A low-voltage voltage-controlled ring-oscillator employing dynamic-threshold-MOS and body-biasing techniques

In this paper a four-stage self-biased voltage-controlled oscillator (VCO) is presented. The proposed ring-oscillator circuit employs a combination of dynamic-threshold-MOS (DT-MOS) and bulk-driven transistors to design low-voltage low-power VCO with high oscillation frequency. By using an auxiliary body-driven latch, the VCO achieves a wide operating frequency range from 0.88 to 1.36 GHz (more than 40% tuning range). Simulation results in a 65-nm CMOS technology shows frequency variations of 3% against temperature variation of -20 °C to 85 °C, with only 0.36 mW power consumption using a 0.7 V supply voltage.