A 1.5 V class AB CMOS buffer amplifier for driving low-resistance loads

Author

Van Dongen, Rob ; Rikkink, Vincent

Author_Institution

Centre Suisse d´´Electronique et de Microtechnique SA, Neuchatel, Switzerland

Volume

30

Issue

12

fYear

1995

fDate

12/1/1995 12:00:00 AM

Firstpage

1333

Lastpage

1338

Abstract

A 1.5 V class AB CMOS op amp that can drive heavy resistive loads with low distortion is presented. Its output stage comprises an elementary shunt stage driven by a transconductor block. Only seven transistors are needed to implement the complete output stage, including the class AB current control. The gain of the output stage remains relatively constant for varying load conditions, which makes it possible to use a simple two-stage architecture for the overall amplifier. At 1.5 V, the circuit dissipates 135 μW of quiescent power, has a gain-bandwidth of 0.85 MHz and can drive a 1.0 V_pp/1 kHz sine wave in a 560 Ω load with a THD of 0.2%

Keywords

CMOS analogue integrated circuits; buffer circuits; operational amplifiers; 0.85 MHz; 1.5 V; 135 muW; 560 ohm; CMOS buffer amplifier; CMOS opamp; class AB; heavy resistive load driving; low distortion; low-resistance loads; shunt stage; transconductor block; two-stage architecture; Auditory system; Current control; Diodes; Drives; Energy consumption; Feedback circuits; Headphones; Low voltage; Rail to rail outputs; Transconductors;

fLanguage

English

Journal_Title

Solid-State Circuits, IEEE Journal of

Publisher

ieee

ISSN

0018-9200

Type

jour

DOI

10.1109/4.482159

Filename

482159