mlx90615 Melexis Company, mlx90615 Datasheet - Page 18

• Manufacturer Part Number: mlx90615
• Description: Infra Red Thermometer
• Manufacturer: Melexis Company

8.6.2 Customizing the temperature range for PWM output
The calculated ambient and object temperatures are stored in RAM with a resolution of 0.02 °C (15 bit). The
PWM operates with a 10-bit number so the transmitted temperature is rescaled in order to fit in the desired
range.
For this goal 2 cells in EEPROM are foreseen to store the desired temperature range, PWM T min and PWM
T range.
Thus the output range can be programmed with an accuracy of 0.02 °C.
The data for PWM is rescaled according to the following equation:
The T
the result is a 10-bit word, in which 000h corresponds to PWM T
and 1LSB corresponds to
3901090615
Rev 001
T
T
T
PWM
MIN
MAX
EEPORM
EEPORM
RAM
=
T
is the linearized temperature, 15-bit (2D8A…4BD0h, 2D8A for -40°C and 4BD0h for +115°C) and
RAM
=
=
T
T
K
−
MIN
MAX
PWM
T
MIN
∗
∗
EEPROM
50
50
LSB
LSB
,
T
K
MAX
PWM
1023
−
To
=
T
MIN
RANGE
1023
[°C] , (T
EEPROM
Page 18 of 30
MAX =
T
MIN +
T
RANGE
MIN
[°C], 3FFh corresponds to PWM T
)
Infra Red Thermometer
MLX90615
Data Sheet
28/Aug/2008
MAX
[°C]