MATLAB-Based Modeling and Spectral Analysis of Inter-Channel Mismatch Errors in Time-Interleaved ADCs

Zhendong Wang

doi:10.54691/9mw1h965

Authors

Zhendong Wang School of Navigation and Shipping, Shandong Jiaotong University, Weihai 264200, China

DOI:

https://doi.org/10.54691/9mw1h965

Keywords:

Time-interleaved analog-to-digital converter; inter-channel mismatch; MATLAB modeling; gain mismatch; offset mismatch; timing skew; spectral analysis.

Abstract

Time-interleaved analog-to-digital converters (TIADCs) increase the overall sampling rate by operating multiple sub-ADCs with uniformly shifted sampling phases. However, channel-to-channel differences caused by device variations, analog front-end mismatch, and sampling-clock errors introduce deterministic interleaving spurs that degrade the output spectrum. This paper develops a MATLAB-based numerical model for the three dominant mismatch mechanisms: gain mismatch, offset mismatch, and timing-skew mismatch. A four-channel, 14-bit, 1-GS/s TIADC with 8192 samples is considered. The ideal interleaved sampling sequence is first formulated, after which the three mismatch terms are incorporated into a unified channel-dependent output model. FFT-based analysis is then used to identify the spectral characteristics of each mismatch type. Gain mismatch produces input-frequency-dependent image spurs, offset mismatch generates fixed components associated with the interleaving frequency, and timing skew produces input-dependent images whose amplitudes increase with the input-signal slope. The resulting model provides a controllable simulation platform for analyzing TIADC nonidealities and for supporting subsequent mismatch-estimation and digital-calibration studies.

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References

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