Variable gain amplifiers based on a new approximation method to realize the exponential function

Author

Abdelfattah, Khaled M. ; Soliman, Ahmed M.

Author_Institution

Dept. of Electr. Eng., California Univ., Los Angeles, CA, USA

Volume

49

Issue

9

fYear

2002

fDate

9/1/2002 12:00:00 AM

Firstpage

1348

Lastpage

1354

Abstract

A new current mode variable-gain amplifier (VGA) is developed. The new circuit is based on a novel approximation function that is very close to the ideal exponential relation over a very wide range. Pspice simulations are provided based on Mietec 0.5-μm CMOS technology. The simulations show that the dynamic range achieved is over 50 dB in a single stage. The proposed circuit consumes average power less than 1.2 mW using ±1.5 V supply voltages.

Keywords

CMOS analogue integrated circuits; automatic gain control; current-mode circuits; feedback amplifiers; functions; -1.5 V; 0.5 micron; 1.2 mW; 1.5 V; AGC loop; Mietec CMOS technology; Pspice simulations; approximation function; automatic gain control loop; current mode amplifier; dynamic range; feedback system; variable-gain amplifier; Approximation methods; Auditory system; Bipolar transistors; CMOS technology; Circuit simulation; Communication system control; Difference equations; Dynamic range; Gain control; Voltage;

fLanguage

English

Journal_Title

Circuits and Systems I: Fundamental Theory and Applications, IEEE Transactions on

Publisher

ieee

ISSN

1057-7122

Type

jour

DOI

10.1109/TCSI.2002.802365

Filename

1031970