A low‐power 10‐bit CCP‐based pipelined ADC using a multi‐level variable current source MDAC and an ultra‐low‐power double‐tail dynamic latch

Abstract

SummaryIn this paper, a low‐power 10‐bit 15‐MS/s opamp‐less pipelined analog‐to‐digital converter (ADC) has been proposed. The circuit is comprised of eight 1.5‐bit/stage MDACs and a 2‐bit backend flash ADC. Each 1.5‐bit/stage structure comprises a CCP‐based MDAC which uses a modified multilevel variable‐current‐source (ML‐VCS) scheme. The modified ML‐VCS CCP structure facilitates its usage in a pipeline ADC structure. Also, the proposed ML‐VCS structure improves the speed behavior as well as the power consumption of a 1.5‐bit/stage CCP‐based MDAC structure. In order to further reduce power consumption, an ultra‐low‐power low‐delay double‐tail dynamic latch has been offered which features high‐speed operation. The suggested ADC is simulated using 180‐nm scaled CMOS technology with a 2‐Vp‐p differential full‐scale input voltage. Hspice simulation results show that the ADC exhibits an SNDR of 60‐dB, an ENOB of 9.67 bits, and the FOM of 0.546 PJ/Conv.step at a Nyquist‐rate input frequency. According to the results, the proposed 10‐bit ADC consumes only 6.7‐mW under a 1.8‐V supply voltage.