Title :
Improved dynamic range, digitally-controlled linear-in-dB CMOS variable gain amplifier
Author :
Purighalla, Sandhya ; Maundy, Brent
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Calgary, Calgary, AB, Canada
Abstract :
A new digitally-controlled exponential variable gain amplifier is presented in this paper. This circuit is based on the proposed novel method of expanding the dynamic range over which a traditional approximate function estimates the ideal exponential function. The technique is unique in a way that it culminates in a true exponential amplifier over an improved input dynamic range. Tuning in this circuit has been achieved using a single digitally switched variable resistor. Finally, the circuit has been implemented in a TSMC 0.18 μm CMOS technology and displays a gain from about - 21 dB to 36 dB in steps of 3.89 dB with a linear error in [-0.66 dB, 0.45 dB].
Keywords :
CMOS integrated circuits; amplifiers; resistors; TSMC CMOS technology; digitally switched variable resistor; digitally-controlled exponential variable gain amplifier; dynamic range expansion; ideal exponential function; size 0.18 mum; traditional approximate function; Approximation methods; CMOS integrated circuits; Dynamic range; Gain; Gain control; Resistors; Simulation; Pseudo-exponential amplifier; digitally-controlled variable resistor; dynamic range expansion; non-linear D/A converter; variable gain amplifier;
Conference_Titel :
Circuits and Systems (ISCAS), 2011 IEEE International Symposium on
Conference_Location :
Rio de Janeiro
Print_ISBN :
978-1-4244-9473-6
Electronic_ISBN :
0271-4302
DOI :
10.1109/ISCAS.2011.5938116
