A 100-nW 9.1-ENOB 20-kS/s SAR ADC for portable pulse oximeter

Hokyu Lee; Sejin Park; Chaegang Lim; Chulwoo Kim

doi:10.1109/TCSII.2014.2387680

A 100-nW 9.1-ENOB 20-kS/s SAR ADC for portable pulse oximeter

Hokyu Lee, Sejin Park, Chaegang Lim, Chulwoo Kim

Research output: Contribution to journal › Article › peer-review

30 Citations (Scopus)

Abstract

This brief presents an energy-efficient 10-bit accuracy with 20-kS/s successive approximation register analog-to-digital converter for portable pulse oximeter. A data-dependent capacitor reset (DDCR) switching scheme for the capacitive digital-to-analog converter (CDAC) to reduce the average switching energy and the number of unit capacitors is proposed and implemented. Compared with the conventional capacitor switching scheme for CDACs, the proposed DDCR switching scheme reduces the average switching energy and the total number of unit capacitors by 97% and 75%, respectively. We achieved a signal-to-noise-and-distortion ratio of 56.5 dB and a spurious-free dynamic range of 64.7 dBc at the Nyquist input frequency. The measured peak differential and integral nonlinearities are 0.44 and 0.58 least significant bit, respectively. The figure of merit is 9.1 fJ/conversion-step. The prototype, fabricated in the 0.11-μm CMOS process, occupies 0.033 mm².

Original language	English
Article number	7001238
Pages (from-to)	357-361
Number of pages	5
Journal	IEEE Transactions on Circuits and Systems II: Express Briefs
Volume	62
Issue number	4
DOIs	https://doi.org/10.1109/TCSII.2014.2387680
Publication status	Published - 2015 Apr 1

Bibliographical note

Publisher Copyright:
© 2004-2012 IEEE.

Keywords

Pulse oximeter
U-Healthcare
analog-to-digital converter
energy efficient
low-power
successive approximation register

ASJC Scopus subject areas

Electrical and Electronic Engineering

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10.1109/TCSII.2014.2387680

Cite this

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abstract = "This brief presents an energy-efficient 10-bit accuracy with 20-kS/s successive approximation register analog-to-digital converter for portable pulse oximeter. A data-dependent capacitor reset (DDCR) switching scheme for the capacitive digital-to-analog converter (CDAC) to reduce the average switching energy and the number of unit capacitors is proposed and implemented. Compared with the conventional capacitor switching scheme for CDACs, the proposed DDCR switching scheme reduces the average switching energy and the total number of unit capacitors by 97% and 75%, respectively. We achieved a signal-to-noise-and-distortion ratio of 56.5 dB and a spurious-free dynamic range of 64.7 dBc at the Nyquist input frequency. The measured peak differential and integral nonlinearities are 0.44 and 0.58 least significant bit, respectively. The figure of merit is 9.1 fJ/conversion-step. The prototype, fabricated in the 0.11-μm CMOS process, occupies 0.033 mm2.",

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PY - 2015/4/1

Y1 - 2015/4/1

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AB - This brief presents an energy-efficient 10-bit accuracy with 20-kS/s successive approximation register analog-to-digital converter for portable pulse oximeter. A data-dependent capacitor reset (DDCR) switching scheme for the capacitive digital-to-analog converter (CDAC) to reduce the average switching energy and the number of unit capacitors is proposed and implemented. Compared with the conventional capacitor switching scheme for CDACs, the proposed DDCR switching scheme reduces the average switching energy and the total number of unit capacitors by 97% and 75%, respectively. We achieved a signal-to-noise-and-distortion ratio of 56.5 dB and a spurious-free dynamic range of 64.7 dBc at the Nyquist input frequency. The measured peak differential and integral nonlinearities are 0.44 and 0.58 least significant bit, respectively. The figure of merit is 9.1 fJ/conversion-step. The prototype, fabricated in the 0.11-μm CMOS process, occupies 0.033 mm2.

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A 100-nW 9.1-ENOB 20-kS/s SAR ADC for portable pulse oximeter

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

Access to Document

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