An adjustable bandwidth analog CMOS Gm-C filter

Author

Ramezani, Lida

Author_Institution

Islamic Azad Univ., Tehran, Iran

Volume

2

fYear

2003

fDate

14-17 Dec. 2003

Firstpage

420

Abstract

A fifth order elliptic lowpass Gm-C filter with adjustable bandwidth is presented. This filter consists of cascaded Gm-C integrator and biquadratic sections. We used simple fully differential source degenerated operational transconductance amplifier with folded cascode output stage and common mode feedback circuit for Gin and substrate biased depletion mode MOS gate capacitors. The transconductor gain is constant and the capacitor is variable, so frequency tuning is done using bulk voltage of MOS gate capacitors. The filter has ±2.5V supply voltage and its power consumption is about 34mW for all tuned frequencies. HSPICE simulation results using 0.35μm CMOS process model parameters are given and advantages of this tuning method in comparison with other existing methods are presented.

Keywords

CMOS analogue integrated circuits; SPICE; circuit tuning; continuous time filters; elliptic filters; feedback amplifiers; low-pass filters; operational amplifiers; 2.5 V; 34 mW; Gm-C integrator sections; HSPICE simulation; adjustable bandwidth filters; analog CMOS Gm-C filter; antialiasing filters; biquadratic sections; cascaded sections; common mode feedback circuit; continuous-time filters; differential source degenerated OTA; fifth order elliptic filter; folded cascode output stage; lowpass filter; model parameters; tuning method; Bandwidth; Differential amplifiers; Feedback circuits; Filters; Frequency; MOS capacitors; Operational amplifiers; Transconductance; Tuning; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Electronics, Circuits and Systems, 2003. ICECS 2003. Proceedings of the 2003 10th IEEE International Conference on

Print_ISBN

0-7803-8163-7

Type

conf

DOI

10.1109/ICECS.2003.1301811

Filename

1301811