Title :
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
fDate :
12/1/1995 12:00:00 AM
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 Vpp/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;
Journal_Title :
Solid-State Circuits, IEEE Journal of
