A Submicrowatt 1.1-MHz CMOS Relaxation Oscillator With Temperature Compensation

A 1.1-MHz submicrowatt current-mode relaxation oscillator with temperature compensation is presented. In this oscillator, the current-starving inverters are biased by using the current sources with positive and negative temperature coefficients. It relaxes the temperature variations. This oscillator is fabricated in a 0.18- μm CMOS process, and its area is 0.075 mm². The power consumption is 0.859 μW, with a supply voltage of 1.8 V, and the calculated figure of merit is 0.78 nW/kHz. The measured output relative frequency variation is less than 3%/V for the supply voltage of 1.2-2.4 V and ±0.5% for the temperature of -20°C-80°C. The average temperature coefficient is 64.3 ppm/°C.