Matching impedance between WB09 and MLPF-NRG-01D3

[EIvan.2]

In the documentation for STM32WB09 it is written that the output impedance of the chip is 40 ohms. It is also written in the document AN5526 on page 5. And in the documentation for MLPF-NRG-01D3 chip it is written: Transmission line between STM32 and MLPF is dimensioned to 57 ohms characteristic impedance.

What should be the impedance of the transmission line between STM32 and MLPF?

And another question, in the same AN5526 document it says that the thickness of the double layer PCB should be 0.5mm.
At the same time there is a two-layer board STEVAL-IDB012V1. Does it really have a board thickness of 0.5mm? If the thickness is 1.5mm, can 1.5mm boards be used with the STM32WB09 chip?

[STTwo-32]

Hello @EIvan.2 

What should be the impedance of the transmission line between STM32 and MLPF?

Transmission line between STM32 and MLPF is dimensioned to 57 ohms characteristic impedance. Theses transmission line characteristics impedances must be followed as close as possible. The MLPF-NRG-01D3 has been optimized to be well matched including the 40 ohm impedance of STM32WB09 and including the 57 ohm characteristic impedance. Please follow the datashet and application note recommendation to have good matching.

> In the same AN5526 document it says that the thickness of the double layer PCB should be 0.5mm.
At the same time there is a two-layer board STEVAL-IDB012V1. Does it really have a board thickness of 0.5mm? If the thickness is 1.5mm, can 1.5mm boards be used with the STM32WB09 chip?

0.5 mm is what have been used in the board validation, if the thickness is higher it should not be an issue, this is assuming the recommendation at top  layer 1 are respected  and characteristic impedance are close to recommendation, this mean lines width adjusted depending on the board thickness.  

Best Regards.

STTwo-32