Three Input One Output Current-Mode Cascadable Universal Filter Employing CDTAs
N. A. Shah, Munazah Quadri and S. Z. Iqba
A novel electronically tunable current-mode three input and a single output universal filter based on and employing three current differencing transconductance amplifiers, two grounded capacitors which are ideal for integration and a single grounded resistor is presented. The circuit is capable of realizing all the five generic filtering functions without requiring change in the circuit topology or nature of components or additional components except for allpass function. The circuit permits cascadibility as it offers low input and high output impedances. The natural frequency wo and quality factor Q are independently and electronically tunable. The circuit has the added advantage of offering independent gain adjustment without disturbing the filtering parameters. PSPICE simulation results are included to confirm the workability of the filter.
Keywords: Analog signal processing circuits, Current-mode active filters, Current differencing transconductance amplifier.