Design and Verification of a Switchable Opamp for Switched-Capacitor Integrators

Author

Haroun, Mostafa A. N. ; Hamoui, Anas A.

Author_Institution

Dept. of Electr. & Comput. Eng., McGill Univ., Montreal, QC, Canada

Volume

61

Issue

10

fYear

2014

fDate

Oct. 2014

Firstpage

738

Lastpage

742

Abstract

A switchable operational amplifier (opamp) is examined in this brief. It is based on a current-mirror opamp with switchable transconductance values. Contrary to switched opamp (SO) and partial SO, it can be used to realize both half-delay and full-delay switched-capacitor integrators. The added circuit design complexity is shown to be minimal. Optimal switching is developed in this brief. It is also shown in this brief that the absolute average power consumption can be less as compared with an SO design. The experimental results of a delta-sigma modulator prototype (designed in 1-V 65-nm CMOS), employing the designated switchable-opamp technique, show power reduction without any degradation in SNDR (58.5 dB) or SFDR (67 dB).

Keywords

CMOS integrated circuits; current mirrors; delta-sigma modulation; integrated circuit design; integrating circuits; low-power electronics; operational amplifiers; switched capacitor networks; CMOS integrated circuit; average power consumption; current mirror operational amplifier; delta-sigma modulator; optimal switching; switchable operational amplifier; switchable transconductance value; switched capacitor integrators; voltage 1 V; wavelength 65 nm; Capacitors; Circuit synthesis; Modulation; Optimized production technology; Switches; Switching circuits; Transconductance; Circuits; delta??sigma ( $DeltaSigma$); operational amplifier (opamp); switchable opamp; switched capacitor (SC); switched opamp (SO); switching;

fLanguage

English

Journal_Title

Circuits and Systems II: Express Briefs, IEEE Transactions on

Publisher

ieee

ISSN

1549-7747

Type

jour

DOI

10.1109/TCSII.2014.2335419

Filename

6848788