Calibration on timing skew mismatch in time-interleaved ADCs based on self-adaptive particle swarm algorithm

Abstract The timing skew mismatch is one of the limitations in the Time-interleaved Analog-to-Digital Converter (TIADC) system seriously degrades the system performance. In order to solve this problem, this paper proposes an algorithm to detect the timing skew mismatch. The self-adaptive Particle Swarm Optimization (SAPSO) algorithm was used to detect the timing skew mismatch in the TIADC system, and the variable delay line (VDL) was used to calibrate the detected timing skew mismatch. For verifying the effectiveness of the proposed algorithm, a 4-channel, 1 GHz and 18 bits TIADC system model with timing skew mismatch is established. The simulation results show that the proposed algorithm significantly improves the performance of the TIADC system, which the Spurious Free Dynamic Range (SFDR) is increased by 61.1 dB on average, the Signal-to-Noise Ratio (SNR) is increased by 59.17 dB on average, and the effective Number of Bits (ENOB) is increased by 9.83 bits on average. Compared with the previous calibration algorithms, the proposed method has the advantages of simple structure, fast detection speed and high accuracy.