A 12fJ/conversion-step 8bit 10MS/s asynchronous SAR ADC for low energy radios

This paper presents an 8-bit asynchronous SAR ADC for flexible, low energy radios. The prototype in a 90nm CMOS technology achieves an ENOB of 7.7bit at a sampling frequency of 10.24MS/s while consuming 26.3μW from a 1V supply. Excellent power efficiency is achieved by using asynchronous dynamic logic, custom 0.5fF unit capacitors, a low-complexity design and an optimized layout. The measured prototype achieves a FoM of 12fJ/conversion-step, which is a 2.5x improvement over previous state-of-the-art 8-bit converters. Moreover, the fully dynamic design, which is optimized for low-leakage, leads to a standby power consumption of 6nW.