Title :
A high-swing 2 V CMOS operational amplifier with gain enhancement using a replica amplifier
Author :
Yu, P.C. ; Lee, H.-S.
Author_Institution :
MIT, Cambridge, MA, USA
Abstract :
An open-loop gain enhancement circuit in 1.2- mu m CMOS that does not require cascode or long-channel transistors, thus maximizing output swing and input common-mode range, is described. Since gain enhancement is not achieved by increasing output resistance, but by matching main and replica amplifiers, high effective open-loop gain is maintained even with resistive loads. This circuit can be used with any transconductance amplifier circuit. A basic two-stage amplifier circuit demonstrates gain enhancement for low-voltage applications. The effective DC gain is increased by a factor of approximately 18 with no load resistor, and by a factor of 58 with a 1-k Omega load.<>
Keywords :
CMOS integrated circuits; linear integrated circuits; operational amplifiers; 1 kohm; 2 V; CMOS operational amplifier; effective DC gain; gain enhancement; input common-mode range; open-loop gain; output swing; replica amplifier; resistive loads; transconductance amplifier circuit; CMOS technology; Capacitors; Contracts; Coupling circuits; Equations; Feedback circuits; Operational amplifiers; Output feedback; Transconductance; Voltage;
Conference_Titel :
Solid-State Circuits Conference, 1993. Digest of Technical Papers. 40th ISSCC., 1993 IEEE International
Conference_Location :
San Francisco, CA, USA
Print_ISBN :
0-7803-0987-1
DOI :
10.1109/ISSCC.1993.280060
