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Associate
June 10, 2025
Solved

LIS2DH12 bypass capacitor

  • June 10, 2025
  • 2 replies
  • 474 views

Hi, I'm putting down a LIS2DH12 accelerometer on a new PCB. The datasheet calls for an aluminum capacitor on VDD, but the eval board (STEVAL-MKI151V1) shows a small capacitor that looks like a ceramic. I don't know for sure because I can't find the BOM for the eval board. I really don't have clearance for an electrolytic capacitor. How critical is it?

Best answer by Federica Bossi

Hi @sparky619 ,

The purpose of 10uF capacitor is to have a tank capacitor close the device. It is also possible to use MLCC capacitor instead of aluminum type.

2 replies

Andrew Neil
Super User
June 10, 2025
A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
sparky619Author
Associate
June 10, 2025

Thank you!

sparky619Author
Associate
June 10, 2025

BOM lists that capacitor as a generic polarized.. but the silkscreen is not marked with polarity and the gerbers do not show the right size for a polarized capacitor. Still wondering why a polarized capacitor is called out in the datasheet for the sensor.

Federica Bossi
Federica BossiBest answer
Technical Moderator
June 12, 2025

Hi @sparky619 ,

The purpose of 10uF capacitor is to have a tank capacitor close the device. It is also possible to use MLCC capacitor instead of aluminum type.

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Andrew Neil
Super User
June 12, 2025

@Federica Bossi wrote:

It is also possible to use MLCC capacitor instead of aluminum type.


So the datasheet should be updated to reflect this:

AndrewNeil_0-1749724575544.png

https://www.st.com/resource/en/datasheet/lis2dh12.pdf#page=20

 

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.