Realization of Tunable Elliptic Low-pass Filter based on CCCIIs

This article presents a realization of electronically tunable current-mode Elliptic ladder low-pass filter using CCCIIs. The passive RLC ladder filters prototype and signal flow graph method (SFG) are employed for synthesis. The CCCII-based lossy, lossless integrators and current attenuator are required for the circuit realization. The proposed filter circuit can be electronically tuned between 1 kHz and 1 MHz through bias current from 0.05 mu A to 50 mu A. The proposed filter use +/- 1.5V power supply with 6 mW power consumption at 50 mu A bias current. The proposed filter uses grounded capacitors without external resistors which is suitable for further integration. The total harmonic distortion (THD) of the low-pass filters is less than 0.5% over the operating frequency range. PSPICE simulation results are carried out, obtained by using BJT model parameter of HFA 3046, confirm the presented theory.