Effects of jitter on continuous time digital systems with granularity reduction

Performing digital signal processing in continuous time can be advantageous for a number of applications like biomedical implants, hearing aids, remote sensors, telecommunications, audio and speech processing. While the inherent advantages of digital implementations with respect to programmability and noise immunity are retained by this kind of signal processing, the power consumption can be much lower and the Signal to Noise Ratio (SNR) can be considerably better than for sampled data systems. The delay elements in continuous time systems must be however implemented as quasi continuous time delay lines. This is a completely different solution compared to sampled data systems and results in higher implementation costs. Furthermore the tolerances of the delay lines, mismatches between the delays of the same stage, and jitter can result in severe degradation of the system performance and must be carefully analyzed. In this contribution the effects of jitter on the signal spectrum as well as on the SNR will be considered in detail.