MLX90247

Discrete Infrared Thermopile Detectors Features and Benefits Solid state thermopile sensor On-chip thermistor for ambient temperature compensation High reliability and long-term stability Low cost, small size MLX90247 family Ordering Information P a rt N o MLX90247 Ta Suffix Package code E (-40C to +85C) SF (TO-39) Type D SA Notice: In case sensor is used in automotive applications, Melexis must be informed. D e s c r ip t io n La r g e a p e r t u r e t h e r m o p i l e d e t e c t o r w i t h o n-c h i p P T C t h e r m i s t o r , f l o a t i ng t h e r m o p i l e o u t p u t s . 3. 5 m m a p e r t u r e Applications Automotive contactless temperature sensing. IR thermometers Gas analysis equipment Occupancy detection 1. Functional Diagram 2. Description At the heart of the MLX90247 thermopile sensors is a silicon die with a central micromachined membrane surrounded by a bulk silicon edge. The hot junctions of the thermopile are positioned near the center of the membrane and the cold junctions are located above the bulk silicon edge. Infrared irradiation of the low thermal conductivity membrane creates a temperature difference between the membrane and the surrounding bulk silicon. The resulting thermopile voltage is a function of the temperature difference between the object and the sensor. Measurement of the absolute temperature of the object is possible by relating the thermopile signal to the temperature of the sensor. The exact temperature of the sensor is measured by a PTC thermistor integrated in the bulk silicon edge. No supply voltage is needed for the thermopile. The sensor and thermistor can be used independently of each other if desired, as the thermopile potential is floating. 60 kOhm 1 Out IR+ 40 uV/K 3 Out IR- Thermopile 2 Rsense 24 kOhm PTC Socket 4 VSS 3901090247 Rev. 004 Page 1 of 9 Data Sheet Oct/07 Discrete Infrared Thermopile Detectors Table of contents 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. FUNCTIONAL DIAGRAM..........................................................................................................1 DESCRIPTION..........................................................................................................................1 GLOSSARY OF TERMS ...........................................................................................................3 PIN DEFINITIONS AND DESCRIPTIONS .................................................................................3 MLX90247 SPECIFICATIONS...................................................................................................4 ABSOLUTE MAXIMUM RATINGS ............................................................................................5 UNIQUE FEATURES.................................................................................................................5 APPLICATIONS INFORMATION ..............................................................................................6 RELIABILITY INFORMATION...................................................................................................7 ESD PRECAUTIONS ................................................................................................................7 PACKAGE INFORMATION.......................................................................................................7 DISCLAIMER ............................................................................................................................9 MLX90247 family 3901090247 Rev. 004 Page 2 of 9 Data Sheet Oct/07 Discrete Infrared Thermopile Detectors MLX90247 family 3. Glossary of Terms IR: Infrared. Every object emits infrared radiation in relation to its temperature. This effect can be used to measure the temperature without the need for physical contact. PTC: On-chip thermistor which resistance increases with rising temperature (Positive Thermal Coefficient) tbb: Black body (object temperature) ta: Ambient (die) temperature 4. Pin Definitions and Descriptions TO-39 package - connections 1 P in 2 4 1 2 3 4 Sy m b o l O u tIr+ R s e ns Vs s D e s c r ip t io n I nf r a r e d T h e r m o p i l e p o s i t i v e o u t p u t O u tIr- T h e r m i s t o r g r o u nd / c a s e p o t e nt i a l I nf r a r e d T h e r m o p i l e ne g a t i v e o u t p u t T h e r m i s t o r - a m b i e nt ( d i e ) t e m p e r a t u r e s e ns o r 3 Top view = pins down 3901090247 Rev. 004 Page 3 of 9 Data Sheet Oct/07 Discrete Infrared Thermopile Detectors MLX90247 family 5. MLX90247 Specifications Operating temperature range: Ta = -40 to 85 ˚C unless otherwise noted Se ns i t i v e A r e a P a ra m e te r T y p ic a l 1. 2 x 1. 2 12 15 mm m U n it s 2 C o n d it io n W a v e l e ng t h r a ng e D C m e m b r a ne r e s p o ns i t i v i t y Se ns i t i v i t y ( A l p h a ) T h e r m o p ile o u t p u t v o lt a g e W i nd o w a p e r t u r e s i z e F ie ld o f v ie w Sp e c t r a l s e ns i t i v i t y T h e r m o p i l e R e s i s t a nc e N o is e NEP 5 .5 … 4. 28 46 ±25 % x 10-13 V/K4 mm V V/W ±25 % 3. 5 88 > 70