A high-swing CMOS telescopic operational amplifier

Author

Gulati, Kush ; Lee, Hae-Seung

Author_Institution

Dept. of Electr. Eng. & Comput. Sci., MIT, Cambridge, MA, USA

Volume

33

Issue

12

fYear

1998

fDate

12/1/1998 12:00:00 AM

Firstpage

2010

Lastpage

2019

Abstract

A high-swing, high-performance CMOS telescopic operational amplifier is described. The high swing of the op-amp is achieved by employing the tail and current source transistors in the deep linear region. The resulting degradation in differential gain, common-mode rejection ratio (CMRR), and other amplifier characteristics are compensated by applying regulated-cascode differential gain enhancement and a replica-tail feedback technique. A prototype of the op-amp has been built in a 0.81-μm CMOS process. Operating from a power supply of 3.3 V, it achieves a differential swing of ±2.15 V, a differential gain of 90 dB, unity-gain frequency of 90 MHz, and >50-dB CMRR. It is shown, analytically and through simulations, that the operational amplifier maintains its high CMRR even at high frequencies

Keywords

CMOS analogue integrated circuits; feedback amplifiers; operational amplifiers; 0.8 micron; 3.3 V; 90 dB; CMOS telescopic operational amplifier; common mode rejection ratio; differential swing; regulated cascode differential gain enhancement; replica tail feedback; unity gain frequency; CMOS process; Degradation; Differential amplifiers; Feedback; Frequency; Gain; Operational amplifiers; Power supplies; Prototypes; Tail;

fLanguage

English

Journal_Title

Solid-State Circuits, IEEE Journal of

Publisher

ieee

ISSN

0018-9200

Type

jour

DOI

10.1109/4.735542

Filename

735542