decoupling capacitor on VDD pin(W1 pin) of nRF52833

[Jingar]

Hello !!

          We are using nRF52833 MCU in our one of project. It is very cost sensitive project. We are proving supply to MCU from coin cell CR2032 battery. Also we enabled DC-DC converter & NFC as per guidance provided into specification sheet.

           Is there necessary to provide 4.7uF decoupling capacitor on VDD (w1 pin) of MCU ? Shall we use 0.1 uF decoupling capacitor as used in another pins ? We shorted VDD & VDDH pins.

Awaiting your feedback

[Andreas]

Hi,

 

This is used to keep the supply voltage stable during spikes of current consumption. If you have sufficient capaticance close enough to the nRF52840 to supply enough current quickly enough, then you do not necessarily need it. Especially coin-cell based applications tend to need this though as there is little else on the board and the coin-cell is not able to provide enough current.

 

Best regards,

Andreas

[Jingar]

Thanks Andras for your prompt response.

In my application, VDD & VDDH pins are directly connected to coin cell battery. There is no another capacitance .May I  know minimum capacitance value required for these pins ?

[Andreas]

Hi,

 

See the effective decoupling capacitance spec. Also make sure you account for derating.

 

Best regards,

Andreas