An RC oscillator with temperature compensation for accurate delay control in electronic detonators

An on-chip RC oscillator in electronic detonators, whose frequency is stable with temperature and supply voltage variation, is presented in this paper. As a critical part in the oscillator, a current reference with second-order temperature compensation is proposed. Some modifications to the topology of the RC oscillator are also presented to achieve better accuracy. The circuit is designed in 0.18¿m CMOS technology. Simulation results show that the current reference has a temperature coefficient of only 2.48 ppm/°C and the maximum fluctuation of the RCO frequency is less than 0.093% in the temperature range of -30~110°C and the supply voltage range of 3.1~3.5V.