Adaptive and digital blind calibration of transfer function mismatch in time-interleaved ADCs

In this paper we propose a digital blind calibration scheme for Time-Interleaved ADCs based on transfer function mismatch which corrects gain, time-skew and bandwidth mismatch errors. The estimation of mismatches uses an adaptive filtering structure with a lowpass filter combined to a fractional delay filter. The compensation is based on the development of a matrix approach to cancel the effect of mismatches. The algorithm was tested with a two-channel 14-bits ADCs board connected to a FPGA and the results show the effectiveness of the technique.