Migrating nRF52840 to nRF52833

[mtorti]

Hi,

Checking the new nRF52833, i saw that it has the same package as nRF52840.

Considering to migrate from nRF52840 to nRF52833, i checked the recommended schematics and found out the only difference is the ANT circuit.

On 52840 it has 2 caps and 1 inductor, and in 52833 it has 2 caps and 2 inductors of different values.

For the legacy products, it is acceptable to put the 52833 on the 52840 schematics (with 2 caps and 1 inductor), or the performance may be decreased a lot?

It would be interesting to direct replace the ic without making new PCBs.

[Marjeris Romero]

Hi Maximiliano,

It will depend. You will have to measure the RF TX harmonics and tune the RF matching network if needed. If you want you can send us at least 2 PCBs with the nRF52833 and we can help you with the tuning.

Best regards,

Marjeris

[Bill Choi]

Can I ask why you are migrating from nRF52840 to nRF52833 ?

[chethans]

NRF52833 has higher operating temperature, up to 105 deg

[chethans]

Marjeris Romero One more change from 52840 to 52833 is the additional NC cap on DEC2 pin. Currently we do not have this cap due to space constraints. Is there any scenario where this would be required?

[Marjeris Romero]

Hi chethans,

Sorry for the late reply. If you are referring to the N.C capacitor C13 connected to DEC2 pin in the nRF52840 aQFN73 reference design, it was laid out in case of any issues or something else required an extra decoupling, but it was rarely never needed, so it is up to you if you want to keep it in your design or not. In the nRF52833 the same pin (A18) should be kept N.C.

If you want a closer review of your design please feel free to open a private Devzone ticket and we will give you a more in-depth review.

Best regards,

Marjeris