Continuous-time delta-sigma modulator using vector filter in feedback path to reduce effect of clock jitter and excess loop delay

In this paper, we propose a novel delta-sigma modulator (DSM) that reduces the effects of clock jitter and excess loop delay by using a vector filter in the feedback path. The vector filter divides the input signal into a high-frequency part and a low-frequency part. The low-pass signal is placed in the path to the first-stage digital-to-analog converter for reducing the effects of the clock jitter, and the high-pass signal is placed in the feedback path to the last integrator in order to compensate for the excess loop delay. The DSM using the vector filter in the feedback path (DSM-VF) is verified using MATLAB/Simulink. Further, a clock jitter (0.1 %) in DSM-VF leads to an improvement in the signal-to-noise-ratio (SNR) to 22.5 dB as compared to the SNR of a conventional CTDSM. Moreover, the SNR deterioration caused by the excess loop delay is improved.