Return to-zero feedback insertion in a continuous time Delta-Sigma modulator for excess loop delay compensation

Abstract

Excess loop delay in continuous time (CT) Delta-Sigma modulators (DSM), as a result of the limited DAC response time, leads to SNR degradation so that the optimal tuning of the system will be impossible. In order to solve this problem, this paper proposes a novel return to-zero feedback insertion method. To verify the analytical results extracted in this paper, a second order CT DSM is simulated.