학술논문

A capacitive mismatch calibration method for SAR ADCs based on TDC
Document Type
article
Source
Electronics Letters, Vol 60, Iss 4, Pp n/a-n/a (2024)
Subject
analogue‐digital conversion
analogue integrated circuits
calibration
Electrical engineering. Electronics. Nuclear engineering
TK1-9971
Language
English
ISSN
1350-911X
0013-5194
Abstract
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) 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.