Using VDD_PA on the nRF24L01/+ to power another microcontroller

[Jay]

Hi everyone,

I was looking to use the nRF24L01/+ along with a small microcontroller (e.g., ATtiny) and I wanted to reduce the BoM as much as possible. I was planning to use the ATtiny for simple processing where it should use less than ~1 mA of current at 1.8V and was wondering if I could use the VDD_PA output as the power source for the ATtiny. I wasn't able to find any more information (e.g., maximum output current and what happens to the pin when nRF24 is in power saving mode) in the datasheet..

If it is possible to use VDD_PA to power another microcontroller, what happens to the VDD_PA pin when the nRF24L01/+ goes down to power saving mode? Does it stop outputting current all together?

Thank you for your help!

[Simonr]

Hi Jay

No, this won't be possible.VDD_PA can only be used as a signal to PA/LNA. It will only be high when the radio is in TX, an will not output anything when the nRF24L01 is in power saving mode, or any other mode than TX for that matter.

Best regards,

Simon