An ultra-low power switch array of temperature and humidity sensors with direct digital output

This paper reports an ultra-low power cantilever switch array of temperature and humidity sensors with direct digital output. The sensors are designed to measure a temperature range of -40~150°C and a relative humidity range of 20~95%. The direct digital output precludes any need for power demanding analog-to-digital conversion circuitry. A redundancy is employed in the sensor design for the yield enhancement of low-cost sensor fabrication. The fabricated sensors have been tested and characterized in an environment chamber. Test results indicate that both temperature sensor array and humidity sensor array have the desired response temperature and humidity.