OTC-236 THERMOPILE INFRARED SENSOR ▓ Features The thermopile sensor consists of a series of 44 thermoelements, forming a sensitive area of 0.5*0.5 mm2. The sensor is hermetically sealed into a TO-5 metal housing, with an 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. ▓ 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 Parameter Condition Min. Typ. Max. Unit Number of thermojunctions --- 44 --- Chip size --- 1920*1725 --- µm2 --- 500*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 5-14µm filter 40 55 70 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 Measured at 1 Hz chopper frequency, within spectral range 5-14 µm, using a blackbody radiator of 500K temperature. ▓ Thermopile voltage vs. blackbody temperature ▓ Frequency response ▓ Field of view ▓ Pin assignment & description 1 thermopile output pin (+) 3 thermopile output pin (-) Thermopile 2(R) 3(V-) 1(V+) 4(GND) BACKSIDE VIEW SIDE VIEW ▓ Order information : OTC-236-AB A B ▓ : : 1 : standard filter (5-14 µm) 2 : silicon filter with flat band transmission 1 : window size = 2.57mm (diameter) 2 : window size = 3.80mm (diameter) Transmission of filter Transmission of optical filter is measured by FTIR from 2 µm ▓ Package The sensor is hermetically sealed into a TO-5 metal housing, with an 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. OTC-236-11 Unit: mm ψ8.15 2.00 ψ5.4 4.6 ψ2.57 Chip Cap Header 0.43 Window Window IR Filter IR filter OTC-236-12 Unit: mm 8.17 Chip Cap 2.00 4.6 ψ3.8 WIindow Windo filter IR ▓ Application circuit 0.43 Header Circuit 1 : +5V C1 R1 Thermopile R4 + R2 1 C3 R5 3 2 4 Vout + OP R6 C6 C4 C5 Reference Resistor R3 C2 Circuit 2 : Ambient Temperature Compensation Circuit Pre-Amplification Circuit +5V R10 + A2 Thermopile (+) - +5V Adder C1 C3 + A1 - Thermopile (-) R13 R11 1 + 3 - R1 R2 Vout R7 2 4 + A3 - R8 C2 reference resistor R9 R12 C4