Title :
Extending voltage-mode op amps to current-mode performance
Author :
Toumazou, C. ; Lidgey, F.J. ; Makris, C.A.
Author_Institution :
Dept. of Electr. Eng., Imperial Coll. of Sci., Technol. & Med., London, UK
fDate :
4/1/1990 12:00:00 AM
Abstract :
The authors review techniques for extending the output capabilities of conventional voltage-mode operational amplifiers to achieve current-mode performance. Tracing the development over the past two decades, a number of elegant and useful circuit topologies for realising amplifiers with controlled current output properties are described. In particular, the operational amplifier supply current sensing technique and its application to current follower and current conveyor circuit implementations is examined. The authors then view their work, based on enhancing the performance of conventional voltage-mode amplifier designs by application of these current-mode alternatives. A high performance follower based amplifier, a biquadratic filter section, a precision full-wave rectifier and an instrumentation amplifier based upon enhancement to the voltage operational amplifier are shown to outperform their conventional counterparts
Keywords :
CMOS integrated circuits; linear integrated circuits; network topology; operational amplifiers; CMOS IC; biquadratic filter section; circuit topologies; current conveyor; current feedback; current follower; current-mode performance; full-wave rectifier; instrumentation amplifier; output capabilities; push-pull output stage; voltage-mode op amps;
Journal_Title :
Circuits, Devices and Systems, IEE Proceedings G
