A 0.02-mm $^{2}$ 9-Bit 50-MS/s Cyclic ADC in 90-nm Digital CMOS Technology

A 9-bit cyclic ADC employs a track-and-evaluation technique for enhancing the speed of residue evaluation. The proposed multiply-by-two circuit has a shorter evaluation time than the conventional design due to the application of a partial positive feedback topology. The residue evaluation and sampling phases are merged to reduce the conversion latency. Hence, only four clock cycles are required to perform the 9-bit conversion. The proposed 0.02-mm² ADC has been fabricated in 90-nm digital CMOS technology. It operates at 50 MS/s and achieves an SNDR of 50.5 dB with a power consumption of 6.9 mW from a 1.0-V supply.