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 0.18μm 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.
['Ahmad Hassan', 'Benoit Gosselin', 'Mohamad Sawan']
Ultra-low power CMOS voltage reference for high temperature applications up to 300°C