Voltage Tunable Building Blocks Using Compact Active Device in Design of Filtering Applications

This paper introduces new application of the modern advanced active device VCA822 in building blocks (integrators, differentiators) of voltage-mode multifunctional filters having electronically tunable properties. Implementation of active device brings simplification of the topology and signal operations that are available directly (without opamp-based summing amplifier), electronic tunability and high-input and low-output impedances. The topology of proposed filter has several useful modifications that are explained, theoretically described and verified by PSpice simulations. The design verification has been performed in band of hundreds of kHz while band-pass response was tuned by DC voltage between 171 kHz and 1 959 kHz.