MLX90614 family
Single and Dual Zone
Infra Red Thermometer in TO-39
8.4.3.1.1 Read Word (depending on the command – RAM or EEPROM)
1
7
1
1
8
1
1
7
1
1
S
Slave Address
Wr A
Command
A Sr
Slave Address
Rd A
………..
8
1
8
1
8
1
1
Data Byte Low
A
Data Byte High
A
PEC
A
P
………..
Figure 5: SMBus read word format
8.4.3.1.2 Write Word (depending on the command – RAM or EEPROM)
1
7
1
1
8
1
S
Slave Address
Wr A
Command
A
………..
8
1
8
1
8
1
1
Data Byte Low
A
Data Byte High
A
PEC
A
P
………..
Figure 6: SMBus write word format
8.4.4 AC specification for SMBus
8.4.4.1 Timing
The MLX90614 meets all the timing specifications of the SMBus [1]. The maximum frequency of the
MLX90614 SMBus is 100 KHz and the minimum is 10 KHz.
The specific timings in MLX90614’s SMBus are:
SMBus Request (tREQ ) is the time that the SCL should be forced low in order to switch MLX90614 from PWM
mode to SMBus mode;
Timeout L is the maximum allowed time for SCL to be low. After this time the MLX90614 will reset its
communication block and will be ready for new communication;
Timeout H is the maximum time for which it is allowed for SCL to be high during communication.After this
time MLX90614 will reset its communication block assuming that the bus is idle (according to the SMBus
specification).
Tsuac(SD) is the time after the eighth falling edge of SCL that MLX90614 will force PWM/SDA low to
acknowledge the last received byte.
Thdac(SD) is the time after the ninth falling edge of SCL that MLX90614 will release the PWM/SDA (so the
MD can continue with the communication).
Tsuac(MD) is the time after the eighth falling edge of SCL that MLX90614 will release PWM/SDA (so that the
MD can acknowledge the last received byte).
Thdac(MD) is the time after the ninth falling edge of SCL that MLX90614 will take control of the PWM/SDA
(so it can continue with the next byte to transmit).
3901090614
Rev 003
Page 15 of 40
Data Sheet
03/Oct/2007
MELEXIS [ Melexis Microelectronic Systems ]
