Title :
A low-power switched-capacitor variable gain amplifier
Author :
Fujimoto, Yoshihisa ; Tani, Hitoshi ; Maruyama, Masahiko ; Akada, Hiroyuki ; Ogawa, Hiroaki ; Miyamoto, Masayuki
Author_Institution :
Sharp Corp., Nara, Japan
fDate :
7/1/2004 12:00:00 AM
Abstract :
A novel power reduction technique is proposed for a switched-capacitor amplifier (SCA) with two-stage operational amplifier. This technique improves both the bandwidth and the slew rate of the SCA with only two additional switches, and therefore, the power consumption of the SCA is reduced. This power reduction technique is applied to a variable gain amplifier (VGA) which is implemented in an analog front-end of camera modules for cellular phones. This reduces 30% of the VGA power consumption compared to the conventional one. Fabricated in 0.25-μm CMOS process with 3.3-V transistors and MIM capacitors, the VGA occupies 0.49×0.49 mm2 and dissipates 18.7 mW at 18 MHz with a supply voltage of 3.1 V.
Keywords :
CMOS integrated circuits; MIM devices; cameras; capacitors; gain control; low-power electronics; mobile handsets; operational amplifiers; switched capacitor networks; transistors; 0.25 micron; 18 MHz; 18.7 mW; 3.1 V; 3.3 V; CMOS process; MIM capacitors; VGA power consumption; analog front-end; bandwidth improvement; camera modules; cellular phones; low-power switched-capacitor amplifier; operational amplifier; power reduction; slew rate improvement; switched-circuits; transistors; variable gain amplifiers; Bandwidth; CMOS process; Cameras; Cellular phones; Energy consumption; Gain; MIM capacitors; Operational amplifiers; Power amplifiers; Switches; Analog front-end; camera modules; switched- circuits; variable gain amplifiers;
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.2004.829919
