Title :
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
fDate :
8/1/2001 12:00:00 AM
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;
Journal_Title :
Circuits and Systems II: Analog and Digital Signal Processing, IEEE Transactions on
