Integrated Sensor System for Humidity Sensing of Robots Using Analog Mixed CMOS Technology

Integrated humidity sensor system with Op amp was designed using analog mixed CMOS technology and their electrical properties were investigated. The integrated sensor system consisted of Wheatstone-bridge HUSFET (humidity sensitive field effect transistors) sensor blocks, a resistive humidity sensor block, a diode temperature sensor, and Op amp blocks. Simulated Op amp revealed that DC gain was over 84 dB, unity gain bandwidth was about 10 Mhz, and slew rate was over 10 V/uS. The drain current of an n-type HUSFET increased from 0.83 to 1.14 mA as relative humidity increases from 10 to 70 %RH..