EVB90615 Datasheet, PDF (14/30 Pages) Melexis Microelectronic Systems – Infra Red Thermometer

8.4.5 Bit transfer
Sampling Changing
data
data
SCL
MLX90615
Infra Red Thermometer
PWM/SDA
Figure 9: Bit transfer on SMBus
The data on SDA must be changed when SCL is low (min 300ns after the falling edge of SCL). The data is
fetched by both MD and SDs on the rising edge of the SCL.
8.4.6 Commands
In application mode RAM and EEPROM can be read both with 16x16 sizes. (For example, TOBJ - RAM
address 0x07h will sweep between 0x2D8Ah to 0x4BD0h as the object temperature rises from -40°C to
+115°C). The MSB read from RAM is an error flag (active high) for the linearized temperatures (TOBJ and T_a).
Opcode
Command
0001 aaaa*
EEPROM Access
0010 aaaa*
RAM Access
1100_0110
Enter SLEEP mode
Note*: The aaaa are the 4 LSBits of the memory map address to be read/written.
8.4.7 Sleep Mode
Sleep mode is available in SMBus mode only.
MLX90615 can enter Sleep Mode via command “Enter SLEEP mode” sent via the SMBus interface.
MLX90615 goes back into power-up default mode by forcing the SCL pin low for at least t_DDq= 50 ms. Exit
from Sleep is always in SMBus mode. Valid data will be available typically 0.3 seconds after the device has
woken up.
Note: The previous generation IR thermometer, MLX90614 wakes up through a low pulse on the SDA line,
not SCL.
SCL
t_DDQ
SDA/PWM
Sleep command
Stop
Sleep
Wake-up
Normal operation
Figure 10: Enter and exit Sleep
3901090615
Rev 001
Page 14 of 30
Data Sheet
28/Aug/2008