Title :
A CMOS Chopper Offset-Stabilized Opamp
Author :
Witte, Johan F. ; Makinwa, Kofi A A ; Huijsing, Johan H.
Author_Institution :
Delft Univ. of Technol., Delft
fDate :
7/1/2007 12:00:00 AM
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;
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.2007.899080
