An automatic offset compensation scheme with ping-pong control for CMOS operational amplifiers

Author

Yu, Chong-Gun ; Geiger, Randall L.

Author_Institution

Dept. of Electr. Eng. & Comput. Eng., Iowa State Univ., Ames, IA, USA

Volume

29

Issue

5

fYear

1994

fDate

5/1/1994 12:00:00 AM

Firstpage

601

Lastpage

610

Abstract

An automatic offset compensation scheme for CMOS operational amplifiers is presented. Offset is reduced by digitally adjusting the bias voltage of a programmable current mirror which is used as the load of the differential input stage. A 100% operating duty cycle is obtained by using a ping-pong structure. The offset compensation scheme is inherently time and temperature stable since the offset compensation is periodically performed with the ping-pong control. The proposed circuit has been fabricated using a 1.0 μm n-well CMOS process. The measured offset voltages of the test circuits are less than 400 μV in magnitude

Keywords

CMOS integrated circuits; differential amplifiers; digital control; error compensation; linear integrated circuits; operational amplifiers; tuning; 1 micron; 100% operating duty cycle; CMOS operational amplifiers; automatic offset compensation scheme; bias voltage; differential input stage; digital adjustment; n-well CMOS process; op amp; ping-pong control; programmable current mirror; Automatic control; CMOS process; Circuit testing; Mirrors; Operational amplifiers; Resistors; Switches; Temperature control; Variable structure systems; Voltage;

fLanguage

English

Journal_Title

Solid-State Circuits, IEEE Journal of

Publisher

ieee

ISSN

0018-9200

Type

jour

DOI

10.1109/4.284713

Filename

284713