Design and optimization of MOSFET-capacitor filters using CMOS current conveyors

Author

Liu, Shen-Iuan ; Tsao, Hen-Wai ; Wu, Jingshown ; Yu, Tsai-Chung ; Lin, Tung-Kwan

Author_Institution

Dept. of Electr. Eng., Nat. Taiwan Univ., Taipei, Taiwan

fYear

1990

fDate

1-3 May 1990

Firstpage

2283

Abstract

A CMOS current conveyor is proposed, and an MOSFET-capacitor integrator consisting of the CMOS current conveyor, MOSFETs biased in the triode region, capacitors, and a unity-gain buffer is presented. Based on this integrator, high-frequency integrated filters can be constructed. However, the design of such filters is complicated by the fact that the effective mobility of each device may vary and the basic building blocks (i.e. operational amplifiers or CMOS current conveyors) are not ideal. An optimization program has been developed to automate the design of this kind of filter. The program iteratively adjusts the W/L ratios and capacitance values through interfacing with SPICE to achieve the desired filtering performance. Simulation results on a six-order bandpass ladder filter with center frequency at 460 kHz, 0.5-dB ripple in the passband, and a bandwidth of 120 kHz are presented

Keywords

CMOS integrated circuits; active filters; active networks; band-pass filters; circuit CAD; field effect transistor circuits; ladder networks; optimisation; CMOS current conveyors; MOSFET-capacitor filters; SPICE; bandpass ladder filter; high-frequency integrated filters; integrator; optimization program; triode region; unity-gain buffer; Band pass filters; Capacitance; Capacitors; Design optimization; Filtering; Frequency; MOSFETs; Operational amplifiers; Passband; SPICE;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems, 1990., IEEE International Symposium on

Conference_Location

New Orleans, LA

Type

conf

DOI

10.1109/ISCAS.1990.112464

Filename

112464