A 13b SAR ADC with eye-opening VCO based comparator

Research output: Chapter in Book/Report/Conference proceedingConference contribution

32 Citations (Scopus)


A low-power and high accuracy comparator based on voltage controlled ring-oscillator (VCO) is presented. By using the dead zone of phase detector effectively, the VCO comparator automatically changes its noise level depending on the input voltage level (Δvin). When Δvin is large, the comparator operates as a low-power delay-line based comparator. On the other hand, when Δvin is small, the VCO is enabled and eye is opened during the oscillation. This suppress input referred noise and enables accurate conversion. The number of oscillation cycle for one comparison is inversely proportional to Δvin and adaptive noise reduction is realized. The VCO comparator does not require any sort of tuning. A 13b SAR ADC with proposed VCO based comparator was fabricated in 65-nm CMOS. By off-chip LMS calibration, the ADC achieves SNDR 66 dB at 1 MS/s with FoM of 29fJ/conv.-step.

Original languageEnglish
Title of host publicationESSCIRC 2014 - Proceedings of the 40th European Solid-State Circuit Conference
EditorsPietro Andreani, Andrea Bevilacqua, Gaudenzio Meneghesso
PublisherIEEE Computer Society
Number of pages4
ISBN (Electronic)9781479956944
Publication statusPublished - 2014 Oct 31
Event40th European Solid-State Circuit Conference, ESSCIRC 2014 - Venezia Lido, Italy
Duration: 2014 Sept 222014 Sept 26

Publication series

NameEuropean Solid-State Circuits Conference
ISSN (Print)1930-8833


Other40th European Solid-State Circuit Conference, ESSCIRC 2014
CityVenezia Lido

ASJC Scopus subject areas

  • Hardware and Architecture
  • Electrical and Electronic Engineering


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