MLX90614 family
Single and Dual Zone
Infra Red Thermometer in TO-39
General description (continued)
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 industry standard TO-39 package.
Thanks to the low noise amplifier, high resolution 17-bit ADC and powerful DSP unit of MLX90302 high
accuracy and resolution of the thermometer is achieved. 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-bit 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 customized 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 temperature (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 immunity.
3901090614
Rev 003
Page 2 of 40
Data Sheet
03/Oct/2007
MELEXIS [ Melexis Microelectronic Systems ]
