nRF52840 Battery Circuit Design

RE: nRF52840 Battery Circuit Design

Radio — Tue, 28 Jul 2020 11:59:14 GMT

Hi Andreas,

Thank you very much for the support.

RE: nRF52840 Battery Circuit Design

Andreas — Tue, 28 Jul 2020 11:42:20 GMT

Hi,

If you want to enable the chip you should bring the EN to 1.0V or higher. 6V is the max rating and exsceeding that might either damage the device or have it operate out of spec, I do not know this part in detail but you should avoid it.

Best regards,

Andreas

RE: nRF52840 Battery Circuit Design

Radio — Tue, 28 Jul 2020 04:28:51 GMT

Hi Andreas,

Many thanks for the reply. I am bit not clear about the high threshold value and why it is not going to do much in the case.

In the datasheet they mention EN - GND max is 6.0 V. Also EN input high threshold is 1.0 V.

In my case if I am to enable the chip what should I do?

Thanks!

RE: nRF52840 Battery Circuit Design

Andreas — Mon, 27 Jul 2020 13:57:29 GMT

Hi,

1) Ideally you should replicate the instructions from the datasheet. In this case though the idea is probably that there is enough capacitance already on the output that the one 1µF is not needed.

2 and 3) Not sure if this is going to do much in this case, as the high threshold is max 1.0V. The most critical thing I see here is there might not be enough capacitance on the supply, when nRF52840 draws a lot of current the battery will not be able to supply enough current to avoid the voltage dropping. Other than that, running the nRF52840 directly off the battery is generally not a problem.

Best regards,

Andreas