Cascadable all-pass and notch filter configurations employing two plus-type DDCCs

Abstract

In this paper, twelve new circuit configurations for realization of first-order, second-order voltage-mode all-pass and notch filters with high input impedance and low output impedance are presented. The proposed circuit configurations use two plus type DDCCs, and two impedances. The circuits use one grounded capacitor and two grounded resistors for realizing first-order all-pass filters, and two grounded capacitors and two resistors for realizing second-order all-pass/notch filters. High input impedance and low output impedance of the configuration enable the circuits to be cascaded without additional buffers. As an application, a quadrature oscillator is realized. The theoretical results are verified with PSPICE simulations using 0.5 μm CMOS parameters. © 2011 World Scientific Publishing Company.