Ultra-low power CMOS voltage reference for high temperature applications up to 300°C

A voltage reference circuit dedicated for high temperature applications is presented. A high-temperature operation range up to 300°C and an ultra-low-power consumption of 6 μA @ 25°C and 18 μA @ 300°C are achieved by the presented new circuit which is implemented in 0.18 μm CMOS standard technology occupying layout area of 0.00063 mm². The proposed voltage reference is based on the weighted difference of the gate-sources of NMOS and PMOS transistors operating in weak-inversion region. A reference voltage of 1.375 V is obtained with a temperature coefficient of 25 ppm/°C in a wide temperature range from 0°C to 280°C and 89 ppm/°C @ 300°C. The measured noise densities with a 100nF filtering capacitor are 80 nV/sqrt Hz and 1 nV/sqrt Hz at 100 Hz and 100 kHz respectively, and with a power-supply rejection ration (PSRR) better than -33 dB at 10 MHz.