A Digital Timing-Mismatch Calibration Technique for Time-Interleaved ADCs Based on a Coordinate Rotational Digital Computer Algorithm

Abstract

Timing-mismatch errors among channels in time-interleaved analog-to-digital converters (TIADCs) greatly degrade the whole performance of the system. Therefore, techniques for calibrating timing mismatch are indispensable, and a new fully-digital calibration technique is presented in this article. Based on a Hilbert filter, modified moving averagers (MMAs) and inverse cosine functions, the proposed estimation algorithm is fast (within 1200 sample points) and accurate. Meanwhile, the coordinate rotational digital computer (CORDIC) algorithm, which is used to implement inverse cosine functions, is also improved, giving it higher precision. In addition, a compensation method based on second-order Taylor series approximation with less hardware resource consumption is provided. Through analyses and simulations, this calibration technique proved to be suitable for TIADCs with an arbitrary number of channels, in which the signal-to-noise and distortion ratio (SNDR) and the spurious-free dynamic range (SFDR) were, respectively, improved from 24.06 dB and 24.57 dB to 67.96 dB and 85.69 dB.

An All-Digital Timing Mismatch Calibration Algorithm Based on Reference Channel for TIADC

“…Relative to the calibration methodologies that have been recently reported by our group, the algorithm in this article shows significant advantages [30,31]. In contrast to the approach in Ref.…”

“…In contrast to the approach in Ref. [30], the feedback architecture is employed to approximate the parameters to the actual values, despite inherent stability concerns. By utilizing a feedforward calibration structure, this paper systematically enhances the stability and improves the entire performance of the calibration process.…”

“…The calibration structures in Refs. [30,31] present limited efficacy in the multi-frequency signals calibration, therefore imposing significant constraints on their practical applications. In contrast, the calibration architecture in this paper demonstrates the superior effectiveness in the context of the multi-frequency signals calibration.…”

Static and Dynamic Analysis of Coupled Vibration of Suspension Bridge Structure Under Earthquake Action

“…In terms of dynamic analysis, modal analysis and time history analysis [32] were used to analyze the dynamic response of the suspension bridge. The dynamic response of the suspension bridge was calculated and analyzed under different seismic waves.…”

A Novel Fully Digital Feedforward Background Calibration Technique for Timing Mismatch in M-Channel Time-Interleaved ADCs

“…In the above discussion, we assume that both offset and gain mismatches were calibrated before timing mismatch calibration by our proposed technique. However, offset and gain mismatches cannot be completely eliminated in practice [11,28]. To view the effectiveness of our calibration algorithm even in the presence of the three mismatches (i.e., offset, gain and timing mismatches), we set the offset mismatch = [0, 0.0001, −0.0002, 0.0002] and gain mismatch = [1, 1.0001, 1.0001, 0.9998].…”