A Novel Mash-Kind Third-Order ΣΔ Converter Structure

This paper presents a novel sigma-delta modulator architecture dedicated to very low-power applications where in third-order noises haping is achieved with very modest constraints on the analog part. The architecture is based on an enhanced MASH structure where the feedback of every loop is the sum of its output and of the output of the following loops. <br><br> The analytical model of the architecture is introduced and it is shown that the proposed architecture offers performance comparable to other third order cascaded sigma-delta modulator topologies with an analog part that is two times smaller than the one of a conventional MASH structure. <br><br> Computer simulations confirm the theoretical calculations made with this structure. The chip layout of a ultra low-power 16-bit audio D–A converter using this modulator is presented. The expected power consumption of the converter is only 125 µW with a power supply of 1.8 V.