Solid state sensor
High reliability
Low cost, small size
On chip temperature sensor
Applications
Non-Contact Temperature Sensing
Differential Temperature Sensing
Climate Control
Ear, Temple Th ermometers
Household and Commercial Appliances
Ordering Information
Part No.Description
MLX90247CThermopile with 100K NTC Thermistor
MLX90247C
Thermopile w/NTC Thermistor
Functional Diagram
ϑ
−
Description
The MLX90247C is a thermopile sensor IC which
detects very small amounts of heat radiation. The
sensor consists of a membrane with a thermopile on
top of it.
The hot junctions of the thermopile are positioned
near the center of the membrane, the cold junctions
above the bulk silicon edge.
Due to the low thermal conductivity of the
membrane, absorbed heat will cause the
temperature to increase more at the center of the
membrane than at the edge above the bulk. This
temperature difference is converted to an electric
potential by the thermo-electric effect in the
thermopile junctions. No supply voltage is needed.
The sensor IC is packaged together with a NTC chip
thermistor for cold junction reference. The
thermopile and thermistor are separate components,
mounted in close proximity. The NTC thermistors
have higher sensitivity at low temperatures than the
standard PTC thermistors in the B and D models.
The sensor and thermistor can be used independent
of each other if desired, as the thermopile potential
is floating.
MLX90247C Discrete Infrared Sensor IC Page 1 Rev 1.0 17/Feb/01
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MLX90247C
Thermopile w/NTC Thermistor
MLX90247C Electrical Specifications
DC Operating Parameters TA = -40oC to 150oC, (unless otherwise specified)
ParameterSymbolTest ConditionMinTypMaxUnit
Thermopile ResistanceRtp@298K4459.575
SensitivityS
TC of SensitivityTCs@298K0.1%/K
Time constantT30ms
Thermistor ValueRntc
Thermal Coefficient NTC
(1) Tolerance given between 15°C and 35°C. Typical value corresponds to a relative resistance change of
–4.68%/°C. Definition of β is ∆lnR/∆(1/T) with T in K. (Naperian logarithm).
Note: when measuring resistances with an ohm meter, please take care that the internal protection diodes,
as indicated in the functional diagram below, are always reverse biased.
(1)
ntc0-50°C
β
sensor @298K
black body @299K
@298K
(1)
294255
95100105
412041404161K
k
Ω
V/K
µ
k
Ω
−
ϑ
MLX90247C Absolute Maximum Ratings
ParameterValueUnitComment
Operating temperature-40 ~ 150°CKeep diode leakage in mind at high temperatures
Storage temperature-40 ~ 150°C
Soldering temperature<220°Ct<5sec
MLX90247C Discrete Infrared Sensor IC Page 2 Rev 1.0 17/Feb/01
Page 3
Thermopile w/NTC Thermistor
MLX90247C Pinout
PinSymbolDescription
1OutIr+Infrared Thermopile positive output
2RsensThermistor for sensor ambient temperature measurement
3OutIr-Infrared Thermopile negative output
4VssThermistor ground / case potential
TO-39 package - connections
1
MLX90247C
2
3
Top view = pins down
ML90247C Mechanical Specifications
ParameterValueUnitComment
TO-39 specifications
Metal capWelded
Filling gasNitrogen
Filter specifications
Transmission>75%
Transmission<0.5%
Sensor window
FOV100°Full opening angle: Determined by aperture
Aperture diameter3.5mmDefault
7.5µ < λ <13.5
0 < λ < 5
4
µ
µ
ESD Precautions
ESD control procedures whenever handling semiconductor devices.
Disclaimer
included herein is believed to be accurate and reliable. However, Melexis assumes no responsibil ity f or its use; nor for
any infringements of patents or other rights of third parties which may result from it’s use.
MLX90247C Discrete Infrared Sensor IC Page 3 Rev 1.0 17/Feb/01
Electronic semiconductor products are sensitive to Electro Static Discharge (ESD). Always observe
Melexis reserves the right to periodically make modifications to product specificat i ons. The informatio n
Page 4
RA (TO-39) Package Outline
MLX90247C
Thermopile w/NTC Thermistor
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