A 0.6V LC-VCO with High Immunity to Threshold Voltage Variation

a low-voltage low-power LC voltage controlled oscillator (VCO) with robust performance against threshold voltage variations is presented in this work. A simple body controlling circuit is used for suppressing the threshold voltage variations through changing the body voltage of the VCO’s transistors. The sensitivity of the normalized phase noise and output voltage swing of the VCO with the body controlling circuit under 0.16% threshold voltage shift decreases as nearly 9.5 times and 5.7 times compared to the VCO with constant body bias, respectively. Furthermore, the supply voltage and the power consumption of the designed VCO are decreased by the body controlling circuit. The power consumption of the proposed VCO is 0.387mW under 0.6V supply voltage. Moreover, the traditional tail current source is removed that leads the VCO to exhibit a larger swing. The circuit operation is investigated by analytical equations and it is verified by the simulation results in the 180nm CMOS process.

Keywords:

Threshold voltage variation , LC-VCO , body controlling , low-voltage