THERMOELECTRIC AC POWER SENSOR BY CMOS TECHNOLOGY

We report the first thermoelectric ac power sensor (thermoconverter) realized by industrial CMOS IC technology in combination with postprocessing micromachining. The sensor is based on a polysilicon heating resistor and a polysilicon/aluminum thermopile integrated on an oxide microbridge. The thermopile sensitivity is 9.9 mV / mW and the burn-out power of the sensor is 50 mW. The time constant is 1.85 ms and the signal-to-noise ratio is 8 . 10(9) / W. The linearity error with respect to frequency is less then 0.1% below 400 MHz and less than 1% up to 1.2 GHz.