This paper describes the design of a Sigma-Delta modulator aimed for A/D conversion in xDSL applications, featuring 14-bit@4Msample/s in a 0.35μm mainstream digital CMOS technology. Architecture selection, modulator sizing and cell sizing tasks where supported by a CAD methodology, thus allowing us to obtain a power efficient implementation in a short design cycle.This work has been supported by the ESPRIT Project 29261 MIXMODEST.Peer reviewed