A 1.6 GS/s 3.17 mW 6-b passive pipelined binary-search ADC with memory effect canceller and reference voltage calibration

Abstract

A 6-bit high-speed and low-power pipelined binary-search ADC is presented. Over GHz conversion rate is achieved by passive pipeline operation without amplifier. “Memory effect” caused by charge sharing in the passive pipeline operation is cancelled by charge reset and flatness of frequency response of the converter is improved. Memory effect canceller also makes it easy to calibrate reference voltage to each comparator and to enhance SNDR. The prototype ADC fabricated in 40nm-CMOS achieved 29.21 dB SNDR with 1.6 GS/s at supply voltage of 0.9 V. The ADC achieved a FoM of 84.1 fJ/conv.step.