Electronically tunable voltage-mode universal filter using simple OTAs

Abstract

This paper presents a new voltage-mode universal filter with single-input multiple-output employing seven simple CMOS operational transconductance amplifiers, two grounded capacitors and one resistor. The proposed filter can realize lowpass, bandpass, highpass, bandstop and allpass voltage responses from the same topology. The natural frequency (Z o ) and the quality factor (Q) can be controlled orthogonally and electronically by adjusting the bias currents of OTAs. The performances of the proposed circuit are simulated with PSPICE to confirm the presented theory.

Electronically Tunable Triple-Input Single-Output Voltage-Mode Biquadratic Filter Implemented with Single Integrated Circuit Package

“…Nowadays, the realization of an active analog filter using versatile active building blocks has been focused by many researchers due to many advantage features, such as simple circuitry, high linearity, and wide dynamic range. In the literature, many modern active electronic elements have been utilized in analog active filter design, such as current conveyor (CC) [1][2][3][4][5][6][7], differential difference current conveyor (DDCC) [8][9][10][11][12], differential voltage current conveyor (DVCC) [13][14][15][16], fully differential second-generation current conveyor (FDCCII) [17], current differencing buffered amplifier (CDBA) [18][19][20], current feedback operational amplifier (CFOA) [21][22][23][24][25][26][27], current follower transconductance amplifier (CFTA) [28][29], operational transconductance amplifier (OTA) [30][31][32][33][34], voltage differencing buffered amplifier (VDBA) [35][36], voltage differencing inverting buffered amplifier (VDIBA) [37], fully balanced voltage differencing buffered amplifier (FB-VDBA) [38], voltage differencing transconductance amplifier (VDTA) [39][40][41], and voltage diffe...…”