An electronically tunable current-mode quadrature oscillator using PCAs

Abstract

The paper presents a new realization of active RC sinusoidal oscillator with electronically tunable condition and frequency of oscillation. As compared to the class of three resistors, two capacitors (3R-2C) based canonic oscillators, the proposed circuit here uses only two resistors and two capacitors as the passive components and still provides non-interactive tuning laws for the condition of oscillation (CO) and the frequency of oscillation (FO). The proposed circuit employs new bipolar programmable current amplifier (PCA) as the active building block and is capable of simultaneously providing two explicit quadrature current outputs. SPICE simulation results have been included to verify the workability of the circuit as an oscillator and the tuning range of the FO.