A 1-GS/s 11-b Time-Interleaved SAR ADC With Robust, Fast, and Accurate Autocorrelation-Based Background Timing-Skew Calibration
Mingyang Gu, Yunsong Tao, Xiyu He, Yi Zhong, Lu Jie, Nan Sun
Abstract
This work proposes an autocorrelation-based background timing-skew calibration method. It uses the correlations between adjacent channels to extract timing-skew errors, which relaxes the input bandwidth limitation up to the Nyquist frequency. Moreover, the proposed technique simultaneously detects all channels’ timing-skew errors, guaranteeing fast and accurate convergence. This work also proposes a clock booster. It has a simple structure and can efficiently increase the voltage swing of the clock signal. Equipped with the proposed techniques, a 1-GS/s 11-bit four-channel time-interleaved (TI) SAR analog-to-digital converter (ADC) achieves 59.3-dB SNDR and 78.8-dB SFDR with all skew tones below −80 dB at the Nyquist input. The total power dissipation is only 3.7 mW with digital computations implemented off-chip. This corresponds to the Schreier FoM of 170.6 dB and Walden FoM of 4.9 fJ/conv-step.