The question of cap of DEC 2 of nRF52832 (QFN)

[Hsu]

Hi Sir,

In the latest datasheet (52832_v1.4), our reference schematic shows the cap (C6) of DEC2 can be NC.

For DEC2, it is 1.3V regulator supply for Radio, may I know why the C6 can keep in NC?

Any side effect if we mount the C6 (100pF) for DEC2?

Thank you.

BRs, Han

[Andreas]

Hi,

 
DEC2 mounting is different in QFN and WLCSP parts, it is to be mounted (100pF) in the WLCSP part but not mounted in the QFN part. Mounting it in the QFN part will lower the RX sensitivity by a couple of dB when using the internal DCDC converter. Note also that this is the circuitry that is characterized and verified, if you load it differently from our reference design you do so on your own risk.

 

Best regards,

Andreas

[Hsu]

Hi Andreas,

Thanks for the update.

" will lower the RX sensitivity by a couple of dB when using the internal DCDC converter. " 

Does it mean if the system use LDO mode, it will not affect the RX sensitivity?

Thank you.

BRs, Han

[Andreas]

Hi,

 

The point is DEC2 is not to be populated at all, in which case the sensitivity will not be affected in either LDO or DCDC mode.

 

Best regards,

Andreas