A New 7th-Order Log-Domain Elliptic Video Filter Using E-Cell Circuits Approach

This study proposes a new current-mode class-A log-domain elliptic filter for video frequency applications. The design is based on the topological simulation of the passive prototypes by using E-cells. The proposed filter has 3.42 MHz cut-off frequency with maximum 0.119 dB passband ripple and attenuation greater than 40 dB at 4.78 MHz. Only BJTs and grounded capacitors were implemented and operated with the symmetrical power supply of +/- 1.5 V. The cut-off frequency of the filter can be electronically tuned by changing external currents. SPICE simulations are given to confirm the theoretical design results. The proposed filter is simulated by using both idealized BJT models and AT&T CBIC-R type transistors.