The STP11DF85G1 comprising a new type CMOS compatible thermopile sensor chip features good sensitivity, small temperature coefficient of sensitivity as well as high reproducibility and reliability. An 8~14 um band pass filter in front of the sensor makes the device sensitive to high temperature up to 1500°C. An ASIC AFE (Analog Front End) chip is integrated with the thermopile sensor, providing 1000 or 2000 gain for the small voltage output of thermopile sensor. A input offset voltage is also added in the sensor input. The sensor output voltage can be directly converted by ADC, which elimates the precision Zero-Drift amplifier and DC-DC circuit. A high-precision thermistor reference chip is also integrated for ambient temperature compensation.