A CMOS Chopper Offset-Stabilized Opamp

Author

Witte, Johan F. ; Makinwa, Kofi A A ; Huijsing, Johan H.

Author_Institution

Delft Univ. of Technol., Delft

Volume

42

Issue

7

fYear

2007

fDate

7/1/2007 12:00:00 AM

Firstpage

1529

Lastpage

1535

Abstract

In this paper, an offset-stabilized operational amplifier is described. The amplifier employs a chopper amplifier in a low frequency path to cancel the offset of a wide-bandwidth amplifier. A sample-and-hold circuit is used to reduce the chopper ripple, and the low frequency path is also offset-stabilized to further reduce the residual offset. The amplifier has less than 1.5 offset at a 16-kHz chopper frequency, a unity gain frequency of 1.3 MHz with a 50-pF load, and draws 700 from a 5-V supply. The amplifier was realized in a 0.7 CMOS process, and has an effective chip area of 3.6.

Keywords

CMOS analogue integrated circuits; choppers (circuits); operational amplifiers; sample and hold circuits; CMOS chopper; chopper amplifier; effective chip area; offset-stabilized opamp; operational amplifier; sample-and-hold circuit; Bandwidth; Broadband amplifiers; CMOS process; Choppers; Circuits; Frequency; Low-frequency noise; Noise cancellation; Noise reduction; Operational amplifiers; CMOS analog integrated circuits; Choppers; low-offset; operational amplifiers;

fLanguage

English

Journal_Title

Solid-State Circuits, IEEE Journal of

Publisher

ieee

ISSN

0018-9200

Type

jour

DOI

10.1109/JSSC.2007.899080

Filename

4261021