A novel current-mode multiphase sinusoidal oscillator using MO-CDTAs

Abstract

This article presents a novel current-mode multiphase sinusoidal oscillator. The oscillator can produce two groups of n output currents and one group of 2n output currents (n being even or odd) with equal amplitude and equal-phase space. The circuit only uses one multi-output current differencing transconductance amplifier and one grounded capacitor for each section, and is easy to integrate. Its oscillation condition and frequency can be electronically tuned linearly and independently, and its outputs possess high impedance. It is important that the multi-frequency oscillation in the oscillator is studied and a method for eliminating unnecessary oscillation is given. In addition, the inverting amplifier with the automatic gain control is employed to reduce the distortion of output signals. Finally, the frequency error is analysed and the simulated results are illustrated.

Keywords:

• multiphase sinusoidal oscillator
• multi-frequency oscillation
• current-mode circuit
• MO-CDTA

Acknowledgement

This study was supported by the Natural Science Foundation of the Education Bureau of Shaanxi Province, China (grant no. 2010JK889).