Low Power, Low Area Digital Modulators using Gate Diffusion Input Technique

Abstract

Audio playback devices like IPODs and MP3 players use Sigma Delta Digital to Analog Converters (DACs) where the size and power consumption is of prime importance. Digital modulator is the most important part of Sigma Delta DACs. This paper presents a new approach for the implementation of a sample digital MASH 1-1 and MOD 2 modulator using Gate Diffusion Input (GDI) technique. The same modulators are also implemented in standard CMOS technology and are compared for the tone frequencies of the audio frequency range. The proposed modulators using GDI method provide a significant improvement in the area, power, and power delay product as compared to CMOS. The gate level simulation using WinSpice with 0.18 µm technology confirms the usefulness of the presented structures. Keywords: Area, CMOS, GDI, MASH 1-1, MOD 2, Power