migrating from nRF52833 to nEF52840

[TheTom]

I like to use nRF52840 now instead of nRF82833 which was used during the CE-RED compliance test.
I only like to change the nRF chip. All other components at the PCB will stay the same. Software of course will be done for the nRF52840.

Questions:

1.
Is it possible just to replace the nRF52833 one by one with the nRF52840 without doing any other changes at the hardware or the antenna design?

2.
Is at nRF52840 the radio front end the same as at nRF52833 so that the Radio EMC / RED will be unaffected?

Thank you for your support and service.

[Kazi Afroza Sultana]

Hello,

1. Is it possible just to replace the nRF52833 one by one with the nRF52840 without doing any other changes at the hardware or the antenna design?

Yes, it is possible to replace. There is a blog about pin to pin compatibility which you can look at  https://devzone.nordicsemi.com/f/nordic-q-a/56958/pin-to-pin-compatibility-info-needed-for-nrf52-ble-socs/230830  .You can check with the package type of both. The pinout is more or less the same. nRF52833 is missing REG0 DCDC and some GPIOs have different numbers, but all pins are on the same place so it is pin compatible. Antenna may need retuning to check if it is tuning properly in accordance with the matching impedance 50 ohm.

2. Is at nRF52840 the radio front end the same as at nRF52833 so that the Radio EMC / RED will be unaffected?

Radio is the same so RED should be unaffected.   

Thanks.

Best Regards,

Kazi Afroza Sultana

[TheTom]

Hello,

Thank you for your answer.

Question:

So I have to tune the antenna design? (In Product Specification they are using different Vallues for thr antenna design of nRF52833 compared to nRF52840.)

[Kazi Afroza Sultana]

Hello,

Changing from nRF52833 to nRF52840 does not effect to antenna, so no tuning is required usually. We do recommend the four component matching network for the nRF52833 and nRF52840 as it filters the harmonics even better.  

You can see the following figure of radio matching network. 

 

Thanks.

Best Regards,

Kazi Afroza Sultana