An on-chip CMOS relaxation oscillator with 29.69ppm/°C temperature coefficient

A temperature and supply independent on-chip relaxation oscillator is presented. This oscillator is designed in TSMC 180nm CMOS process with a supply voltage of 1.8V and consumes 98uW at 25MHz. Simulation results show that the oscillator exhibits frequency variation of 0.22% for supply changes from 1.62 to 1.98V, and 0.49% for temperature changes from -40°C to 125°C.