Analysis of a composite amplifier technique for optimum noise performance

Author

Peyton, A.J. ; Abou-Fakher, Y. ; Wilson, B.

Author_Institution

Dept. of Electr. Eng. & Electron., Univ. of Manchester Inst. of Sci. & Technol., UK

Volume

141

Issue

3

fYear

1994

fDate

6/1/1994 12:00:00 AM

Firstpage

210

Lastpage

214

Abstract

A technique for combining two voltage-operational amplifiers to create a single composite-voltage operational amplifier (VOA) is analysed. The composite amplifier can be treated essentially as a single VOA which gives an optimum combination of the DC and AC performances of the two constituent amplifiers. Specific practical examples of the technique have been previously reported, but in this paper we present an analysis and establish the optimum combination conditions. To support the analysis a further example of the composite technique is presented in which a high-performance chopper-stabilised VOA (MAX 430) is coupled with a low-noise bipolar VOA (OP 27). Measurements have shown that the composite device exhibits premium qualities from both OA, with low noise and very low input-offset voltage drift

Keywords

feedback; frequency response; linear network analysis; noise; operational amplifiers; MAX 430; OP 27; chopper-stabilised type; composite amplifier technique; composite-voltage opamp; low-noise bipolar type; optimum combination conditions; optimum noise performance; voltage-operational amplifiers;

fLanguage

English

Journal_Title

Circuits, Devices and Systems, IEE Proceedings -

Publisher

iet

ISSN

1350-2409

Type

jour

DOI

10.1049/ip-cds:19941023

Filename

296527