A novel autocorrelation-based timing mismatch C alibration strategy in Time-Interleaved ADCs

Abstract

This paper presents a novel autocorrelation-based strategy for timing mismatch calibration in Time-Interleaved ADCs. Different from common technique, the proposed strategy doesn't let autocorrelation between each channel and the reference channel converge to the peak, but to one of the channels with a certain time interval away from the reference channel. It can accelerate convergence. The interval can be selected with much freedom and easily implemented. Representation of sub-ADC output can be only one-bit without a “dead zone”, thus it can further reduce hardware overhead. It's also independent from offset and gain calibration. Using the proposed strategy in a 2-channel 14-bit 500MS/s TIADC, simulation shows a convergence time of 192ms to 0.1%oTs accuracy under 212.4MHz input and initial 5%oTs timing mismatch.