A low voltage, rail-to-rail, class AB CMOS amplifier with high drive and low output impedance characteristics

Author

Rincon-Mora, Gabriel A. ; Stair, Richard

Author_Institution

Sch. of Electr. & Comput. Eng., Georgia Inst. of Technol., Atlanta, GA, USA

Volume

48

Issue

8

fYear

2001

fDate

8/1/2001 12:00:00 AM

Firstpage

753

Lastpage

761

Abstract

This paper describes a CMOS rail-to-rail class AB operational amplifier designed to have extremely low output impedance and large current-drive capability. The amplifier uses an innovative output stage, having both source follower and common source stages working simultaneously throughout the output common-mode range. The source follower ensures low output impedance, which enables it to drive relatively large load capacitors, while the common-source gain stage provides high current drive. Furthermore, the circuit is fully functional with supplies as low as 1.5 V. The amplifier is capable of driving a maximum output current of ±7 mA with only 140 μA of total quiescent current, making it power efficient, and thus appropriate for low voltage battery-powered applications

Keywords

CMOS analogue integrated circuits; compensation; electric impedance; feedback amplifiers; low-power electronics; operational amplifiers; -7 mA; 1.5 V; 140 muA; 7 mA; CMOS operational amplifier; LV battery-powered applications; class AB op amp; common mode feedback; common source stage; high drive characteristics; low output impedance characteristics; output stage; rail-to-rail opamp; source follower stage; Capacitors; Circuit topology; Driver circuits; Energy consumption; Impedance; Low voltage; Operational amplifiers; Rail to rail amplifiers; Rail to rail operation; Rail to rail outputs;

fLanguage

English

Journal_Title

Circuits and Systems II: Analog and Digital Signal Processing, IEEE Transactions on

Publisher

ieee

ISSN

1057-7130

Type

jour

DOI

10.1109/82.959865

Filename

959865