A temperature-stable Low-Power Wide-Range CMOS Voltage Controlled Oscillator Design for Biomedical Applications

This paper presents a low power temperature compensated CMOS ring oscillator for biomedical applications across a wide temperature range. The proposed circuit deploys an IPTAT (inversely proportional to absolute temperature) bias current by generating an adaptive control voltage in each stage of the oscillator to compensate the overall oscillator's temperature coefficient (TC). Simulations using TSMC 0.18 mu m CMOS technology show that this configuration can achieve a frequency variation less than 0.25%, leading to an average frequency drift of 20.83 ppm/degrees C. Monte Carlo simulations have also been performed and demonstrate a 3 sigma deviation of about 2.15%. The power dissipated by the proposed circuit is only 8.48 mW at 25 degrees C.