting ADC For large scale sensor arrays

In this paper, an ultra-low-power area-efficient 12-bit extended counting analog-to-digital conversion (EC-ADC) is presented. A double-sampling configuration for incremental ΣΔ modulators is proposed to halve the clock frequency of EC-ADC for the same conversion accuracy and rate. A class-AB operational transconductance amplifier (OTA) for low power EC-ADC is developed. The proposed architecture has been implemented using a commercial 0.18μm CMOS technology and occupies an area of 0.036mm². Measured results show that a power consumption of 13μW can be achieved at the conversion rate of 50Ksamples/s and 10.2-bit accuracy respectively.