Modeling and Low-power Design of Continuous-time Sigma-Delta Modulator
LU Congyuan
BU Gang
Abstract：By overcoming the speed limitation of discrete-time Sigma-Delta modulators,continuous-time Sigma-Delta modu-lators have received widespread attention in the field of broadband communications.Furthermore,the continuous-time Sigma-Delta modulators provide possible solutions to low-power design of narrow-to-moderate bandwidth high resolution ADCs.In this paper,through Simulink modeling and analysis of the non-ideal factors of the composing modules of a third-order continuous-time Sig-ma-Delta,the lowest specifications of the modules to meet the accuracy requirements are derived.Then,based on 0.18 μm CMOS SMIC process and under the 1.8 V power supply voltage,the transistor level circuit of the modulator is designed.The results show that with 1 MHz bandwidth,the in-band signal-to-noise ratio of the modulator output signal is 76.2 dB,and the total power con-sumption is 3 mW.
Keywords：CT Sigma-Delta modulatorSimulink modeling analysislow-power design
Publication Date：2025-04-20
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 91-96 )