A positive-feedback transconductance amplifier with applications to high-frequency, high-Q CMOS switched-capacitor filters

Author

Laber, Carlos A. ; Gray, Paul R.

Author_Institution

Micro Linear Corp., San Jose, CA, USA

Volume

23

Issue

6

fYear

1988

fDate

12/1/1988 12:00:00 AM

Firstpage

1370

Lastpage

1378

Abstract

The authors describe a high-bandwidth amplifier that simultaneously achieves high gain by using internal positive feedback. The results obtained when the amplifier is used in a general-purpose switched-capacitor biquadratic building block are also presented. This device achieves 150-kHz center-frequency operation with Q accuracy of 15% when clocked at 7.5 MHz with 10-V ±10% supplies from -55°C to +125°C. With a minimum power supply of 4.5 V, this filter operates with center frequencies up to 100 kHz when clocked at 5 MHz, while performing with the same accuracy and across the same temperature range as above

Keywords

CMOS integrated circuits; feedback; operational amplifiers; switched capacitor filters; -55 to 125 degC; 100 kHz; 150 kHz; 5 MHz; 7.5 MHz; high-Q CMOS switched-capacitor filters; high-bandwidth amplifier; positive-feedback transconductance amplifier; switched-capacitor biquadratic building block; CMOS analog integrated circuits; Capacitors; Clocks; Frequency; Operational amplifiers; Q factor; Resonator filters; Signal processing; Switching converters; Transconductance;

fLanguage

English

Journal_Title

Solid-State Circuits, IEEE Journal of

Publisher

ieee

ISSN

0018-9200

Type

jour

DOI

10.1109/4.90033

Filename

90033