A 3.86mW 106.4dB SNDR Delta-Sigma modulator based on Switched-Opamp for audio codec

Author

Zhongyi Huang ; Menglian Zhao ; Xiaolin Yang ; Liyu Lin ; Xiaobo Wu

Author_Institution

Inst. of VLSI design, Zhejiang Univ., Hangzhou, China

fYear

2014

fDate

3-6 Aug. 2014

Firstpage

761

Lastpage

764

Abstract

A low-power high-resolution Delta-Sigma modulator for audio codec, designed in Global-Foundries BCD 0.18μm 1P4M CMOS process, is presented. The modulator employs a fourth-order single-loop feedforward topology with a 3bit-quantizer. A novel structure of Switched-Opamp (SO) utilizing current-starvation and Slew-Rate (SR) boosting is adopted to meet the requirements of high performance and fast settling time. The opamp-shared technique and two-step summation are used to reduce power dissipation further. Meanwhile, to improve the resolution, chopper-stabilization (CHS) and pseudo data-weighted-averaging (PDWA) circuits are employed in this paper. The proposed modulator achieves 3.86mW power consumption and 106.4dB Signal-to-Noise Distortion Ratio (SNDR) with a FOM value of 0.56pJ/conv.-step at a supply voltage of 3.3V and a high working frequency of 6.25MHz, which is suitable for audio applications.

Keywords

CMOS analogue integrated circuits; audio coding; audio-frequency amplifiers; choppers (circuits); codecs; delta-sigma modulation; low-power electronics; operational amplifiers; CHS; FOM; Global-Foundries BCD 1P4M CMOS process; PDWA; SNDR delta-sigma modulator; SO; SR; audio codec; current-starvation; fourth-order single-loop feedforward topology; low-power high-resolution delta-sigma modulator; opamp-shared technique; power 3.86 mW; power dissipation reduction; pseudo data-weighted-averaging circuits; quantizer; resolution chopper-stabilization; signal-to-noise distortion ratio; size 0.18 mum; slew-rate boosting; switched-opamp; two-step summation; voltage 3.3 V; word length 3 bit; Adders; Boosting; Modulation; Power demand; Simulation; Switches; Topology; CHS; Delta-Sigma Modulator; Opamp-shared; PDWA; SO;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems (MWSCAS), 2014 IEEE 57th International Midwest Symposium on

Conference_Location

College Station, TX

ISSN

1548-3746

Print_ISBN

978-1-4799-4134-6

Type

conf

DOI

10.1109/MWSCAS.2014.6908526

Filename

6908526