Universal filter and its oscillator modification employing only active components

An active-only devices current-mode universal filter using the biquadratic transfer function is proposed. The proposed circuit is realized based on minimized active-only components count without external passive elements. The electronic resistors are used instead of 2 OTAs. The different kinds of filter function such as lowpass, highpass, bandpass and band-reject response can be obtained without changing circuit topology. A quadrature oscillator can also be easily modified without changing circuit topology. The proposed circuit is realized by using 4 MOS transistors, 3 OTAs, and 2 Opamps. The parameters ωP and QP can be electronically tuned independently through adjusting the transconductance gains of the OTAs. The simulation results are given by PSpice.

[1]  A. C. van der Woerd,et al.  Current-mode companding /spl radic/x-domain integrator , 1996 .

[2]  Montree Siripruchyanun,et al.  CMOS current-controlled current differencing transconductance amplifier and applications to analog signal processing , 2008 .

[3]  E. O. Gunes,et al.  Insensitive current-mode universal filter with minimum components using dual-output current conveyors , 1999 .

[4]  Serdar Ozoguz,et al.  A new versatile building block: current differencing buffered amplifier suitable for analog signal-processing filters , 1999 .

[5]  Yasuaki Sumi,et al.  Novel voltage-mode biquad using only active devices , 2001 .

[6]  Kobchai Dejhan,et al.  An integrable electronic-controlled quadrature sinusoidal oscillator using CMOS operational transconductance amplifier , 2002 .

[7]  Shen-Iuan Liu,et al.  New current mode biquad filters using current followers , 1995 .

[8]  Yutaka Fukui,et al.  Current-mode biquad without external passive elements , 1996 .

[9]  Muhammad Taher Abuelma'atti,et al.  Universal three input and one output current-mode filter without external passive elements , 1997 .

[10]  Yasuaki Sumi,et al.  Voltage-mode active-only biquad , 2000 .

[11]  Chun-Ming Chang,et al.  New multifunction OTA-C biquads , 1999 .

[12]  L. P. Huelsman,et al.  State-Variable Synthesis for Insensitive Integrated Circuit Transfer Functions , 1967 .

[13]  Ali Toker,et al.  Insensitive current-mode universal filter using dual output current conveyors , 2000 .

[14]  Yasuaki Sumi,et al.  Electronically tunable current-mode active-only biquadratic filter , 2000 .