A Feedback-Signal Shaping Technique for Multi-Level Continuous-Time Delta-Sigma Modulators with Clock-Jitter

A feedback-signal shaping, called phase shift technique, has been proposed to reduce the sensitivity of continuous-time delta-sigma modulator performance to the jitter in the sampling timing. The technique is applied to the multi-level modulators, and the signal-to-noise ratio (SNR) has been evaluated by simulation using an analog behavior model. It has been found that without the technique, the SNR decreases by 20dB/dec if the standard deviation ó of the jitter is larger than 0.2% that of the sampling period. In contrast, by using this technique, the SNR is kept at an ideal value, even if ó is as large as 5% that of the sampling period.