Title :
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
fDate :
9/1/2002 12:00:00 AM
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;
Journal_Title :
Circuits and Systems I: Fundamental Theory and Applications, IEEE Transactions on
DOI :
10.1109/TCSI.2002.802365
