Bypass capacitor placement

[DihydrogenMonoxide]

My project uses a BME280 for measuring temperature and humidity. This device requires 2 capacitors but also thermal decoupling from the rest of the board.

Because I won't be doing a copper fill near the BME280, I need to decide whether the caps should be closer to the ground plane or closer to the sensor.

Which approach is better here?

 

[d123]

Hi,

...Be dihydrogen monoxide, my friend...

Usual recommendation for bypassing capacitors is as close to the pins of interest as possible.

Altium article:
Bypass and Decoupling Capacitor Placement Guidelines

Analog Devices pdf:
**broken link removed**

 

[KlausST]

Hi,

The whole loop is that matters. If one part of the loop is bad, the whole loop is bad.
Read about
* lengthy wiring
* wiring impedance
* area enclosed by the loop
....

Klaus

 

[emresel]

Hi;
Couldn't be this a reference for you? It seems it is an already in use application
https://www.reichelt.com/de/en/deve...d-pressure-sensor-bm-debo-bme280-p253982.html