Current and Voltage Mode Resistorless Universal Biquad Filter Using a Single CCCDTA

摘要

Current mode (CM) Single-input and multi-output (SIMO) and Voltage mode (VM) Multi-input and single-output (MISO) biquad filters are proposed. The presented configurations use one Current controlled current differencing transconductance amplifier (CCCDTA) and two capacitors without any external resistors, which is easy suited for integrated circuit fabrication. The current mode filter can realize the second-order low pass, band pass, high pass and band stop responses simultaneously. And the voltage-mode filter can realize all the standard filtering functions from the same structure. The natural frequency (omega) and quality factor (Q) of the filters can be controlled electronically by transconductance of the CCCDTA. Moreover, the proposed filters does not require any impedance matching due to its two input resistance can be independently tuned through the diverse external bias currents of CCCDTA. The influences of the CCCDTA non-idealities are also analyzed and both the active and passive sensitivities are considerably low. This design was simulated in PSPICE. Simulation results showed that their performances in power, bandwidth, out-band rejection and in-band ripple are better than the traditional. Additionally, the experiment results are provided in the paper.