A 16.8 fJ/c-s 8 b 500 MS/s Asynchronous Three-Comparator SAR ADC With Background Comparator-Swapping Offset Calibration in 28 nm CMOS LPP

This paper presents a novel comparator-swapping background offset calibration method for SAR ADCs, addressing the limitations of previous calibration techniques. The proposed method uses three comparators to eliminate reset time and calibrates offset mismatch based on the LSB conversion, leading to...

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Main Authors: Seunghyun Kim, Yang Azevedo Tavares, Sewon Lee, Minjae Lee
Format: Article
Language:English
Published: IEEE 2025-01-01
Series:IEEE Access
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Online Access:https://ieeexplore.ieee.org/document/10964235/
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author Seunghyun Kim
Yang Azevedo Tavares
Sewon Lee
Minjae Lee
author_facet Seunghyun Kim
Yang Azevedo Tavares
Sewon Lee
Minjae Lee
author_sort Seunghyun Kim
collection DOAJ
description This paper presents a novel comparator-swapping background offset calibration method for SAR ADCs, addressing the limitations of previous calibration techniques. The proposed method uses three comparators to eliminate reset time and calibrates offset mismatch based on the LSB conversion, leading to rapid offset convergence and reduced dependence on input signal statistics. By alternating the roles of the comparators and eliminating the need for an additional calibration cycle, the method achieves efficient calibration without the overhead of extra reference comparators. A prototype 8-bit SAR ADC implemented in a 28 nm CMOS LPP process demonstrates the effectiveness of the proposed technique, achieving a measured SNDR of 44.3 dB and SFDR of 58.4 dB at 500 MS/s, with a power consumption of 1.13 mW. The ADC occupies only 0.0033 mm2, with a Walden FoM of 16.8 fJ/conversion-step. The results show that the proposed calibration method is competitive with state-of-the-art techniques, offering a highly accurate and efficient solution for background offset mismatch calibration in SAR ADCs.
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spelling doaj-art-5fe57095f662411bb02f9f3368db02e42025-08-20T02:18:24ZengIEEEIEEE Access2169-35362025-01-0113664586646710.1109/ACCESS.2025.356032110964235A 16.8 fJ/c-s 8 b 500 MS/s Asynchronous Three-Comparator SAR ADC With Background Comparator-Swapping Offset Calibration in 28 nm CMOS LPPSeunghyun Kim0https://orcid.org/0009-0001-3253-0028Yang Azevedo Tavares1https://orcid.org/0000-0003-1697-016XSewon Lee2https://orcid.org/0000-0002-6397-7324Minjae Lee3https://orcid.org/0000-0003-1500-1404School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology, Buk-gu, Gwangju, South KoreaSchool of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology, Buk-gu, Gwangju, South KoreaSchool of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology, Buk-gu, Gwangju, South KoreaSchool of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology, Buk-gu, Gwangju, South KoreaThis paper presents a novel comparator-swapping background offset calibration method for SAR ADCs, addressing the limitations of previous calibration techniques. The proposed method uses three comparators to eliminate reset time and calibrates offset mismatch based on the LSB conversion, leading to rapid offset convergence and reduced dependence on input signal statistics. By alternating the roles of the comparators and eliminating the need for an additional calibration cycle, the method achieves efficient calibration without the overhead of extra reference comparators. A prototype 8-bit SAR ADC implemented in a 28 nm CMOS LPP process demonstrates the effectiveness of the proposed technique, achieving a measured SNDR of 44.3 dB and SFDR of 58.4 dB at 500 MS/s, with a power consumption of 1.13 mW. The ADC occupies only 0.0033 mm2, with a Walden FoM of 16.8 fJ/conversion-step. The results show that the proposed calibration method is competitive with state-of-the-art techniques, offering a highly accurate and efficient solution for background offset mismatch calibration in SAR ADCs.https://ieeexplore.ieee.org/document/10964235/ADC based SERDES receiverthree-comparator SAR ADCbackground offset calibrationcomparator-swapping method
spellingShingle Seunghyun Kim
Yang Azevedo Tavares
Sewon Lee
Minjae Lee
A 16.8 fJ/c-s 8 b 500 MS/s Asynchronous Three-Comparator SAR ADC With Background Comparator-Swapping Offset Calibration in 28 nm CMOS LPP
IEEE Access
ADC based SERDES receiver
three-comparator SAR ADC
background offset calibration
comparator-swapping method
title A 16.8 fJ/c-s 8 b 500 MS/s Asynchronous Three-Comparator SAR ADC With Background Comparator-Swapping Offset Calibration in 28 nm CMOS LPP
title_full A 16.8 fJ/c-s 8 b 500 MS/s Asynchronous Three-Comparator SAR ADC With Background Comparator-Swapping Offset Calibration in 28 nm CMOS LPP
title_fullStr A 16.8 fJ/c-s 8 b 500 MS/s Asynchronous Three-Comparator SAR ADC With Background Comparator-Swapping Offset Calibration in 28 nm CMOS LPP
title_full_unstemmed A 16.8 fJ/c-s 8 b 500 MS/s Asynchronous Three-Comparator SAR ADC With Background Comparator-Swapping Offset Calibration in 28 nm CMOS LPP
title_short A 16.8 fJ/c-s 8 b 500 MS/s Asynchronous Three-Comparator SAR ADC With Background Comparator-Swapping Offset Calibration in 28 nm CMOS LPP
title_sort 16 8 fj c s 8 b 500 ms s asynchronous three comparator sar adc with background comparator swapping offset calibration in 28 nm cmos lpp
topic ADC based SERDES receiver
three-comparator SAR ADC
background offset calibration
comparator-swapping method
url https://ieeexplore.ieee.org/document/10964235/
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