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A Capacitive Mismatch Calibration Method for SAR ADCs Based on TDC
  • +2
  • Qing Shen,
  • mei Jiang,
  • Junxian Chen,
  • Xinhui He,
  • Xin Wang
Qing Shen
Shenzhen University
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mei Jiang
Shenzhen University

Corresponding Author:[email protected]

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Junxian Chen
Shenzhen University
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Xinhui He
Shenzhen University
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Xin Wang
Shenzhen University
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Abstract

The capacitance mismatch problem limits the accuracy improvement of high-precision SAR ADCs (Successive Approximation Register Analog-to-Digital Converters). To address the capacitance array mismatch in SAR ADCs, this paper proposes a novel capacitor calibration scheme based on the Time-to-Digital Converter (TDC). This scheme achieves calibration accuracy as high as 0.01\% and can be flexibly designed to meet the accuracy requirements of SAR ADCs. Simulation results indicate that the capacitance mismatch issue of a redundant capacitor 13-bit SAR ADC can be completely eliminated, and the effective number of bits (ENOB) can approach the ideal value of 13.18 bits. Additionally, the analog component of this scheme utilizes four inverter chains, two D flip-flops, and four counters, without requiring a large area for auxiliary calibration capacitors.
12 Sep 2023Submitted to Electronics Letters
14 Sep 2023Submission Checks Completed
14 Sep 2023Assigned to Editor
25 Jan 20241st Revision Received
29 Jan 2024Submission Checks Completed
29 Jan 2024Assigned to Editor
29 Jan 2024Review(s) Completed, Editorial Evaluation Pending
29 Jan 2024Editorial Decision: Accept