A 10b 50MS/s Opamp-Sharing Pipeline A/D With Current-Reuse OTAs

A 10b opamp-sharing pipeline A/D using current-reuse OTAs is presented. The current-reuse OTA, with two NMOS differential inputs operating in opposite phases, facilitates opamp-sharing between consecutive stages, minimizing power consumption. Constant transistor biasing ensures no loss of settling time from power-on delays. The AID is fabricated in a 0.18 mu m CMOS process and occupies active area of 0.7mm(2). At 50MS/s, maximum SNDR of 58dB (ENOB=93b) is obtained with 9.2mW analog power consumption on a 1.8V supply.