Fully-differential CMOS current-mode amplifiers and filters

Author

Zele, Rajesh H. ; Allstot, David J. ; Fiez, Terri S.

Author_Institution

Dept. of Electr. & Comput. Eng., Carnegie Mellon Univ., Pittsburgh, PA, USA

fYear

1991

fDate

16-17 Jun 1991

Firstpage

781

Abstract

A CMOS fully-differential current-mode analog signal processing technique has been developed. The basic building block, a 5-volt fully-differential current-mode operational amplifier (I-OPAMP), has been integrated using the MOSIS 2 μm n-well CMOS technology. Measured total harmonic distortion (THD) is -70 dB with a peak signal (iˆ) to bias current (I) ratio of 0.5. By simply adding MOS switches, the I-OPAMP topology is easily extended to implement fully-differential switched-current (SI) circuits with first-order cancellation of clock-feedthrough effects. A five-pole Chebyshev lowpass fully-differential SI ladder filter has also been integrated in a 2 μm p-well CMOS technology. Measured results show that with a sampling frequency of 128 kHz, the desired ripple bandwidth of 5 kHz is accurately realized using the fully-differential SI structure. Dynamic range is greater than 80 dB with a power dissipation of 14 mW

Keywords

CMOS integrated circuits; active filters; differential amplifiers; ladder networks; linear integrated circuits; low-pass filters; operational amplifiers; switched capacitor filters; 128 kHz; 14 mW; 2 micron; 5 V; 5 kHz; CMOS; MOS switches; MOSIS; THD; analog signal processing; clock-feedthrough effects; current-mode amplifiers; filters; first-order cancellation; five-pole Chebyshev filter; fully-differential SI structure; ladder filter; lowpass filter; n-well CMOS technology; operational amplifier; p-well CMOS technology; power dissipation; switched-current; total harmonic distortion; CMOS process; CMOS technology; Current measurement; Distortion measurement; Filters; Integrated circuit measurements; Integrated circuit technology; Operational amplifiers; Signal processing; Switching circuits;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems, 1991. Conference Proceedings, China., 1991 International Conference on

Conference_Location

Shenzhen

Type

conf

DOI

10.1109/CICCAS.1991.184477

Filename

184477