On the synthesis of cascaded continuous-time /spl Sigma//spl Delta/ modulators

This paper introduces a new method for synthesis of high-order cascaded continuous time /spl Sigma//spl Delta/-modulators. A simple discrete time to continuous time (DT/CT) equivalence applied previously only to single loop modulators is extended and employed in cascaded CT /spl Sigma//spl Delta/-modulators. The method converts the DT loop-filter to a CT counterpart working with the same digital cancellation logic. Here the synthesis of a 3/sup rd/ order continuous time SOFO modulator is presented. Some nonidealities are analyzed, both analytically and by simulation.