10mhz cmos ota-c voltage-controlled quadrature oscillator

Abstract

A quadrature-type voltage-controlled oscillator with operational transconductance amplifiers and capacitors (OTA-C) is presented. A monolithic integrated CMOS test circuit is introduced to verify theoretical results. The attainable frequency range of oscillation of the chip test circuit is 3-10.34 MHz. The total harmonic distortion (THD) is 0.201.87% for corresponding peak-to-peak amplitude voltages between 100 mV and IV. This amplitude can be controlled either by using a diode connection of two MOS transistors or a proposed nonlinear resistor.