Low Power XNOR based Single Ended VCO Circuit Design with Dynamic Threshold MOS

This paper proposes a single-ended voltage-controlled oscillator (VCO) circuit design using XNOR gate as the basic delay element and dynamic threshold MOS (DTMOS) as the tuning element at the output node of the delay stage. The proposed PN-DTMOS ring oscillator achieves a frequency tuning range of 4.41 GHz to 4.05 GHz with variations in tuning voltage from 0V to 0.7V. The power dissipation of the proposed VCO is as low as 1.071 mW. This VCO achieves a frequency tuning range of 1.46 GHz to 4.12 GHz and power dissipation in the range of 0.123 mW to 1.067 mW with variations in power supply voltage from 1V to 1.8V. Proposed VCO shows a phase noise of -72.88 dBc/Hz@1MHz with the figure of merit (FoM) of -152.52 dBc/Hz with PN-DTMOS varactor tuning. This new approach using the forward body biasing technique can adjust the transistor’s threshold voltage.