Melexis MLX90601 Technical data
查询MLX90601 供应商查询MLX90601 供应商
Features and Benefits
• Remote temperature measurement
• Fully linearized signals
• Analog voltage output, digital PWM output and SPI interface
• Factory calibrated
• Rigid PCB with automotive protection circuitry, or flex circuit board.
• EEPROM ECC
• Open drain relay driver output
Applications
• Automotive climate control
• Toasters, microwave ovens and other applications that require temperature control
• Residential, commercial climate control and occupancy detection
• Industrial temperature transducer and monitoring applications
MLX90601 family
IR thermometer modules
Ordering Information
Suffix
Part No Ta Package Type Description PCB
MLX90601 E ZA BAA 8 bit Analog To –20C /120C, Ta 0C..50C Rigid
MLX90601 E ZA DAA PWM, To –20C /120C, Ta 0C..50C Rigid
MLX90601 E ZA CAA Digital SPI/PWM To –20C/120C, Ta 0C..50C, 5V supply Rigid
MLX90601 K ZA BKA 8 bit Analog To –20C /120C, Ta –20C..85C, 5V supply Flex
MLX90601 K ZA CKA Digital SPI/PWM To –20C/120C, Ta -20C..85C, 5V supply Flex
Notes: Ta ambient operating temperature range
MLX90601EZA-XXX: -40C / +85C
MLX90601KZA-XXX: -40C / +125C
1 Functional Diagrams
MLX90247
Rsens
VSS
VDD
C3
TEMPOUT
IROUT
CS
SCLK
SDI
SDO
REL1 REL
VREFP VREF
MLX90247
Rsens
VSS
IR+
IRINP
IR-
IRINN
TINP
TINN
MLX90313
CREF VSS
R3
IR+
IR-
IRINP
IRINN
TINP
TINN
MLX90313
CREF VSS
R3
VDD
IROUT
TEMPOUT
REL1
R1D
R1C
5V
C3
IROUT
C6
TEMPOUT
C7
REL1
VSS/GND
5V
TEMPOUT
IROUT
CS
SCLK
DIN
DOUT
VSS/GND
MLX90601 EZA-BAA MLX90601 EZA-CAA
MLX90601 EZA-DAA MLX90601 KZA-BKA
MLX90601 KZA-CKA
3901090601 Page 1 of 49 Aug/02
Rev. 007
2 Description
The MLX90601 Family modules are versatile IR
thermometer modules, which perform signal
conditioning, linearisation and ambient
temperature compensation. The modules are
built around the MLX90313 IR sensor interface,
which uses high performance chopper stabilized
amplifiers, providing excellent noise
performance. The sensing element is the
MLX90247 discrete IR thermopile sensor.
The modules are delivered factory calibrated.
The output signals can be analog voltage
outputs; PWM coded digital outputs, or a bidirectional SPI compatible serial interface. All
output signals are linear with the applied
temperature.
All modules feature the open drain relay driver
output available in MLX90313.
Several types of modules are available. First
types are the modules for automotive
applications, which have additional ESD
protection circuitry on board. These modules can
MLX90601 family
IR thermometer modules
have an analog voltage output (MLX90601EZABAA), or a digital PWM coded output
(MLX90601EZA-DAA). The substrate is in this
case a FR4 PCB with a 5 pin through-hole
connector.
Alternatively there are some modules targeted
for industrial or consumer applications. These
modules can have also analog outputs
(MLX90601KZA-BKA) or PWM outputs
(MLX90601KZA-CKA and MLX90601EZA-CAA).
All three modules have a SPI interface available
for full programmability.
The MLX90601KZA-BKA and MLX90601KZACKA are built on a flexible polyamide substrate,
making building in the sensor very easy.
The user can choose now the most suited
module depending on electrical and mechanical
needs.
3901090601 Page 2 of 49 Aug/02
Rev. 007
MLX90601 family
IR thermometer modules
CONTENTS
1 FUNCTIONAL DIAGRAMS ..............................................................................................................1
2 DESCRIPTION................................................................................................................................. 2
3 GLOSSARY OF TERMS ..................................................................................................................5
4 ABSOLUTE MAXIMUM RATINGS...................................................................................................6
5 MLX90601 ELECTRICAL SPECIFICATIONS...................................................................................6
6 GENERAL DESCRIPTION............................................................................................................... 8
6.1 T
6.2 S
6.3 A
7 MLX90601EZA-BAA ...................................................................................................................... 10
7.1 K
7.2 G
7.3 P
7.4 PIN-
7.5 E
7.6 C
7.7 A
8 MLX90601EZA-DAA ...................................................................................................................... 15
8.1 K
8.2 G
8.3 P
8.4 PIN-
8.5 E
8.6 C
8.7 A
9 MLX90601EZA-CAA ...................................................................................................................... 21
9.1 K
9.2 G
9.3 S
9.4 P
9.5 PIN-
9.6 E
9.7 C
9.8 A
10 MLX90601KZA-BKA...................................................................................................................... 30
10.1 K
10.2 G
10.3 S
10.4 P
10.5 PIN-
10.6 E
10.7 C
3901090601 Page 3 of 49 Aug/02
Rev. 007
HEORY OF OPERATION
ENSOR CHARACTERISTICS
CCURACY
EY PROPERTIES
ENERAL DESCRIPTION
HYSICAL OUTLINE
LECTRICAL SPECIFICATIONS
ALIBRATION DETAILS
PPLICATIONS INFORMATION
EY PROPERTIES
ENERAL DESCRIPTION
HYSICAL OUTLINE
LECTRICAL SPECIFICATIONS
ALIBRATION DETAILS
PPLICATIONS INFORMATION
EY PROPERTIES
ENERAL DESCRIPTION
ERIAL PERIPHERAL INTERFACE
HYSICAL OUTLINE
LECTRICAL SPECIFICATIONS
ALIBRATION DETAILS
PPLICATIONS INFORMATION
EY PROPERTIES
ENERAL DESCRIPTION
ERIAL PERIPHERAL INTERFACE
HYSICAL OUTLINE
LECTRICAL SPECIFICATIONS
ALIBRATION DETAILS
.................................................................................................................................. 8
OUT AND PIN DESCRIPTIONS
OUT AND PIN DESCRIPTIONS
OUT AND PIN DESCRIPTIONS
OUT AND PIN DESCRIPTIONS
................................................................................................................ 8
...........................................................................................................8
....................................................................................................................... 10
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.................................................................................................. 12
.................................................................................................. 18
(SPI)......................................................................................... 23
.................................................................................................. 26
(SPI)......................................................................................... 32
.................................................................................................. 35
MLX90601 family
IR thermometer modules
10.8 A
11 MLX90601KZA-CKA...................................................................................................................... 38
11.1 K
11.2 G
11.3 S
11.4 P
11.5 PIN-
11.6 E
11.7 C
11.8 A
12 ESD PRECAUTIONS...................................................................................................................... 46
PPLICATIONS INFORMATION
EY PROPERTIES
ENERAL DESCRIPTION
ERIAL PERIPHERAL INTERFACE
HYSICAL OUTLINE
OUT AND PIN DESCRIPTIONS
LECTRICAL SPECIFICATIONS
ALIBRATION DETAILS
PPLICATIONS INFORMATION
....................................................................................................................... 38
..................................................................................................................... 43
....................................................................................................... 37
.............................................................................................................. 38
...................................................................................................... 44
................................................................................................................. 45
....................................................................................................... 45
(SPI)......................................................................................... 40
.................................................................................................. 43
13 RELIABILITY INFORMATION........................................................................................................ 46
14 FAQ................................................................................................................................................ 46
15 APPENDIX A: SPI INTERFACING TO AUTOMOTIVE MODULES................................................. 48
15.1 C
15.2 SPI C
OMPONENT REFERENCES
OMMUNICATION CABLE PIN-OUT
.......................................................................................................... 48
........................................................................................... 48
3901090601 Page 4 of 49 Aug/02
Rev. 007
3 Glossary of Terms
ADC: Analog to Digital Converter
Ambient Compensation: The IR signal
captured by a thermopile sensor is not only
dependent on the temperature of the object
(Tobject) but also on the temperature of the
sensor itself. Therefore the IR signal is
compensated for this effect by means of the
measured sensor temperature (Tambient). This
rather complex calculation is performed in the
linearisation unit of MLX90313.
Chopper Amplifier: Special amplifier
configuration aimed at ultra low offset.
DAC: Digital to Analog Converter.
EEPROM: Non-volatile memory that can be
electrically erased and rewritten. This type of
memory is used to store configuration and
calibration data for the module.
ECC: Error Checking and Correction. The
EEPROM on board of MLX90313 is equipped
with a checking and correction feature based on
the Hamming Code method.
IR: Infrared. Every object emits infrared
radiation in relation to its temperature. This
effect can be used to measure this temperature
without the need for physical contact.
Linearisation: The signal from a thermopile is
not linear with the object temperature.
MLX90313 is therefore equipped with a digital
calculation unit that produces an output that is
linear with the object temperature.
POR: Power-on reset: Reset circuit that starts
the digital system in a known state whenever the
supply voltage is cycled
PSSR: Power Supply Rejection Ratio: Measure
for an amplifier’s immunity to disturbances on
the supply connections.
PTC: See Thermistor
Ta, Tambient: The temperature of the IR
sensor.
Target: or Object: The object the IR module is
aimed at.
MLX90601 family
IR thermometer modules
Thermistor: Temperature dependant resistor.
Basically there are 2 types. The types that
increase their resistance with rising temperature
are PTC (positive thermal coefficient) type. The
ones that decrease their resistance with rising
temperature we call NTC (negative thermal
coefficient) type. The MLX90313 can work with
both types. The MLX90601 modules are
equipped with sensors that use PTCs.
To, Tobject: The temperature of the object one
wishes to measure with the module
3901090601 Page 5 of 49 Aug/02
Rev. 007
MLX90601 family
IR thermometer modules
4 Absolute Maximum Ratings
Automotive Grade modules
MLX90601EZA-BAA – MLX90601EZA-DAA
Voltage, VDD (over-voltage) 80V
Supply Voltage, VDD (operating) 5.5V
Supply Current, IDD 6mA
Operating Temperature Range, TA
ESD Sensitivity (AEC Q100 002) 4kV
PCB SPI module
MLX90601EZA-CAA
Voltage, VDD (over-voltage) 7V
Supply Voltage, VDD (operating) 5.5V
Supply Current, IDD 6mA
Operating Temperature Range, TA
ESD Sensitivity (AEC Q100 002) 1kV
Exceeding the absolute maximum ratings may cause permanent damage. Exposure to absolutemaximum rated conditions for extended periods may affect device reliability.
-40°C / 105°C
-40°C / 105°C
Flexible modules
MLX90601KZA-CKA – MLX90601KZA-BKA
Voltage, VDD (over-voltage) 7V
Supply Voltage, VDD (operating) 5.5V
Supply Current, IDD 6mA
Operating Temperature Range, TA
ESD Sensitivity (AEC Q100 002) 1kV
-40°C / 125°C
5 MLX90601 Electrical Specifications
DC Operating Parameters TA = -40oC to 125oC, VDD = 4.75V to 5.25V (unless otherwise specified)
Parameter Symbol Test Condition Min Typ Max Unit
Regulator and consumption
POR threshold voltage Vpor 1.1 1.3 1.5 V
IR-chain amplifier and output driver
Power supply rejection
ratio
Input referred white noise Vnir rms-value 25
Chopper frequency fc 8 kHz
Output voltage range IROUT 0 Vdd-0.2 V
Output source current Iod IROUT 1 mA
Output sink current Ios IROUT 20 uA
DC Output impedance,
drive
DC Output impedance,
sink
Amplifier bandwidth BW 500 Hz
Temp-chain amplifier and output driver
Power supply rejection
ratio
Input referred white noise Vntemp rms-value 400
Chopper frequency fc 15 kHz
Output voltage range ORtemp TEMPOUT 0 Vdd-0.2 V
Output source current Iod TEMPOUT 1 mA
Output sink current Ios TEMPOUT 20 uA
PSSR
rod IROUT 10
ros IROUT 100
PSSR
f ≤ 100kHz
f ≤ 100kHz
75 dB
75 dB
nV/√Hz
Ω
Ω
nV/√Hz
3901090601 Page 6 of 49 Aug/02
Rev. 007
MLX90601 family
IR thermometer modules
5 MLX90601 Electrical Specifications
DC Operating Parameters TA = -40oC to 125oC, VDD = 4.75V to 5.25V (unless otherwise specified)
Parameter Symbol Test Condition Min Typ Max Unit
AC Output impedance ro TEMPOUT 100
Amplifier bandwidth BW 500 Hz
Rel1 open drain relay driver
High voltage protections 32 V
output impedance Ro 10
ADC
Monotonic guaranteed by design
Differential non-linearity DNL 0.4 LSB
Integral non-linearity INL ½ LSB
Gain error full scale 1 LSB
Total input-referred noise Vref=3V 0.2 LSB
DAC
Resolution 8 bit
Monotonic guaranteed by design
Differential non-linearity DNL ½ LSB
Integral non-linearity INL ½ LSB
PWM
PWM Clock period Tclk 45 50 55
PWM Total period T 92.16 102.4 112.64 ms
Leading buffer time t1 % of T 12.5
Trailing buffer time t5 % of T 12.5
Duty cycle high t2 % of T 0 50 %
Duty cycle low t3 % of T 0 50 %
Error signal t4 % of T 25
Rise time* 10% to 90% of Vh 13.3 100
Fall time* 90% to 10% of Vh 13.3 100
Output voltage high Vh Ihigh=2mA 4 V
Output voltage low Vl Ilow=2mA 1 V
*Without external loading
Ω
Ω
µs
%
%
%
µs
µs
3901090601 Page 7 of 49 Aug/02
Rev. 007
MLX90601 family
IR thermometer modules
6 General Description
6.1 Theory of operation
The MLX90601 modules are developed especially to make IR temperature sensing easy. All modules
have a linearised output signal. Also they are factory calibrated, so making all modules interchangeable.
Also this relieves customers from complex calibration procedures.
All modules have a MLX90247 thermopile sensor as IR sensing element. The output of this sensor is a
function of both Object (IR) and ambient temperature. Ideally the output voltage of the thermopile sensor
is:
α
Where To is Object temperature in Kelvin, and Ta is the ambient temperature in Kelvin. Alpha is a device
constant. It is clear from above equation that the ambient temperature must be known before the object
temperature can be calculated. Therefore the MLX90247 thermopile sensor has a thermistor built-in.
Melexis has designed a powerful ASIC to perform the signal processing of the thermopile output voltage.
MLX90313 amplifies the signals coming from MLX90247 and converts them to digital by means of two
high performance, low noise, chopper stabilized amplifiers and the 12-bit analog to digital converter. The
digital unit on the interface then performs the ambient compensation of the IR signal. This results in two
temperature signals, one representing the temperature of the object the IR sensor is pointed at (Tobject)
and one representing the temperature of the sensor (Tambient). Both signals are then linearised and
presented at the outputs in analog of PWM coded form. When using modules that have also SPI, the
temperature registers can be read directly through the serial interface.
The linearisation unit can only operate when both Ta (ambient temperature) and To (object temperature)
are both in a distinct calibrated range. This has an important implication for the ambient temperature.
When the modules are used outside the calibrated ambient temperature, the object temperature is
calculated using a false ambient temperature, resulting in an erroneous output signal. If the ambient
temperature is below the ambient calibration range, the OVL flag in the SPI register is set and the
temperature data bits are all zero. For analog output modules, the output will be zero volts. Alternatively, if
the ambient temperature is above the ambient calibration range, the OVH flag in the SPI register is set
and the temperature data bits are all one. For analog output modules, the output will be 4.5 volts.
When returning into calibrated ambient temperature range, the module will resume normal operation.
Our standard products have such ranges that they can suit a maximum number of applications. Currently
there are four different versions of modules offered.
44
)(
TaToVir −=
6.2 Sensor characteristics
All modules have the same thermopile sensor. For detailed specification we refer to the datasheet on
MLX90247, available from the Melexis web site. In a calibrated module the linearisation unit of MLX90313
takes all characteristics of the sensor into account, including all process variations they are subject to.
The TO-39 sensor housing of the thermopile has a 2.5mm diameter aperture, resulting in a 70° full angle
field of view, for 90% % of the IR energy. The silicon filter used as IR-window is treated with an
antireflective coating that will pass minimum 75% of IR radiation in the wave length band from 7.5µm to
13.5µm.. Below 5µm, 99.5% of incoming radiation is reflected by the filter. This makes the sensor
insensitive to visible light.
6.3 Accuracy
Accuracy of the module depends mainly on calibration precision. For absolute accuracy please refer to
calibration details for the appropriate module. The error of the output depends on both object and ambient
temperature. Repeatability and stability are very good, the error is < 0.4C, but both ambient and object
3901090601 Page 8 of 49 Aug/02
Rev. 007
MLX90601 family
IR thermometer modules
temperature must be kept stable. For making relative measurements care must be observed. The
MLX90313 uses a piecewise modified quadratic approximation method, and on the reference points, the
output can change with several tenths of degrees. Of course, the absolute accuracy will always be within
specification.
3901090601 Page 9 of 49 Aug/02
Rev. 007
MLX90601 family
5.4
IR thermometer modules
7 MLX90601EZA-BAA
7.1 Key properties
• Automotive use
• analog output signals with 8 bit resolution
• relay comparator
• only 5 connections
7.2 General description
The MLX90601EZA-BAA is a module that is targeted for automotive use. In addition to the small amount
of components like the sensor, ASIC etc there are also 2 RC protection circuits on the IROUT and
TEMPOUT pins. This allows the module to be used in automotive environments.
The Object temperature information is available at the IROUT pin. The ambient temperature information is
available on the TEMPOUT pin. The resolution of the output D/A converter is 8bit. The output drivers
have a maximum output voltage of 4.5V when the maximum calibrated temperature is reached.
If the ambient temperature is out of the calibrated temperature range, the correct object temperature
cannot be calculated. For applications where the ambient temperature can rise above the maximum
calibrated temperature, the ambient temperature output must be monitored to make sure the object
temperature is valid.
Next to the temperature outputs there is also a relay driver output. The relay driver has a threshold that is
pre-set to 50 °C, with a hysteresis of 5 °C. Note that this module has no SPI interface connector available.
If the user wants to reconfigure this type of module, this can be done with the EVB board and a special
test clip. Refer to appendix A for details.
The relation of the output voltage to the temperature is defined as follows:
Vout
T +−= *
( )
TminTminTmax
where:
T measured temperature
Vout analog output voltage on IROUT or TEMPOUT pins.
Tmin minimal calibrated temperature
Tmax maximum calibrated temperature
Refer to calibration details for calibrated ranges info
3901090601 Page 10 of 49 Aug/02
Rev. 007
MLX90601 family
IR thermometer modules
A graphical representation is depicted below.
IROUT output voltage
versus
Object Temperature
4.5
4
3.5
3
2.5
2
1.5
Output Voltage IROUT (V)
1
0.5
0
-40 110 1201008060200-20
40
Object Temperature To (degC)
The behavior of the module outside the calibrated ranges is shown below:
TEMPOUT output voltage
Output Voltage TEMPOUT (V)
versus
Ambient Temperature
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
Ambient Temperature Ta (degC)
500
T object in
range
T ambient in
range
I I
II I
I or II II
I or II III
-20C
III II
120C
III II IIIIII
50C0C-40C 105C
Tobject
Tambient
Module operating conditions
Effect on outputs
Object temperature output is working normal
Ambient temperature output is working normal
Object temperature output will be clamped 0V (To < -20C) or clamped at 4.5V (T0>120C).
Ambient temperature output is working normal
BOTH temperature outputs will be clamped 0V (Ta < 0C) or clamped at 4.5V (Ta>50C).
The module may be damaged if operated outside the ambient temperature range.
BOTH temperature outputs will be clamped 0V (Ta < 0C) or clamped at 4.5V (Ta>50C).
3901090601 Page 11 of 49 Aug/02
Rev. 007
7.3 Physical outline
MLX90601 family
IR thermometer modules
7.4 Pin-out and pin descriptions
pin-out information
pin name function
1 IROUT analog output infrared temperature
2 TEMPOUT analog output ambient temperature
3 VDD Supply voltage
4 REL1 Relay output
5 VSS Ground connection
IROUT IRout analog voltage output pin. The voltage at this pin is a linear representation of Tobject,
the temperature of the object the IR sensor is pointed at.
TEMPOUT Ambient temperature analog voltage output pin. The voltage at this pin is a linear
representation of Tambient, the temperature of the IR sensor, as measured by the PTC
inside MLX90247.
VDD Supply pin
REL1 Open drain relay driver output. The typical on-resistance of this driver is <10 Ohms.
REL1
Tobject
COMP
Threshold in
EEPROM
VSS
Hysteresis
in EEPROM
3901090601 Page 12 of 49 Aug/02
Rev. 007
MLX90601 family
IR thermometer modules
The comparator is a digital comparator, with a resolution of 12 bits. By default the input
polarity is inverting. Threshold and hysteresis values are version dependent. These
settings can be changed by factory programming on request. Refer to calibration settings
for factory preset values.
VSS Supply pin (0V)
7.5 Electrical specifications
Parameter symbol condition min typ max unit
Supply Voltage
Supply voltage range VDD 4.75 5 6 V
Power consumption IDD Ta=25C 5 5.6 mA
analog outputs IROUT/TEMPOUT
D/A converter resolution 8 Bits
Output source current Iod 1 mA
Output sink current Ios 20 uA
AC Output impedance ro 100
Capacitive load Cmax 100 nF
Rel1 open drain relay driver
output impedance Ro 10 Ohms
High voltage protections 32 V
Ω
7.6 Calibration details
Maximum calibrated object temperature 120°C
Minimum calibrated object temperature -20°C
Object temperature Accuracy ±2°C
Maximum calibrated ambient temperature 50°C
Minimum calibrated ambient temperature 0°C
Ambient temperature Accuracy ±1°C
Response time 500ms
REL1 source Tobject
REL1 polarity (*) Inverting
REL1 threshold 50°C
REL1 hysteresis 5°C
Emissivity 0.99
Note: Comparator polarity:
Inverting: relay switches OFF if temperature is above the threshold.
Non-inverting: relay switches ON if temperature is above the threshold.
3901090601 Page 13 of 49 Aug/02
Rev. 007
MLX90601 family
IR thermometer modules
7.7 Applications information
Connection of the MLX90601 module into an application is straightforward. The 5V regulated supply
should be connected between pin 3 (VDD) and pin 5 (VSS).
The outputs can be measured relative to VSS at pin 1 (IROUT) for Tobject and pin 2 (TEMPOUT) for
Tambient, e.g. by means of a voltmeter. In an actual application the module outputs can be directly
connected to the A/D inputs of a microcontroller, e.g. as a replacement for a conventional temperature
sensor.
In many applications, the ambient temperature of the sensor is not needed. In this case, pin 2 can simply
be left open.
The REL1 signal at pin 4 can be used as input for a digital I/O or to drive a relay (not shown). In case of a
digital input the microcontroller must have internal pull-up resistors or an external pull-up resistor must be
added.
IR sensor
Thermisto
MLX90247
IR+
IR-
r
Rsens
VSS
IRINP
IRINN
TINP
TINN
OPA
OPA
A/D
Digital
A/D
D/A
D/A
Ta
MLX90313
Ta
To
COMP12
TEMPOUT
IROUT
REL1
2
1
4
Application
Microcontroller
A/D input (optional)
A/D input
Digital input
MLX90601B
EEprom, Control and Support Blocks
VSS
VDDCREF
3
5V
5
VSS
3901090601 Page 14 of 49 Aug/02
Rev. 007
MLX90601 family
8
8
8
16
16
IR thermometer modules
8 MLX90601EZA-DAA
8.1 Key properties
• Automotive use
• PWM coded output signals with 10 bit resolution
• ambient temperature underflow and overflow flagging
• relay comparator
• only 5 connections
8.2 General description
The MLX90601EZA-DAA is a module that is targeted for automotive use. In addition to the small amount
of components like the sensor, ASIC etc there are also 2 RC protection circuits on the IROUT and
TEMPOUT pins. This allows the module to be used in automotive environments.
The Object temperature information is available at the IROUT pin. The ambient temperature information is
available on the TEMPOUT pin. The resolution of the Pulse Width Modulated output is 10 bits. Next to
the temperature information, these outputs can also flag ambient temperature underflow and overflow.
The module has an on-board ECC (EEPROM consistency check), that checks the stored calibration
constants and settings. In case of failure, the output fill flag this condition.
If the ambient temperature is out of the calibrated temperature range, both PWM signals will flag this
condition, and the object and ambient temperatures will not be available until the ambient temperature is
back in the calibrated temperature range.
Next to the temperature outputs there is also a relay driver output. The relay driver has a threshold that is
pre-set to 50 °C, with a hysteresis of 5 °C. Note that this module has no SPI interface connector available.
If the user wants to reconfigure this type of module, this can be done with the EVB board and a special
test clip. Refer to appendix A for details.
The PWM coding format is depicted below
t4:Error Signaling Band
Valid Data Output Band
FE
OVH
output signal
t
1
1
T
The PWM signal has a period of 102.4ms typical consisting of 2048 clock cycles of 50µs. Every frame
starts with a leading buffer time, t1, during which the signal is always high, as shown in the figure. The
leading buffer time is followed by a slot for the useful data signal starting at 1/8T ending at 5/8T, where the
ratio t2/(t2+t3) is the representation of the output value. t4 is a slot for signaling of special conditions,
such as out of range measurement of the sensor temperature, Tambient and the occurrence of a fatal
EEPROM error, i.e. an error that can no longer be corrected automatically by the ECC circuitry of
MLX90313.
3901090601 Page 15 of 49 Aug/02
Rev. 007
t
2
t
3
5
OVL
t
5
time
T
T
T
16
12
11
13
7
T
T
T0
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