A low power consumption CMOS differential-ring VCO for a Wireless Sensor

This paper describes a three-stage Voltage Controlled ring Oscillator (VCO) based on 0.35 μm CMOS standard technology. The VCO was designed for a transmitter operating in the 863-870 MHz European band for Wireless Sensor applications. A voltage V
_CTRL
controls the oscillation frequency of the VCO. Simulation results of the fully differential VCO with positive feedback show that the estimated power consumption, at desired oscillation frequency and under a supply voltage of 3.3 V, is only 7.48 mW. The proposed VCO exhibits a phase noise lower than -126 dBc/Hz at 10 MHz offset frequency.