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

Volume

39

Issue

7

fYear

2004

fDate

7/1/2004 12:00:00 AM

Firstpage

1213

Lastpage

1216

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;

fLanguage

English

Journal_Title

Solid-State Circuits, IEEE Journal of

Publisher

ieee

ISSN

0018-9200

Type

jour

DOI

10.1109/JSSC.2004.829919

Filename

1308600