MLX90614ESF-DAA Melexis Inc, MLX90614ESF-DAA Datasheet - Page 14

• Manufacturer Part Number: MLX90614ESF-DAA
• Description: IC THERMOMETER IR 3V (MED) TO-39
• Manufacturer: Melexis Inc

Specifications of MLX90614ESF-DAA

• Function: Thermometer, Thermostat
• Topology: ADC (Sigma Delta), Voltage Regulator
• Sensor Type: Internal
• Sensing Temperature: -40°C ~ 85°C
• Output Type: PWM, SMBus™
• Output Alarm: No
• Output Fan: No
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Through Hole
• Package / Case: TO-39
• For Use With: EVB90614 - BOARD EVAL FOR MLX90614
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.3.4 RAM
It is not possible to write into the RAM memory. It can only be read and only a limited number of RAM
registers are of interest to the customer.
8.4 SMBus compatible 2-wire protocol
The chip supports a 2 wires serial protocol, build with pins PWM/SDA and SCL.
SMBus communication with MLX90614 is covered in details in application notes, available from
www.melexis.com
8.4.1 Functional description
The SMBus interface is a 2-wire protocol, allowing communication between the Master Device (MD) and one
or more Slave Devices (SD). In the system only one master can be presented at any given time [1]. The
MLX90614 can only be used as a slave device.
Generally, the MD initiates the start of data transfer by selecting a SD through the Slave Address (SA).
The MD has read access to the RAM and EEPROM and write access to 9 EEPROM cells (at addresses
0x20h, 0x21h, 0x22h, 0x23h, 0x24h, 0x25h*, 0x2Eh, 0x2Fh, 0x39h). If the access to the MLX90614 is a read
operation it will respond with 16 data bits and 8 bit PEC only if its own slave address, programmed in internal
EEPROM, is equal to the SA, sent by the master. The SA feature allows connecting up to 127 devices with
only 2 wires, unless the system has some of the specific features described in paragraph 5.2 of reference [1].
In order to provide access to any device or to assign an address to a SD before it is connected to the bus
system, the communication must start with zero SA followed by low RWB bit. When this command is sent
from the MD, the MLX90614 will always respond and will ignore the internal chip code information.
Special care must be taken not to put two MLX90614 devices with the same SD addresses on the
same bus as MLX90614 does not support ARP [1].
The MD can force the MLX90614 into low consumption mode “sleep mode” (3V version only).
Read flags like “EEBUSY” (1 – EEPROM is busy with executing the previous write/erase), “EE_DEAD” (1 –
there is fatal EEPROM error and this chip is not functional**).
3901090614
Rev 006
•
•
SCL – digital input, used as the clock for SMBus compatible communication. This pin has the
auxiliary function for building an external voltage regulator. When the external voltage regulator is
used, the 2-wire protocol is available only if the power supply regulator is overdriven.
PWM/SDA – Digital input/output, used for both the PWM output of the measured object
temperature(s) or the digital input/output for the SMBus. The pin can be programmed in EEPROM to
operate as Push/Pull or open drain NMOS (open drain NMOS is factory default). In SMBus mode
SDA is forced to open drain NMOS I/O, push-pull selection bit defines PWM/Thermal relay operation.
Melexis reserved
…
Melexis reserved
Raw data IR channel 1
Raw data IR channel 2
T
T
T
Melexis reserved
…
Melexis reserved
A
OBJ1
OBJ2
Name
Table 10: Ram addresses
Page 14 of 49
RAM (32x17)
Address
0x000
0x003
0x004
0x005
0x006
0x007
0x008
0x009
0x01F
…
…
Infra Red Thermometer in TO-39
Read access
Yes
Yes
Yes
Yes
Yes
Yes
Yes
…
…
Single and Dual Zone
September 30, 2010
Data Sheet