OTC-238

OTC-238 THERMOPILE INFRARED SENSOR Date : Oct. 10, 2000 ▓ 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-18 metal housing, with optical filter. This standard filter allows measurements to be made in the spectral range above 5µm 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 Thermopile Number of thermojunctions Chip size Active area Condition Min. Typ. Max. Unit ----Interference layer Siliconsubstrate 25 With 5-14µm filter --- 44 1920*1725 500*500 ------µm2 µm2 Thickness of substrate Resistance of thermopile Sensitivity Detecctivity Time Constant Noise voltage NEP Temperature range 600 60 40 4*107 ------- 625 70 55 7*107 30 34 0.8 --- 650 80 70 9*107 ------100 µm KΩ V/W cm*Hz1/2/W ms nV/Hz1/2 nW/Hz1/2 Operation -20 Measured at 1 Hz chopper frequency, within spectral range 5-14µm, using a blackbody radiator of 500K temperature. ▓ Thermopile voltage vs. blackbody temperature ▓ Frequency response ▓ Field of view ▓ Pin assignment & description 1 3 thermopile output pin (+) thermopile output pin (-) Thermopile 2(R) 3(V-) 1(V+) 4(GND) BACKSIDE VIEW SIDE VIEW ▓ Order information : OTC-238-A A : 1 2 : : standard filter (5-14µm) silicon filter with flat band transmission ▓ Transmission of filter Transmission of optical filter is measured by FTIR from 2µm ▓ 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 5µm wavelength. The dimensions of header and cap are shown below. 4.7000 3.0000 WINDOW IR FILTER 0.43 Unit: mm 2.0 CHIP CAP 3.6 HEADER ▓ Application circuit Circuit 1 : +5V C1 R1 Thermopile 1 3 C3 R5 C4 C5 + OP R6 Vout C6 R4 + R2 2 4 Reference Resistor R3 C2 Circuit 2 : Pre-Amplification Circuit Ambient Temperature Compensation Circuit +5V R10 + A2 Thermopile (+) R7 Adder C1 C3 R13 R11 2 4 + A3 R8 C2 R9 reference resistor Vout C4 +5V R1 + A1 R2 1+ 3Thermopile (-) R12