Electronically tunable first-order all pass sections using OTAs

Design and practice of simple first-order all-pass filters using commercially available IC and their applications

“…The voltagemode firstorder allpass filters have been presented in the literature, using a variety of active building blocks. They are constructed with active elements such as current feedback ope rational ampli fiers (CFOAs) [1,13], current controlled conveyors (CCCII) [2,14,20], LT1228 [3], secondgenera-Engineering tion current conveyors (CCII) [4,8,26], differential voltage current conveyors (DVCC) [5,12,22], voltage differencing inverting buffered amplifier (VDIBA) [6], differential voltage current conveyor transconductance amplifier (DVCCTA) [7], fully differential second generation current conveyors (FDCCII) [9][10], operational transresistance amplifier (OTRA) [11], a fully balanced voltage differencing buffered amplifier (FBVDBA) [15], current controlled conveyor transconductance amplifier (CCCTA) [16], operational transconductance amplifiers (OTAs) [17,18,21], voltage differencing transconductance amplifier (VDTA) [19], current controlled thirdgeneration voltage conveyor (CCVCIII-) [23], controlled current conveyor transconductance ampli fier (MO-CCCCTA) [24], current-controlled current differencing buffered amplifier (CCCDBA) [25], Current controlled current conveyor transconductance amplifier (CCCCTA) [27], differential difference current conveyor transconductance amplifier (DDCCTA) [28], and current differencing buffer amplifier (CDBA) [29]. Most APF circuits can be adjusted for the pole frequency and phase response by electronic adjustment [4-6, 10-12, 25, 27, 28].…”

First Order Mixed Mode MOS-C All-Pass Frequency Selective Analog Network with Electronic Tuning

“…Various voltage mode (VM) APFs are documented in the existing literature [2][3][4][5]8,10,[12][13][14][15]17,19,20,[22][23][24][25]27,28]. Similarly, the varieties of current mode (CM) APFs [6,7,9,11,16,21,[29][30][31][32][33] are also reported. One trans-admittance mode (TAM) APF is presented in [18].…”

“…2) In comparison to realizations with more than 2 active elements, filter realizations based on 1 or 2 active elements offer simpler circuit designs. APFs circuits reported in [3,7,16,[19][20][21][22][23]25,30,33] have 3 or more than 3 active elements.…”

“…3) MOS-C filters realizations have the ability of tuning the pole frequency electronically. Filters reported in [3,[7][8][9][10][13][14][15][16]18,19,[21][22][23]27,30,33] have electronically tunable structure.…”

CMOS Realization of VDVTA and OTA Based Fully Electronically Tunable First Order All Pass Filter with Optimum Linearity at Low Supply Voltage ± 0.85 V

“…Recently, most widely active building blocks are used in the designing oscillators, grounded Inductor and active filter applications. These active building blocks namely operational Amplifier, Current-mode current, gain first-order all pass filters employing CFTAs [1], A voltage-mode first order all pass filter based on VDTA [2], Voltage-mode all-pass filters including minimum component count circuits [3], Voltage-mode cascadable all-pass section using single active element [4], Single VDVTA Based Voltage-Mode Biquad Filter [5], Single MO-CCCCTA-Based Electronically Tunable Current/Trans-Impedance-Mode Biquad Universal Filter [6], Electronically Tunable Low Voltage Mixed-Mode Universal Biquad Filter [7], Current-tunable current-mode all-pass section using DDCC [8], Electronically tunable first-order all pass section using OTAs [9], Current-mode multi phase sinusoidal oscillator using CDTA-based all pass sections [10], New resistorless and electronically tunable realization of dual-output VM all-pass filter using VDIBA [11], Cascadable Current-mode first order all-pass filter based on minimal components [12], Voltage-mode all-pass filters using universal voltage conveyor and MOSFET-based electronic Resistors [13], Voltage mode cascadable all-pass sections using single active element and grounded passive components [14], Electronically tunable first-order all-pass circuit employing DVCC [15], Novel voltage-mode all-pass filter based on using DVCCs [16], A Resistorless realization of the first-order all-pass filter [17], High input impedance voltage-mode first-order all-pass sections [18], Unity/variable-gain voltage-mode/current-mode first-order all-pass filters using single DXCCII [19], First-order voltage-mode all-pass filter employing one active element and one grounded capacitor [20], Component reduced all-pass filter with a grounded capacitor and high-impedance input [21], Realization of Grounded Inductor Based Band Pass Filter Design to Achieve Optimum Linearity with Bandwidth using Single VDVTA [22], Multi output filter and four phase sinusoidal oscillator using CMOS DX-MOCCII [23], FDCCII based Electronically Tunable Voltage Mode Biquad Filter [24], CDBA Based Inverse Filter [25].…”