LIS2DE12 supply 1,8v / 3,3v

[GLE B.1]

Hello,

I have an issue with my LIS2DE12, when i'm starting up my board i'm doing the configuration of the device and then i need to put the boad from 1,8V to 3,3V to communicate with an other component. BUT when I come back to 1,8V the LIS2DE12 have take back his default configuration... (REG0 = 16 ; REG1 = 7 ; OTHER = 0)

Do you have ever seen this ?

I have been looking with an oscilloscope the power supply and it never fall under 1,8V and never go more than 3,3v. (1,71v to 3,6v in the doc so looks good)

Thanks,

Regards,

Goulwen LE BOZEC.

[Eleon BORLINI]

Hi Goulwen @GLE B.1​ ,

the device should maintain the previous configurations if not powered off...

Are you changing both Vdd and VddIO in your procedure? And how fast is your voltage ramp (no limits on the supply, I believe)?

And have you mounted the 10uF / 100nF decoupling capacitors -STEVAL-MKI175V1 as example- on Vdd ( VddIO lines on your application board, to mitigate the voltage slope?

-Eleon

[GLE B.1]

Hi @Eleon BORLINI​ ,

Yeah both are link together. 1,8v -> 3,3v : around 1ms

3,3v -> 1,8v : around 10ms

Regards,

Goulwen LE BOZEC.

[Eleon BORLINI]

Hi @GLE B.1​ ,

schematic looks good, the only component missing if compared with the STEVAL-MKI175V1 reference schematic is the 100nF decoupling capacitor on the VddIO line, but it should not be the cause of your issue

Also the supply voltage ramps are good... are you facing the "reset" behavior on a single device or also on other parts, if you have the possibility to test them?

-Eleon

[GLE B.1]

Hello @Eleon BORLINI​  !

I'm facing the same issue on two differents boards. I will try on more maybe tomorrow.

But I guess it will be the same..

Regards,

Goulwen LE BOZEC.

[GLE B.1]

Hello @Eleon BORLINI​  !

I tried a new card. On this one we have a bigger decoupling capa around our "BUCK-BOOST". (We are at the beginning of our project)

And the configuration data does not take back its default values !

I will try to modify the other cards to see if this is the answer to this problem!

Regards,

Goulwen LE BOZEC.

[Eleon BORLINI]

Hi @GLE B.1​ ,

thank you for your update!

That capacitor could really help to stabilize the supply voltage, smoothing any unwanted spikes.

-Eleon