Calibration and Correction of Timing Mismatch Error in Two-Channel Time-Interleaved DACs

摘要

Time interleaving can be applied to digital-to-analog converters (DACs) to cancel the image replicas in the DAC's output spectrum. However, mismatches among the sub-DAC channels would render the cancellation of the image replicas incomplete and thus degrading the time-interleaved DAC's (TIDAC's) performance. In this paper, we considered the timing mismatch in a two-channel summing TIDAC and proposed a pre-filter correction technique for cancelling the image replica in the frequency band [0,f_s/2] where f_s is the TIDAC sampling rate. A calibration method which measures the parameters needed for the correction filter design was also introduced. In our simulated example, the proposed technique was able to demonstrate a 40 dB SFDR improvement.