H3LIS331DL: Consumption during 10Hz Low power mode, and wakeup reactivity ?

[PGoud]

Hello,

Is there any ressource describing the consumption during 10Hz Low-power mode ?

On my side I think I can see little peaks each 100ms then one litle larger peak each 2 seconds.

• Is that the normal behavior ?
• Is it possible to find a typical consumption curve of the sensor during LowPower mode ?
• If the 2 second litle larger peak is a particular processing, could it imply a kind of latency before the awaking of the sensor (passing in normal mode, or generating IT), maybe due to the eventual High pass filter ?

In advance thanks

[Eleon BORLINI]

Hi @PGoud​ ,

I believe it is normal to experience higher current consumption during the operativity of the digital interfaces: for example, during SPI/I2C communication the Vdd / VddIO consumption will be higher (especially on VddIO for I2C) since the dataout is communing High-Low and the current consumption is higher during this phase.

For the Current consumption values in LP mode, you can refer to the datasheet, p. 10. I can say you that that value of 10uA refer to ODR = 1Hz, while the average value at 10Hz is about 75uA.

In particular, I can share with you some bench data on a representative production samples, but not the I supply vs time graph:

 

About the little peak after 2s... do you have enabled some particular event recognition / interrupt triggering every 2 seconds? Otherwise there shouldn't be anomalous peak during (well, there is the possibility to set ODR 0.5Hz, the lowest ODR mode, but it is not your case I see... at least there should not be extra consumption due to the ODR clock tree...).

In case this answer is dealing with your problem (but I'm not fully sure it is), please select is as "best".

-Eleon

[PGoud]

Hello,

I do not find the 75 uA for 10Hz low power mode in the datasheet

I thought it was about 10uA for any of the five low power modes ... sniff ... ;O)

By the way, could you ensure me that setting "0 in ODR",

h3lis331dl_data_rate_set(ptDevCtx, H3LIS331DL_ODR_OFF);

is sufficient to put the sensor in power down mode ?

Indeed, I've got another problem posted on MCU stm32l451 topic, that was refering an excess od 70uA of consumption in STOP2 mode.

But suddenly I imagine that my H3LIS331DL could no be correctly set in "power done mode", could you tel me the exact parameters that ensure power down mode ?

[Eleon BORLINI]

Hi @PGoud​ ,

the H3LIS331DL starts in Power down mode: I mean, after the device power on, if you don't configure any registers (leaving them to their default value) PD is the boot default, as stated in the datasheet p.24. If you however are running the acquisition and you want to set the device in PD without powering it off, you have to set the both the ODR bits (DR1, DR0) and the PM bits (PM2 - PM0) of the CTRL_REG1 (20h) register to 0.

The estimated current consumption in PD mode should be about 1uA (actually, less than 0.2uA on average), coherently with the datasheet.

-Eleon

[PGoud]

Hello,

Still struggling with my 70 uA to high consumption.

As an exemple here are my board consumption with H3LIS331DL in "Power down" mode and in "Low power mode 10Hz/100Hz".

As I told you befaore you can sees the peaks of about 300uA/20ms each 2s. I suppose this could be the working consumtion in LowPower mode. Could you confirme me that .

But My problem remain with the 70 uA FEET of consumtion, notice I could also measure abou70 uA directly on the VCC of H3LIS331DL in any of these modes ...

I tried using INT1 in "open drain" with pull up on MCU side, and in PushPull without any pull on MCU side. In both cases I use "Active low" modes.

Please any idea is welcome

[Eleon BORLINI]

Hi @PGoud​ ,

if you are facing 70uA consumption when in POWER DOWN mode (i.e. for example just after the device is powered on), and you are measuring the consumption on Vdd pin with just the H3LIS331DL device on it, there might be something wrong in the hardware connections...

Could you please share your schematic, or check it with the datasheet application suggestions (p. 16) or the adapter example?

-Eleon

[PGoud]

Hello,

I'll make more tests this afternoon.

However here is our schematic of Accelero's part.

[Eleon BORLINI]

Schematic looks ok... Which is the Vdd/VddIO value?

-Eleon

[PGoud]

Hey !!

I did not take care of this but I was SDO set to 0 to choose and adress different from LIS2DE seems to be my over consumption problem !

Please could you confirm me that the electronic behind SDO could generate this consumption.

That's really sad for us if this is the case and if the LIS2DE has got the same problem, because we planed to use both circuit simultaneously in some cases ...

[Eleon BORLINI]

Are you meaning the LIS2DE or the LIS2DE12 device? In this second case yes, you can face an overcurrent consumption if you (as described in the datasheet p. 9).

Please note however that in order to disable the internal pull-up on the SDO/SA0 pin, you have to write 90h in CTRL_REG0 (1Eh).

But not for the other devices.

-Eleon

[PGoud]

At the moment I just use the H3LIS331DL.

And my problem was finally the "internal pull-up on SDO" that drain about 70uA.

Looking at the datasheet this pull-up does not seem desactivable . Please confirm me.

But in a future we may use LISDE12TR and eventually in conjunction with H3LIS331DL... so in that case the "Desactivable pull-up" on LIS2DETR will be the solution. OK.

So, if you want the topic can now be closed.

Thanks for these exchanges.

[Eleon BORLINI]

Hi @PGoud​ ,

you're welcome.

>> Looking at the datasheet this pull-up does not seem de-activable. Please confirm me.

You are right, the pull-up is not de-activable from the standard configuration register. As an alternative, you could try with the 90h in CTRL_REG0 (1Eh) for the H3LIS331DL too, but this is a reserved register and should not be modified... a power off-on of the device will restore the factory calibration data.

-Eleon