A 10b 20MS/s SAR ADC with a low-power and area-efficient DAC-compensated reference

M. Liu, A.H.M. van Roermund, P.J.A. Harpe

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

10 Citations (Scopus)
4 Downloads (Pure)


Reference drivers for charge-redistribution SAR ADCs require significant area and/or power. In this work, a low-power and area-efficient passive reference-voltage driving scheme for charge-redistribution SAR ADCs is proposed. An on-chip decoupling capacitor is pre-charged to a reference voltage during tracking phase and utilized to drive the DAC passively during conversion. The reference-voltage drops during the conversion due to passive charge sharing, causing non-binary DAC switching steps. This is corrected by calculating the charge consumption of critical switching steps and compensating this with a compensation DAC. This scheme with 3b compensation is utilized in a 10b 20MS/s SAR ADC fabricated in 65nm CMOS. With a near-Nyquist input tone, the compensation improves the SNDR by 2.7dB and the SFDR by 11.6dB compared to the uncompensated ADC, achieving 55.4dB SNDR and 68.2dB SFDR. The FoM is 15.7fJ/conv.-step including the reference-voltage driver. Moreover, thanks to the compensation, the decoupling capacitor can be reduced to save chip area.
Original languageEnglish
Title of host publication43rd IEEE European Solid State Circuits Conference , ESSCIRC 2017, 11-14 September 2017, Leuven, Belgium
Place of PublicationPiscataway
PublisherInstitute of Electrical and Electronics Engineers
Number of pages4
ISBN (Electronic)978-1-5090-5025-3
ISBN (Print)978-1-5090-5026-0
Publication statusPublished - 2 Nov 2017
Event43rd European Solid State Circuits Conference (ESSCIRC 2017) - Leuven, Belgium
Duration: 11 Sept 201714 Sept 2017
Conference number: 43


Conference43rd European Solid State Circuits Conference (ESSCIRC 2017)
Abbreviated titleESSCIRC 2017
Other47th European Solid-State Device Research Conference (ESSDERC 2017) & 43rd European Solid-State Circuits Conference (ESSCIRC 2017), 11-14 September 2017, Leuven, Belgium
Internet address


  • Area efficient
  • Charge-redistribution
  • Low power
  • Reference-voltage driving


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