Algorithm based on TDC to estimate and calibrate delay between channels of high-speed data acquisition system

Abstract

As the modern electronic system becomes more complicated, the new situations and works require a data acquisition system with a more accurate time parameter. Time delay between channels of high-speed data acquisition system is an important time parameter to estimate and adjust. In high-speed data acquisition system, the ADC data output time is not fixed, and may lead to the delay time of each acquisition channel generated. In order to solve this problem, an algorithm based on TDC is proposed to estimate and calibrate the delay. The algorithm is based on the truth that the sampled data and the data synchronized clock of ADC are synchronized. So phase relationship of the data synchronized clocks can represent the delay between channels. Time-stretched Time-Digital-Converter (TDC) is used to measure the phase difference of the data synchronized clocks. The experiment result proves that the algorithm is faster than four-parameter sine wave fitting, and has a high accuracy up to 100ps.