Super Class-AB OTAs With Adaptive Biasing and Dynamic Output Current Scaling

Author

Galan, Juan A. ; López-Martín, Antonio J. ; Carvajal, Ramón G. ; Ramírez-Angulo, Jaime ; Rubia-Marcos, Carlos

Author_Institution

Dept. of Electron. Eng., Univ. of Huelva

Volume

54

Issue

3

fYear

2007

fDate

3/1/2007 12:00:00 AM

Firstpage

449

Lastpage

457

Abstract

A new family of single-stage super Class-AB operational transconductance amplifiers (OTAs) suitable for low-voltage operation and low power consumption is presented. Three novel topologies are proposed featuring simplicity and compactness. They are based on the combination of adaptive biasing techniques for the differential input stage and nonlinear current mirrors for the active load that provide additional dynamic current boosting. The OTAs have been fabricated in a standard 0.5-mum CMOS process. Experimental results show a greatly improved slew rate by factors 30-60 and gain-bandwidth product by factors 11.5-17 when compared to a classical Class-A OTA. The circuits are operated at plusmn1-V supply voltage with only 10 muA of bias current

Keywords

CMOS analogue integrated circuits; current mirrors; low-power electronics; operational amplifiers; 0.5 micron; 10 muA; CMOS process; adaptive biasing techniques; class-AB OTA; class-AB operational transconductance amplifiers; differential input stage; dynamic current boosting; dynamic output current scaling; nonlinear current mirrors; Boosting; CMOS analog integrated circuits; CMOS process; Circuit topology; Design optimization; Energy consumption; Mirrors; Operational amplifiers; Transconductance; Voltage; Adaptive biasing; CMOS amplifiers; Class-AB amplifiers; analog CMOS circuits; low-power and low-voltage CMOS circuits; operational transconductance amplifier (OTA);

fLanguage

English

Journal_Title

Circuits and Systems I: Regular Papers, IEEE Transactions on

Publisher

ieee

ISSN

1549-8328

Type

jour

DOI

10.1109/TCSI.2006.887639

Filename

4126793