VOLTAGE MODE FIRST ORDER ALLPASS FILTER AND QUADRATURE OSCILLATOR EMPLOYING FULLY DIFFERENTIAL CURRENT FEEDBACK OPERATIONA

Abstract

A novel voltage-mode first-order all-pass filter configuration is proposed. The presented circuit uses single fully differential current feedback operational amplifier (FDCFOA), resistors and  capacitors.The output of the filter exhibits fully differential buffer circuit so that the synthesized filter can be cascaded without additional buffers. Furthermore the proposed circuit is suitable for wide range, low voltage and low power applications. To demostrate the performance of the proposed filter the voltage mode quadrature oscillators are given as an application example. They are implemented through the proposed FDCFOA based first order allpass filter and integrator as a building blocks. The theoretical results are verified with SPICE simulations using  CMOS realization of FDCFOA.