A 15.5-mW 20-GSps 4-bit charge-steering flash ADC

This paper presents a 4-bit 20-GSps time-interleaved flash ADC for an ADC-based high-speed serial-link equalizer. The ADC is designed and simulated in a 65-nm CMOS technology. It dissipates 15.5 mW from a 1-V supply while operating at 20 GSps. Low power consumption is achieved by utilizing charge-steering concept, sharing single reference ladder across all the four interleaved branches, and merging the dynamic latch into the pre-amplifier of the comparator. Results show that for a sinusoidal input frequency of 9.84 GHz with an amplitude of 600 mV_diff, the SNDR of the digital output is 23.9 dB, SFDR is 33.6 dB, and the effective number of bits (ENOB) is 3.67 bits.