1.2 MHz relaxation oscillator with 16.8 ppm/°C temperature coefficient using resistive self-bias current

In this research, the authors propose a self-biased relaxation oscillator that outputs a constant 1.2 MHz clock over a wide temperature range. Excluding any external bias, the proposed oscillator embodies a self-bias circuit that generates a bias current from a precisely trimmed resistor. To minimise the power consumption, a switched-bias technique was applied to the two comparators in the oscillator. The proposed circuit was fabricated in a 180 nm CMOS process. It consumes 17.9 µW from a 1.5 V supply, and its temperature coefficient is 16.8 ppm/°C in the range of −20-80°C.