NRF52805 Layout Guidelines

[Gokhun Selcuk]

We plan to use NRF52805 in our existing boards to add BLE functionality. In the PCB guidelines of the NRF52805 there is a notification about the thickness of the PCB being max 0.8mm (shown below).

Note: The distance between the ground plane and the top layer should be less than or equal to 0.8 mm. If this design rule is not followed, Radio parameters may not meet specification.

But our current PCB has a thickness of 1.6mm. We assume we can still use NRF52805 by adjusting the transmission line widths and impedance matching components for the antenna. But we are unsure whether there are some further points to compensate for different PCB thickness. Which parameters should be expect to change/deteriorate and what precautions can be taken against.

Regards  

[Andreas]

Hi,

 

This does not have to do with the transmission line, it is to make sure the ground loop for the decoupling capacitors is as small as possible. If exceeding the specification you might see degraded performance on parameters like modulation characteristics and RX sensitivity. 1.6mm or thicker even is fine, but you will then need an internal ground plane with <0.8mm spacing to the nRF52805 outer layer.

 

Best regards,

Andreas