VOLTAGE CONTROLLED OSCILLATOR WITH BODY BIAS CONTROLLING

摘要

A voltage controlled oscillator with body bias controlling is provided to obtain a gain at low power consumption and to prevent the degradation of performance due to the variation of process and temperature by sensing and feeding back an oscillation operation. A resonant circuit part(100) generates a resonant frequency according to a tuning voltage. A differential oscillation part(200) supplies energy to the resonant circuit part by being differentially cross-coupled to the resonant circuit part, and outputs first and second oscillation signals of phase difference of 180 degrees by oscillating the resonant frequency of the resonant circuit part, and includes first and second transistors controlling the level of the first and second oscillation signal constantly according to a body bias voltage. An output level detection part(300) detects the level of the first and second oscillation signal of the differential oscillation part, and supplies the body bias voltage to each body of the first and second transistors.