A 12 b 53 mW 195 MS/s Pipeline ADC with 82 dB SFDR Using Split-ADC Calibration

A 12 bit pipeline ADC with residue amplifiers calibrated for gain and distortion is presented. The settling accuracy of the residue amplifiers was lowered to achieve higher energy efficiency and the resulting errors were corrected in multiple stages using a split-ADC calibration technique. Starting from a typical op amp implementation, the settling accuracy of the residue amplifier was relaxed by a factor of more than 3× in the first two stages and by 2× in the remaining stages. The ADC was implemented in 40 nm digital CMOS and shows a Schreier figure-of-merit of 157.5 dB at 1 V supply, sampling at 195 MS/s, with an SNDR/SFDR of 64.8 dB/82 dB. While working in continuous background mode, the split-ADC calibration improved the ADC SFDR by 37 dB within 70,000 samples.