Improving the bandwidth gain-independence and accuracy of the current feedback amplifier

Author

Gift, Stephan J G ; Maundy, Brent

Author_Institution

Dept. of Electr. & Comput. Eng., Univ. of the West Indies, St. Augustine, Trinidad and Tobago

Volume

52

Issue

3

fYear

2005

fDate

3/1/2005 12:00:00 AM

Firstpage

136

Lastpage

139

Abstract

A high-performance current feedback amplifier circuit referred to as an operational current feedback amplifier is described in this paper. The technique employed involves the incorporation of the input circuit of the current feedback amplifier in the feedback loop of an operational amplifier to reduce the input impedance at the inverting terminal of the current feedback amplifier. The new circuit possesses the gain accuracy and bandwidth of the current feedback amplifier but realizes significant improvement in bandwidth accuracy and bandwidth gain-independence. Experimentally, using AD844s, an order of magnitude reduction in bandwidth variation with changing gain was achieved in the noninverting configuration and almost complete bandwidth invariance was realized in the inverting configuration.

Keywords

circuit feedback; high-speed integrated circuits; operational amplifiers; AD844; analog processing circuits; bandwidth accuracy; bandwidth gain-independence; bandwidth invariance; feedback loop; gain accuracy; high-speed integrated circuits; input impedance; noninverting configuration; operational amplifier; operational current feedback amplifier; Bandwidth; Electronic circuits; Feedback amplifiers; Feedback circuits; Feedback loop; Helium; High speed integrated circuits; Impedance; Operational amplifiers; Transfer functions; Analog processing circuits; current feedback amplifier; high-speed integrated circuits; operational amplifier;

fLanguage

English

Journal_Title

Circuits and Systems II: Express Briefs, IEEE Transactions on

Publisher

ieee

ISSN

1549-7747

Type

jour

DOI

10.1109/TCSII.2004.842043

Filename

1406203