MLX90621

16x4 IR array

Datasheet

39001090621

Page 30 of 44

Datasheet IR16x4

Rev 3.0

15 September 2016

Device modes

9.3.

The device can operate in following modes:

•

Normal mode

•

Step mode

•

Power saving mode

Normal mode

9.3.1.

In this mode the measurements are constantly running. Depending on the selected frame rate Fps in the

configuration register, the data for IR pixels and Ta will be updated in the RAM each 1/Fps seconds. In this mode the

external microcontroller has full access to the internal registers and memories of the device (both for 90670 and the

EEPROM chip).

Step mode

9.3.2.

This mode is foreseen for single measurements triggered by an external device (microcontroller). Entering this mode

is possible by writing the appropriate code in the configuration register. A measurement is triggered by sending the

command StartMeas (see 9.4.1). On detecting the command, the Mlx90621 will start the measurements

immediately after the I

The measurement time is

While the Step mode measurement is ongoing all ‘start new measurement in step mode’ commands will be

acknowledged but not executed. All other valid commands are executed accordingly.

A flag bit in Configuration register (bit 0x09) is dedicated in order to be able to check whenever the measurement is

done.

Figure 21 Write configuration register (SA = 0x60, command LSByte = 0x01 command MSByte = 0x08)

Power saving mode

9.3.3.

In this mode the device will be completely shut down and the current consumption will be minimized to less than

6µA. Entering this mode is initiated by writing ‘1’ in the configuration register bit 7. Upon receiving it the device will

shut down all electronics, including the internal oscillator. The chip will monitor the I

will wake up the oscillator and the chip will receive and evaluate the slave address. If the address is 0x60 (address

programmed in Mlx90621) the device will evaluate the whole command and will execute it. If not, the oscillator will

be switched off again.

SCL

SDA

1

0

1

0

0

0

0

A

0

0

0 0

0 0

1 A

S

A

P

0

Slave address

Command

0

0

0

0 1

0 0

0

Start Meas

W