Data Sheet

MLX90614 family
Single and Dual Zone
Infra Red Thermometer in TO-39
8.4.6 Commands
RAM and EEPROM can be read both with 32x16 sizes. If the RAM is read, the data are divided by two, due
to a sign bit in RAM (for example,
T
OBJ1
- RAM address 0x07h will sweep between 0x27ADh to 0x7FFF as the
object temperature rises from -70.01°C to +382.19°C). The MSB read from RAM is an error flag (active high)
for the linearized temperatures (T
OBJ1
, T
OBJ2
and T
a
). The MSB for the raw data (e.g. IR sensor1 data) is a sign
bit (sign and magnitude format). A write of 0x0000 must be done prior to writing in EEPROM in order to erase
the EEPROM cell content. Refer to EEPROM detailed description for factory calibration EEPROM locations
that need to be kept unaltered.
Opcode Command
000x xxxx* RAM Access
001x xxxx* EEPROM Access
1111_0000** Read Flags
1111_1111 Enter SLEEP mode
Note*: The xxxxx represent the 5 LSBits of the memory map address to be read/written.
Note**: Behaves like read command. The MLX90614 returns PEC after 16 bits data of which only 4 are
meaningful and if the MD wants it, it can stop the communication after the first byte. The difference between
read and read flags is that the latter does not have a repeated start bit.
Flags read are:
Data[7] - EEBUSY - the previous write/erase EEPROM access is still in progress. High active.
Data[6] - Unused
Data[5] - EE_DEAD - EEPROM double error has occurred. High active.
Data[4] - INIT - POR initialization routine is still ongoing. Low active.
Data[3] - Not implemented.
Data[2..0] and Data[8..15] - All zeros.
Flags read is a diagnostic feature. The MLX90614 can be used regardless of these flags.
For details and examples for SMBus communication with the MLX90614 check the www.melexis.com
8.4.7 Sleep Mode
The MLX90614 can enter in Sleep Mode via the command “Enter SLEEP mode” sent via the SMBus
interface. This mode is not available for the 5V supply version. To limit the current consumption to 2.5uA
(typical), the SCL pin should be kept low during sleep. MLX90614 goes back into power-up default mode (via
POR reset) by setting SCL pin high and then PWM/SDA pin low for at least t
DDq
=80ms. If EEPROM is
configured for PWM (EN_PWM is high), the PWM interface will be selected after awakening and if
PWM control [2], PPODB is 1 the MLX90614 will output a PWM pulse train with push-pull output.
8.4.7.1 Enter Sleep Mode
Sleep
command
Stop
condition
Stop
Sleep
SCL
PWM/SDA
Figure 9: Enter sleep
3901090614 Page 18 of 42 Data Sheet
Rev 004 30/Jul2008