Title :
Fully-differential CMOS current-mode circuits
Author :
Zele, Rajesh H. ; Allstot, David J. ; Fiez, Terri S.
Author_Institution :
Dept. of Electr. & Comput. Eng., Carnegie Mellon Univ., Pittsburgh, PA, USA
Abstract :
A CMOS fully-differential current-mode analog signal processing technique has been developed. The basic building block, a 5-V 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 to bias current 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 the 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; 128 kHz; 14 mW; 2 micron; 5 V; 5 kHz; MOS switches; analog signal processing; clock-feedthrough effects; current-mode circuits; first-order cancellation; five-pole Chebyshev lowpass; ladder filter; n-well CMOS technology; operational amplifier; p-well CMOS technology; power dissipation; switched-current circuits; CMOS process; CMOS technology; Current mode circuits; Differential amplifiers; Distortion measurement; Integrated circuit measurements; Integrated circuit technology; Operational amplifiers; Signal processing; Switching circuits;
Conference_Titel :
Custom Integrated Circuits Conference, 1991., Proceedings of the IEEE 1991
Conference_Location :
San Diego, CA
Print_ISBN :
0-7803-0015-7
DOI :
10.1109/CICC.1991.164055
