A 0.033-mm221.5-AF Resolution Continuous-Time Delta-Sigma Capacitance-To-Digital Converter with Parasitic Capacitance Immunity up to 480pF

Hyeyeon Lee, Changuk Lee, Jae Youl Lee, Yoon Kyung Choi, Youngcheol Chae

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

Abstract

Smart devices incorporating 3D hover or fingerprint sensor require a high-resolution capacitance-To-digital converter (CDC) to detect very small changes in capacitance of only tens of aF [1]. Although the switched-capacitor (SC) delta-sigma (ΔΣ) CDCs have accomplished high resolution [2], [3], the SC ΔΣ CDCs suffer from sampling noise penalty and are prone to an input parasitic capacitor (CP). In addition to the resolution, the CDCs in the systems are designed for low power consumption and small areas, considering integration in mobile devices. The current conveyor front-end is proposed in [1] and effectively isolates the CP from the following ADC, resulting in high energy efficiency. However, the work in [1] achieved a limited CP immunity (only 30pF) and is sensitive to high-frequency interference due to the limitation of SC ΔΣ CDCs. In this work, a continuous-Time (CT) ΔΣ CDC, which consists of a class-AB current conveyor and a CT ΔΣ ADC, is proposed. Implemented in a small area of 0.033mm2, it achieves 21.5-pF resolution with a high CP immunity of 480pF and a tolerance to high-frequency interference.

Original languageEnglish
Title of host publicationProceedings - A-SSCC 2021
Subtitle of host publicationIEEE Asian Solid-State Circuits Conference
PublisherInstitute of Electrical and Electronics Engineers Inc.
ISBN (Electronic)9781665443500
DOIs
Publication statusPublished - 2021
Event2021 IEEE Asian Solid-State Circuits Conference, A-SSCC 2021 - Busan, Korea, Republic of
Duration: 2021 Nov 72021 Nov 10

Publication series

NameProceedings - A-SSCC 2021: IEEE Asian Solid-State Circuits Conference

Conference

Conference2021 IEEE Asian Solid-State Circuits Conference, A-SSCC 2021
Country/TerritoryKorea, Republic of
CityBusan
Period21/11/721/11/10

Bibliographical note

Publisher Copyright:
© 2021 IEEE.

All Science Journal Classification (ASJC) codes

  • Hardware and Architecture
  • Signal Processing
  • Electrical and Electronic Engineering

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