A Single-Channel, 600Msps, 12bit, Ringamp-Based Pipelined ADC in 28nm CMOS
 
A Single-Channel, 600Msps, 12bit, Ringamp-Based Pipelined ADC in 28nm CMOS ■
 
Jorge Luis Lagos Benites, Jorge Luis Lagos Benites, Jorge Luis Lagos Benites, Benjamin Hershberg, Benjamin Hershberg, Benjamin Hershberg, Ewout Martens, Ewout Martens, Ewout Martens, Piet Wambacq, Piet Wambacq, Piet Wambacq, Jan Craninckx, Jan Craninckx, Jan Craninckx
 
Abstract ■

A pipelined ADC is presented that exploits the low but very constant (over output swing) open-loop gain characteristic of the ring amplifier (ringamp) to achieve high SFDR in low-voltage nanoscale CMOS designs. A dynamic ringamp biasing scheme using CMOS resistors and an active ringamp-based common-mode feedback (CMFB) are also introduced. The implemented prototype achieves 56.3dB SNDR and 69.2dB SFDR at 600Msps, consuming 14.2mW from a 0.9V supply, resulting in a Figure-of-Merit (FoM) of 44.3fJ/conv.-step.