nRF5340-CMAA replacement?

[Greg0]

For just a first test board off of Thingy 91x design, can nRF5340-CMAA be replaced with nRF5340-CLAA? What's the downside of doing that? Documentation says it's not recommended for new designs, but can't find details.

[Samuel Carey]

Can you please confirm if the CLAA will or will not fit on CMAA pads? Also, please confirm that the RF will require different matching characteristics. The CMAA is currently unavailable and I need to know if I can use CLAA as a replacement.

[Samruddhi Jadhav]

Hi Samuel,

As I mentioned in my previous response, CMAA has larger solder balls than CLAA. To compare this it is 0.19-0.25mm vs 0.12-0.18mm. This can result in problems with the soldering as CMAA footprint has larger pads than CLAA. It should be fine to solder a CLAA on a CMAA footprint but we do not recommend that you do this in production. You also don't have to change anything in the radio match as CLAA and CMAA have the same matching network. 

Please let us know if you have any further questions.

Best Regards,

Samruddhi