Design of current-mode multiphase sinusoidal oscillators using CDCTA with independent control of CO and FO

An implementation of current-mode multiphase sinusoidal oscillators (MSOs) is presented. The odd and odd/even phase systems can be realised using current differencing cascaded transconductance amplifier (CDCTA)-based lossy integrators. The condition of oscillation and frequency of oscillation can be controlled electronically and independently through adjusting the current of the CDCTA. The high output impedances facilitate easy driving an external load without additional current buffers. The proposed MSOs provide odd or even phase signals that are equally spaced in phase and equal amplitude. The circuit requires one CDCTA and one grounded capacitor per phase without external resistor and additional current amplifier. The results of PSPICE simulations using BJT CDCTA are included to verify theory.