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
Thermopile
Number of thermojunctions --- 44 ---
Chip size --- 1920*1725 --- µm2
Active area Interference
layer --- 500*500 --- µm2
Thickness of substrate Silicon-
substrate 600 625 650 µm
Resistance of thermopile 25 °C 60 70 80 KOhm
Sensitivity With 5-14µm
filter 40 55 70 V/W
Detecctivity 4*1077*1079*107cm*Hz1/2/W
Time constant --- 30 --- Ms
Noise voltage --- 34 --- nV/Hz1/2
NEP --- 0.8 --- nW/Hz1/2
Temperature range Operation -20 --- 100 °C
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 : 1 : standard filter (5-14 µm)
2 : silicon filter with flat band transmission
B : 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
OTC-236-12
▓Application circuit
Window
IR
filter
ψ2.57
ψ5.4
ψ8.15
Window
IR Filter
Cap
Header
0.43
2.00
Unit: mm
4.6
Chip
Windo
IR
filte
r
ψ
3.8
8.17
WIindow
Unit: mm
Chip
Cap
Heade
r
2.00
4.6
0.43
Circuit 1 :
Circuit 2 :
C1 R1
C2
R2
2
4
R4
R3
+
-
1
3
C3
C4
R5 R6
+
OP
-
C6
C5
Vout
+5V
Reference
Resistor
Thermopile
R2
+5V
+
A1
-
+
A3
-
+
A2
-
+
-
Adder
Vout
C3
R9
R8
C2
Thermopile (-)
Thermopile (+)
R1
R7
C1
2
4
R13
R10
R11
R12
+5V
C4
reference
resistor
Ambient Temperature
Compensation Circuit
Pre-Amplification Circuit
1
3
