MLX9O247 Infrared Sensor IC

The MLX90247 family sensors are thermopile sensors detecting very small amounts of heat radiation. The sensors consist of a membrane with a thermopile on top of it. The hot junctions of the thermopile are positioned near the center of the membrane and the cold junctions above the bulk silicon edge. Due to the low thermal conductivity of the membrane, absorbed heat will cause the temperature of the membrane to increase above the temperature of the surrounding bulk silicon. This temperature difference is converted into an electric potential by the thermo-electric effect in the thermopile junctions. No supply voltage is needed.
The MLX90247 can be used to detect thermal radiation from a distance. The output signal is an analog voltage that is uncalibrated.
To make a non contact IR thermometer the MLX90614 should be used as this thermometer -while looking exactly like the MLX90247- generates a linearized and calibrated temperature reading.