Distributed virtual-ground switching for sar and pipelined adc

Abstract

Systems, apparatuses, and methods are provided for analog-to-digital converters (ADCs), such as successive-approximation-register (SAR) ADCs and pipelined ADCs that utilize distributed virtual-ground switching (DVS). DVS circuits and systems receive reference signal inputs that are provided to input signal buffers at the input side of the buffers via reference switches. The input signal buffers and corresponding switches are distributed into scaled replicas that each receive an analog input signal via input signal switches during a first operational phase and are connected to top plates of corresponding distributed capacitors. The bottom plates of the capacitors are sampled to provide analog input signal representations. Based on the value of the signal representations, a state machine controls each of the switches to apply reference signals to the input buffers, during a second operation phase, and to iteratively generate additional signal representations and provide a digital signal that corresponds to the analog input signal.