An electronically tunable voltage-mode universal filter using two current conveyors

This study aims to design an electronically tunable voltage-mode (VM) universal filter utilizing commercially available LT1228 integrated circuits (ICs) with three-input and single-output (TISO) configuration. With the procedure based on two integrator loop filtering structures, the proposed filter consists of two LT1228s, four resistors, and two grounded capacitors. It realizes five filter output responses: low-pass, all-pass, band-reject, band-pass, and high-pass functions. By selecting input voltage signals, each output responses can be achieved without changing the circuit architecture. The natural angular frequency can be controlled electronically. The input voltage nodes Vin1 and Vin3 possess high impedance. The output node has low impedance, so it can be cascaded to other circuits. The performance of the proposed filter is corroborated by PSpice simulation and hardware implementation which support the theoretical assumptions. The result shows that the range of total harmonic distortion (THD) is lower than 1%, and that the higher the temperature is, the lower the natural angular frequency is.

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Electronically tunable voltage-mode universal filter with two inputs four outputs employing single-ended OTAs and grounded capacitors

2011 IEEE Colloquium on Humanities, Science and Engineering ◽

10.1109/chuser.2011.6163767 ◽

2011 ◽

Author(s):

Montree Kumngern

Keyword(s):

Universal Filter ◽

Voltage Mode ◽

Electronically Tunable

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The voltage-mode first order universal filter using single voltage differencing differential input buffered amplifier with electronic controllability

International Journal of Electrical and Computer Engineering (IJECE) ◽

10.11591/ijece.v12i2.pp1308-1323 ◽

2022 ◽

Vol 12 (2) ◽

pp. 1308

Author(s):

Danupat Duangmalai ◽

Peerawut Suwanjan

Keyword(s):

Integrated Circuit ◽

Universal Filter ◽

Differential Input ◽

First Order ◽

Voltage Mode ◽

Transconductance Amplifier ◽

Low Pass ◽

Simulation And Experiment ◽

Electronically Tunable ◽

High Pass

In this research contribution, the electronically tunable first-order universal filter employing a single voltage differencing differential input buffered amplifier (VD-DIBA) (constructed from two commercially available integrated circuit (IC): the operational transconductance amplifier, IC number LT1228, and the differential voltage input buffer, IC number AD830), one capacitor and two resistors. The features of the designed first order universal filter are as follows. Three voltage-mode first-order functions, low-pass (LP), all-pass (AP) and high-pass (HP) responses are given. The natural frequency (𝜔0) of the presented configuration can be electronically adjusted by setting the DC bias current. Moreover, the voltage gain of the LP and HP filters can be controllable. The phase responses of an AP configuration can be varied from 00 to −1800 and 1800 to 00. The power supply voltages were set at ±5 𝑉. Verification of the theoretically described performances of the introduced electronically tunable universal filter was proved by the PSpice simulation and experiment.

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