MLX90614 family
Single and Dual Zone
Infra Red Thermometer in TO-39
Features and Benefits
Small size, low cost
Easy to integrate
Factory calibrated in wide temperature range:
-40…+125˚C for sensor temperature and
-70…+380˚C for object temperature.
High accuracy of 0.5°C in a wide temperature
range (0…+50°C for both Ta and To)
High (medical) accuracy calibration
Measurement resolution of 0.02°C
Single and dual zone versions
SMBus compatible digital interface
Customizable PWM output for continuous
reading
Available in 3V and 5V versions
Simple adaptation for 8…16V applications
Sleep mode for reduced power consumption
Different package options for applications and
measurements versatility
Automotive grade
Applications Examples
High precision non-contact temperature
measurements
Thermal Comfort sensor for Mobile Air
Conditioning control system
Temperature sensing element for residential,
commercial and industrial building air
conditioning
Windshield defogging
Automotive blind angle detection
Industrial temperature control of moving parts
Temperature control in printers and copiers
Home appliances with temperature control
Healthcare
Livestock monitoring
Movement detection
Multiple zone temperature control – up to 127
sensors can be read via common 2 wires
Thermal relay / alert
Body temperature measurement
Ordering Information
Temperature
Package
- Option Code
Standard Packing
Code
Code
part
form
-X X X
MLX90614
SF (TO-39)
(1) (2) (3)
-000
-TU
E (-40°C...85°C)
K (-40°C…125°C)
(1) Supply Voltage/ Accuracy
(2) Number of thermopiles:
(3) Package options:
A - 5V
A – single zone
A – Standard package
B - 3V
B – dual zone
B – Reserved
C - Reserved
C – gradient compensated* C – 35° FOV
D - 3V medical accuracy
D/E – Reserved
F – 10° FOV
G – Reserved
H – 12° FOV (refractive lens)
I – 5° FOV
Example:
MLX90614ESF-BAA-000-TU
* : See page 2
Part No.
1 Functional diagram
MLX90614Axx: Vdd=4.5...5.5V
J1
1
MLX90614
SCL
U1
SCL
Vz
2 General Description
The MLX90614 is an Infra Red thermometer for non
contact temperature measurements. Both the IR sensitive
thermopile detector chip and the signal conditioning ASSP
are integrated in the same TO-39 can.
Thanks to its low noise amplifier, 17-bit ADC and
powerful DSP unit, a high accuracy and resolution of the
thermometer is achieved.
The thermometer comes factory calibrated with a digital
PWM and SMBus (System Management Bus) output.
As a standard, the 10-bit PWM is configured to
continuously transmit the measured temperature in range
of -20…120˚C, with an output resolution of 0.14˚C.
The factory default POR setting is SMBus.
SDA
Vdd
GND
PWM
2 SDA
Vdd
3
Vss 4
C1
0.1uF
CON1
C1 value and type may differ
in different applications
for optimum EMC
MLX90614 connection to SMBus
Figure 1: Typical application schematics
3901090614
Rev 009
Page 1 of 52
Data Sheet
June 29, 2015
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…125˚C for the ambient
temperature and -70…380˚C for the object temperature.
The measured value is the average temperature of all objects in the Field Of View of the sensor. The
MLX90614 offers a standard accuracy of ±0.5˚C around room temperatures. A special version for medical
applications exists offering an accuracy of ±0.2˚C in a limited temperature range around the human body
temperature.
It is very important for the application designer to understand that these accuracies are only guaranteed
and achievable when the sensor is in thermal equilibrium and under isothermal conditions (there are no
temperature differences across the sensor package). The accuracy of the thermometer can be influenced by
temperature differences in the package induced by causes like (among others): Hot electronics behind the
sensor, heaters/coolers behind or beside the sensor or by a hot/cold object very close to the sensor that not
only heats the sensing element in the thermometer but also the thermometer package.
This effect is especially relevant for thermometers with a small FOV like the xxC and xxF as the energy
received by the sensor from the object is reduced. Therefore, Melexis has introduced the xCx version of the
MLX90614. In these MLX90614xCx, the thermal gradients are measured internally and the measured
temperature is compensated for them. In this way, the xCx version of the MLX90614 is much less sensitive to
thermal gradients, but the effect is not totally eliminated. It is therefore important to avoid the causes of thermal
gradients as much as possible or to shield the sensor from them.
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 10-bit PWM is as a standard configured to transmit continuously the measured object temperature
for an object temperature range of -20…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 a 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.
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 ambient and sunlight immunity. The wavelength pass band of this optical filter is from
5.5 till 14µm (except for xCH and xCI type of devices which incorporate uncoated silicon lens).
3901090614
Rev 009
Page 2 of 52
Data Sheet
June 29, 2015
MLX90614 family
Single and Dual Zone
Infra Red Thermometer in TO-39
3 Table of Contents
1 Functional diagram ..................................................................................................................................................................................... 1
2 General Description .................................................................................................................................................................................... 1
3 Table of Contents ....................................................................................................................................................................................... 3
4 Glossary of Terms ...................................................................................................................................................................................... 4
5 Maximum ratings ........................................................................................................................................................................................ 4
6 Pin definitions and descriptions................................................................................................................................................................... 5
7 Electrical Specifications .............................................................................................................................................................................. 6
7.1 MLX90614Axx ..................................................................................................................................................................................... 6
7.2 MLX90614Bxx, MLX90614Dxx ............................................................................................................................................................ 8
8 Detailed description .................................................................................................................................................................................. 10
8.1 Block diagram ................................................................................................................................................................................... 10
8.2 Signal processing principle ................................................................................................................................................................ 10
8.3 Block description ............................................................................................................................................................................... 11
8.3.1 Amplifier..................................................................................................................................................................................... 11
8.3.2 Supply regulator and POR ......................................................................................................................................................... 11
8.3.3 EEPROM ................................................................................................................................................................................... 11
8.3.4 RAM........................................................................................................................................................................................... 14
8.4 SMBus compatible 2-wire protocol .................................................................................................................................................... 14
8.4.1 Functional description ................................................................................................................................................................ 14
8.4.2 Differences with the standard SMBus specification (reference [1]) ............................................................................................. 15
8.4.3 Detailed description.................................................................................................................................................................... 15
8.4.4 Bit transfer ................................................................................................................................................................................. 16
8.4.5 Commands ................................................................................................................................................................................ 17
8.4.6 SMBus communication examples .............................................................................................................................................. 17
8.4.7 Timing specification.................................................................................................................................................................... 18
8.4.8 Sleep Mode................................................................................................................................................................................ 19
8.4.9 MLX90614 SMBus specific remarks ........................................................................................................................................... 20
8.5 PWM ................................................................................................................................................................................................. 21
8.5.1 Single PWM format .................................................................................................................................................................... 22
8.5.2 Extended PWM format ............................................................................................................................................................... 23
8.5.3 Customizing the temperature range for PWM output .................................................................................................................. 24
8.6 Switching Between PWM / Thermal relay and SMBus communication .............................................................................................. 26
8.6.1 PWM is enabled ......................................................................................................................................................................... 26
8.6.2 Request condition ...................................................................................................................................................................... 26
8.6.3 PWM is disabled ........................................................................................................................................................................ 26
8.7 Computation of ambient and object temperatures.............................................................................................................................. 27
8.7.1 Ambient temperature Ta ............................................................................................................................................................ 27
8.7.2 Object temperature To ............................................................................................................................................................... 27
8.7.3 Calculation flow .......................................................................................................................................................................... 28
8.8 Thermal relay .................................................................................................................................................................................... 30
9 Unique Features ....................................................................................................................................................................................... 31
10 Performance Graphs .............................................................................................................................................................................. 32
10.1 Temperature accuracy of the MLX90614 ......................................................................................................................................... 32
10.1.1 Standard accuracy ................................................................................................................................................................... 32
10.1.2 Medical accuracy ..................................................................................................................................................................... 33
10.1.3 Temperature reading dependence on V
DD
................................................................................................................................ 33
10.2 Field Of View (FOV) ........................................................................................................................................................................ 35
11 Applications Information.......................................................................................................................................................................... 39
11.1 Use of the MLX90614 thermometer in SMBus configuration ............................................................................................................ 39
11.2 Use of multiple MLX90614s in SMBus configuration ........................................................................................................................ 39
11.3 PWM output operation ..................................................................................................................................................................... 40
11.4 Thermal alert / thermostat................................................................................................................................................................ 40
11.5 High voltage source operation ......................................................................................................................................................... 41
12 Application Comments ............................................................................................................................................................................ 42
13 Standard information regarding manufacturability of Melexis products with different soldering processes ............................................... 44
14 ESD Precautions .................................................................................................................................................................................... 44
15 FAQ ........................................................................................................................................................................................................ 45
16 Package Information ............................................................................................................................................................................... 47
16.1 MLX90614xxA ................................................................................................................................................................................. 47
16.2 MLX90614xCC ................................................................................................................................................................................ 47
16.3 MLX90614xCF ................................................................................................................................................................................ 48
16.4 MLX90614xCH ................................................................................................................................................................................ 48
16.5 MLX90614xCI ................................................................................................................................................................................. 49
16.6 Part marking .................................................................................................................................................................................... 49
16.7 Operating and storage humidity range ............................................................................................................................................. 49
17 Table of figures ....................................................................................................................................................................................... 50
18 References ............................................................................................................................................................................................. 51
19 Disclaimer............................................................................................................................................................................................... 51
3901090614
Rev 009
Page 3 of 52
Data Sheet
June 29, 2015
MLX90614 family
Single and Dual Zone
Infra Red Thermometer in TO-39
4 Glossary of Terms
PTAT
POR
HFO
DSP
FIR
IIR
IR
PWM
DC
FOV
SDA,SCL
Ta
To
ESD
EMC
ASSP
TBD
Proportional To Absolute Temperature
sensor (package temperature)
Power On Reset
High Frequency Oscillator
(RC type)
Digital Signal Processing
Finite Impulse Response.
Digital filter
Infinite Impulse Response.
Digital filter
Infra-Red
Pulse With Modulation
Duty Cycle
(of the PWM) ;
Direct Current
(for settled conditions specifications)
Field Of View
Serial DAta, Serial CLock
– SMBus compatible communication pins
Ambient Temperature
measured from the chip – (the package temperature)
Object Temperature,
‘seen’ from IR sensor
Electro-Static Discharge
Electro-Magnetic Compatibility
Application Specific Standard Product
To Be Defined
Note: sometimes the MLX90614xxx is referred as “the module”.
5 Maximum ratings
Parameter
Supply Voltage, V
DD
(over voltage)
Supply Voltage, V
DD
(operating)
Reverse Voltage
Operating Temperature Range, T
A
Storage Temperature Range, T
S
ESD Sensitivity (AEC Q100 002)
DC current into SCL / Vz (Vz mode)
DC sink current, SDA / PWM pin
DC source current, SDA / PWM pin
DC clamp current, SDA / PWM pin
DC clamp current, SCL pin
MLX90614ESF-Axx
7V
5.5 V
-40…+85°C
-40…+125°C
2kV
2 mA
25 mA
25 mA
25 mA
25 mA
MLX90614ESF-Bxx
MLX90614ESF-Dxx
5V
3.6V
0.4 V
MLX90614KSF-Axx
7V
5.5V
-40…+125°C
-40…+125°C
Table 1: Absolute maximum ratings for MLX90614
Exceeding the absolute maximum ratings may cause permanent damage.
Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
3901090614
Rev 009
Page 4 of 52
Data Sheet
June 29, 2015
MLX90614 family
Single and Dual Zone
Infra Red Thermometer in TO-39
6 Pin definitions and descriptions
4 - VSS
1 - SCL / Vz
3 - VDD
2 - SDA / PWM
Bottom view
Figure 2: Pin description
Pin Name
SCL / Vz
Function
Serial clock input for 2 wire communications protocol. 5.7V zener is available at this
pin for connection of external bipolar transistor to MLX90614Axx to supply the device
from external 8 …16V source.
Digital input / output. In normal mode the measured object temperature is available at
this pin Pulse Width Modulated.
In SMBus compatible mode the pin is automatically configured as open drain NMOS.
External supply voltage.
Ground. The metal can is also connected to this pin.
Table 2: Pin description MLX90614
Note: for +12V (+8…+16V) powered operation refer to the Application information section. For EMC and
isothermal conditions reasons it is highly recommended not to use any electrical connection to the metal can
except by the VSS pin.
With the SCL / Vz and PWM / SDA pins operated in 2-wire interface mode, the input Schmidt trigger function is
automatically enabled.
SDA / PWM
VDD
VSS
3901090614
Rev 009
Page 5 of 52
Data Sheet
June 29, 2015
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