LIS3DH Power-Down Mode

[Vagni]

On my custom board LIS3DH is supplied with Vdd = Vdd_IO = 3.3 V and is driven through I2C digital interface.

On power-on LIS3DH, after its boot sequence (5 ms) should be automatically configured in power-down mode with a current consumption less then 1 uA. But on my custom board, with no I2C driver action, I measure IddPdn = 310 uA after power-on.

If I set power-down mode (i.e. ODR = 0, LPen = 0) through I2C driver, then I measure IddPdn = 150 uA.

If a set the operative ODR and FS, I properly read the acceleration data.

In some conditions I need to disable the sensor to minimize the current consumption of my system.

So, what is the correct sequence to make LIS3DH enter in power-down mode?

[Miroslav BATEK]

Can you please share your schematics?

[Vagni]

I attached my schematic.

You can see there are pullups on INT1 and INT2 outputs, so I need to initialize INT1 and INT2 active polarity as LOW, in order not to have current consumption on the pullups .

Thank you.

[Vagni]

SOLVED!

The SDO/SA0 pin of LIS3DH has an internal pullup (typ. 20.4K @ 3.3V): this was the cause of the current comsumption.

Fortunately, I can disconnect the internal SDO/SA0 pullup writing SDO_PU_DISC bit in the CTRL_REG0 register.