The MLX90614 is built from 2 chips developed and manufactured by Melexis:

•

The Infra Red thermopile detector MLX81101

•

The signal conditioning ASSP MLX90302, specially designed to process the output of IR sensor.  

The device is available in an i

ndustry standard TO-39 package.  

Thanks   to   the   low   noise   amplifier,   high   resoluti

on   17-bit   ADC   and   powerful   DSP   unit   of   MLX90302   high  

accuracy and resolution of the thermometer is achiev

ed. The calculated object and ambient temperatures are

available   in   RAM   of   MLX90302   with   resolution   of   0.01  

̊

C.   They   are   accessible   by   2   wire   serial   SMBus  

compatible protocol (0.02°C resolution) or via 10-bi

t PWM (Pulse Width Modulated) output of the device.

The MLX90614 is factory calibrated in wide temperature ranges: -40 to 125

̊

C for the ambient temperature

and   -70   to   382.2  

̊

C   for   the   object   temperature.   The   10-bit   PWM  

is   as   a   standard   configured   to   transmit  

continuously   the   measured   object   temperature   for   an   object   temperature   range   of   -20   to   120  

̊

C   with   an  

output   resolution   of   0.14  

̊

C.    The   PWM   can   be   easily   customiz

ed   for   virtually   any   range   desired   by   the  

customer   by   changing   the   content   of   2   EEPROM   cells.   

This   has   no   effect   on   the   factory   calibration   of   the  

device.

The   PWM   pin   can   also   be   configured   to   act   as   a   thermal   relay   (input   is   To),   thus   allowing   for   an   easy   and  

cost   effective   implementation   in   thermostats   or   te

mperature   (freezing/boiling)   alert   applications.   The   

temperature   threshold   is   user   programmable.   In   an  

SMBus   system   this   feature   can   act   as   a   processor  

interrupt that can trigger reading all slaves

on the bus and to determine the precise condition.

As   a   standard,   the   MLX90614   is   calibrated   for   an   object  

emissivity   of   1.   It   can   be   easily   customized   by   the  

customer for any other emissivity

in the range 0.1-1.0 without the need

of recalibration with a black body.

The thermometer is available in 2 supply voltage options: 5V compatible or 3V (battery) compatible. The 5V

can   be   easily   adopted   to   operate   from   a   higher   supply   voltage   (8-16V,   for   example)   by   use   of   few   external  

components (refer to “Applications

information” section for details).

An   optical   filter   (long-wave   pass)   that

  cuts   off   the   visible   and   near   infra-

red   radiant   flux   is   integrated   in   the  

package to provide sunlight imGeneral description (continued)