CFOA-based single resistance controlled quadrature oscillator

This paper presents a new single-resistance-controlled (SRC) sinusoidal quadrature oscillator with reduce number of passive elements using only two current-feedback operational amplifiers (CFOAs). The proposed oscillator configuration comprising two CFOAs, three resistors and two capacitors provides two sinusoidal voltage outputs in phase quadrature. The circuit has the advantage of independent control of the condition of oscillation and the oscillation frequency through a single resistor. In addition, both proposed circuit configurations have good active and passive sensitivity performance. PSPICE simulation results based on commercially available AD844-type CFOAs are also included, showing the excellent performance of the proposed oscillator configuration. © 2008 SICE.