OTC-239 THERMOPILE INFRARED SENSOR ▓ Features The thermopile sensor consists of a series of 44 thermoelements, forming a sensitive area of 0.5 x 0.5 mm2. The sensor is hermetically sealed into a TO18 metal housing, with optical filter. This standard filter allows measurements to be made in the spectral range above 5 µm wavelength. The thermosensor exhibits an almost white noise, comparable to an ohmic resistance. It has a constant signal versus frequency up to its frequency limit, and is directly proportional to incident radiation. The thermopile sensors are featured with an additional thermistor on the same package. The standard version of thermistor is housing conneccted to ground. ▓ Applications * Ear thermometers; clinic thermometers * Infrared thermometers * Consumer applications: hair dryer, micro-wave oven, air conditioner, refrigerator * Continuous temperature control of manufacturing * Security system * Radiation monitor switch system * Absorbing measurement for gas analysis * Thermoelectric converter * Heat flux flowmeter ▓ Electrical Characteristics ROITHNER LASERTECHNIK Address Tel. No. Fax No. E-Mail http : : : : : Schoenbrunner Str. 7, 1040 Vienna, Austria 43-1-586 52 43-0 43-1-586 52 43-44 [email protected] www.roithner-laser.com page : 1 / 7 Parameter Condition Min. Typ. Max. Unit Number of thermojunctions --- 44 --- Chip size --- 1920 x 725 --- µm2 --- 500 x 500 --- µm2 Thermopile Active area Interference layer Thickness of substrate Siliconsubstrate 600 625 650 µm Resistance of thermopile 25 °C 60 70 80 KOhm Sensitivity With 5-14 µm filter 45 55 65 V/W 4*107 7*107 9*107 cm*Hz1/2/W Time Constant --- 30 --- ms Noise voltage --- 34 --- nV/Hz1/2 NEP --- 0.8 --- nW/Hz1/2 -20 --- 100 °C Detecctivity Temperature range Operation --- Temperature reference resistor Resistance (1) 25 °C 29.1 30.0 30.9 KOhm Resistance (2) 25 °C 97 100 103 KOhm Βvalue (1) 0oC/25 °C 3773 3811 3849 K Βvalue (2) 0oC/25 °C 3950 3970 3990 K Measured at 1 Hz chopper frequency, within spectral range 5-14 µm, using a blackbody radiator of 500 K temperature. Note : Thermistor should be operated under 1 mA. ▓ Thermopile voltage vs. blackbody temperature ROITHNER LASERTECHNIK Address Tel. No. Fax No. E-Mail http : : : : : Schoenbrunner Str. 7, 1040 Vienna, Austria 43-1-586 52 43-0 43-1-586 52 43-44 [email protected] www.roithner-laser.com page : 2 / 7 ▓ Frequency response ▓ Field of view ROITHNER LASERTECHNIK Address Tel. No. Fax No. E-Mail http : : : : : Schoenbrunner Str. 7, 1040 Vienna, Austria 43-1-586 52 43-0 43-1-586 52 43-44 [email protected] www.roithner-laser.com page : 3 / 7 ▓ Thermistor vs. temperature The resistance of the temperature reference resistor varies with temperature and the behaviour is illustrated in the following figure. 1 1 − β T T25 At temperature 25 °C, R(T)=R25e describes the resistance vs. temperature, ROITHNER LASERTECHNIK Address Tel. No. Fax No. E-Mail http : : : : : Schoenbrunner Str. 7, 1040 Vienna, Austria 43-1-586 52 43-0 43-1-586 52 43-44 [email protected] www.roithner-laser.com page : 4 / 7 where R25 is the resistance at ambient temperature 25 °C and T, T25 are the ambient temperatures in unit of kelvin degrees. ▓ Pin assignment & description 2 thermistor pin 4 thermistor pin (GND) 1 thermopile output pin (+) 3 thermopile output pin (-) Thermistor 2(R) 3(V-) 1(V+) 4(GND) BACKSIDE VIEW ▓ SIDE VIEW Order information : OTC-239-A A : 1 : standard filter (5-14 µm) 2 : silicon filter with flat band transmission ROITHNER LASERTECHNIK Address Tel. No. Fax No. E-Mail http : : : : : Schoenbrunner Str. 7, 1040 Vienna, Austria 43-1-586 52 43-0 43-1-586 52 43-44 [email protected] www.roithner-laser.com page : 5 / 7 Thermopile ▓ Transmission of filter Transmission of optical filter is measured by FTIR from 2 µm ▓ Package The sensor is hermetically sealed into a TO-18 metal housing, with optical filter. This standard filter allows measurements to be made in the spectral range above 5 µm wavelength. The dimensions of header and cap are shown below. Unit: mm 4.7000 CHIP CAP 3.6 HEADER 2.0 3.0000 WINDOW IR FILTER 0.43 ROITHNER LASERTECHNIK Address Tel. No. Fax No. E-Mail http : : : : : Schoenbrunner Str. 7, 1040 Vienna, Austria 43-1-586 52 43-0 43-1-586 52 43-44 [email protected] www.roithner-laser.com page : 6 / 7 ▓ Application circuit Circuit 1 : +5V C1 R1 Thermopile 2 4 R2 + - 1 C3 R5 3 Vout + OP R6 C6 C4 R4 C5 Reference Resistor R3 C2 Circuit 2 : Ambient Temperature Compensation Circuit Pre-Amplification Circuit +5V R10 + A2 Thermopile (+) - +5V Vout R7 Adder C1 C3 R11 1 + 3 - R1 + A1 - 2 4 R13 Thermopile (-) + A3 - R8 C2 reference resistor R9 R2 ROITHNER LASERTECHNIK Address Tel. No. Fax No. E-Mail http : : : : : Schoenbrunner Str. 7, 1040 Vienna, Austria 43-1-586 52 43-0 43-1-586 52 43-44 [email protected] www.roithner-laser.com page : 7 / 7 R12 C4