To eliminatethe three main mismatch errors of themulti-channel time-interleavedanalog-to-digitalconverter (TIADC)

which are offset mismatch errorbetweenchannel

channel gain mismatch error and sampling time mismatch errorof channel

a background calibration algorithmfor in chip digital circuits isproposed.By adding a way of reference ADC and statistical accumulation

the algorithms perform correlation operation on the output of the calibrated channel and reference channel in order to extract the error information in the background

and then iterates compensation for the mismatch errors through the analog circuit

so as to achieve the purpose of calibration.The algorithm is applied to the 12 bits 3 GS/s four channels TIADC model circuit.When the normalized frequency of input signal is /=0.16569

after calibration

the ENOB and SNR increase from 4.176 5 bits and 26.812 8 dB to 11.699 3 bits and 72.102 3 dB

respectively

and the calibration effect is obvious.In addition

the algorithm is not strictly limited to input signal type

input frequency and inter channel calibration order

and can be extended to any number of channels.