MLX90614_15 Datasheet, PDF (34/51 Pages) Melexis Microelectronic Systems – Single and Dual Zone Infra Red Thermometer in TO-39

MLX90614 family
Single and Dual Zone
Infra Red Thermometer in TO-39
dependence comes from the ambient temperature it is the same for all type of devices regardless of FOV and
optics used and it directly translates in the same compensation for object temperature.
The typical VDD dependence of the ambient and object temperature is 0.6°C/V.
Typical Ta=f(VDD) dependance
0.50
0.40
0.30
0.20
0.10
0.00
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
-0.10
-0.20
-0.30
-0.40
-0.50
VDD, V
Sensor1
Sensor2
Sensor3
Sensor4
Sensor5
Sensor6
Sensor7
Sensor8
Sensor9
Sensor10
Sensor11
Sensor12
Sensor13
Sensor14
Sensor15
Sensor16
Figure 24: Typical Ta dependence from supply voltage
Example: As the devices are calibrated at VDD=3V the error at VDD=3V is smallest one. The error in ambient
channel is directly transferred as object channel error (see Figure 25 bellow).
Typical To=f(VDD) dependance
0.50
0.40
0.30
0.20
0.10
0.00
2.2
2.4
2.6
2.8
3.0
3.2
3.4
3.6
3.8
-0.10
-0.20
-0.30
-0.40
-0.50
VDD, V
Sensor1
Sensor2
Sensor3
Sensor4
Sensor5
Sensor6
Sensor7
Sensor8
Sensor9
Sensor10
Sensor11
Sensor12
Sensor13
Sensor14
Sensor15
Sensor16
Figure 25: Typical To dependence from supply voltage (practically the same as Ta dependence error
In order to compensate for this error we measure supply voltage and by applying following equation
compensate the result.
T_{O _ compensated} = T_O − (VDD − VDD₀ ) × Typical _ dependence = T_O − (VDD − 3) × 0.6
Compensated VDD dependence
0.5
0.4
0.3
0.2
0.1
0
2.2
2.4
2.6
2.8
3
3.2
3.4
3.6
3.8
-0.1
-0.2
-0.3
-0.4
-0.5
VDD, V
Sensor1
Sensor2
Sensor3
Sensor4
Sensor5
Sensor6
Sensor7
Sensor8
Sensor9
Sensor10
Sensor11
Sensor12
Sensor13
Sensor14
Sensor15
Sensor16
Figure 26: Typical To compensated dependence error
3901090614
Rev 009
Page 34 of 52
Data Sheet
June 29, 2015