MLX90616 Datasheet, PDF (22/36 Pages) Melexis Microelectronic Systems – Infra Red Thermometer in TO-39 for high temperature thermometer guns

MLX90616ESF-HCA
Infra Red Thermometer in TO-39
for high temperature thermometer guns
8.5.2 Customizing the temperature range for PWM output
The calculated ambient and object temperatures are stored in RAM with a resolution of 0.02 °C (16 bit). The
PWM operates with a 10-bit word so the transmitted temperature is rescaled in order to fit in the desired
range.
For this goal 2 cells in the EEPROM are foreseen to store the desired range for To (To_min and To_max) and one
for Ta (Ta_range: the 8MSB are foreseen for Ta_max and the 8LSB for Ta_min).
Thus the output range for To can be programmed with an accuracy of 0.02 °C, while the corresponding Ta
range can be programmed with an accuracy of 0.64 °C.
The object data for PWM is rescaled according to the following equation:
T  ^T _K^{ T} , K  ^T ₁₀^₂₃^T _PWMobj
RAM
MIN _{EEPRO M}
PWM obj
PWM obj
MAX _EEPROM
MIN _{EEPRO M}
The T_RAM is the linearized Tobj, 16-bit (0x0000…0xFFFF, 0x0000 for -273.15°C and 0xFFFF for +1037.55°C)
and the result is a 10-bit word, in which 0x000h corresponds to To_MIN[°C], 0x3FFh corresponds to To_MAX[°C]
and 1LSB corresponds to ^{ToMAX  ToMIN} [°C]
1023
T_MINEEPORM  T_MIN  50 LSB
T_MAXEEPORM  T_MAX  50 LSB
The ambient data for PWM is rescaled according to the following equation:
T  ^T _K^{ T} , K  ^T ₁₀^₂^T_{3 PWMambient}
RAM
MIN _{EEPRO M}
PWM_{a m b ien t}
PWM ambient
MAX _EEPROM
MIN _{EEPRO M}
The result is a 10-bit word, where 000h corresponds to -38.2 °C (lowest Ta that can be read via PWM), 3FFh
corresponds to 125 °C (highest Ta that can be read via PWM) and 1LSB corresponds to ^{TMAX  TMIN} [°C]
1023
   T_MINEEPORM  T_MIN   38.2
 ¹⁰⁰ LSB
64
   T_MAXEEPORM  T_MAX   38.2
 ¹⁰⁰ LSB
64
3901090616
Rev 002
Page 22 of 36
Data Sheet
August 20, 2012