LFSYNT power consumption

[bart]

Hi, I'm wondering how much i need the LF crystal oscillator.

In this case, the chip is never asleep, in constant latency mode, and is constantly advertising and meshing.

The documentation mentions that LFSYNT consumes 100 μA. Is this on top of the consumption of the running cpu?

[Jørgen Holmefjord]

Hi,

It is not recommended to use LFSYNT if not having the external crystal. Not only will it consume the extra LFSYNT run current of 100 uA, it will also force the HFCLK to run at all times, adding the additional HFXO run current of 250 uA.

A better alternative is to use the LFRC oscillator, consuming much less current. You can read more about the different clock sources in this answer, and about the RC oscillator current consumption in this thread.

Best regards,

Jørgen

[bart]

The 250uA is also added when already running in constant latency mode? And is the added current consumption the only downside, or are there other things to consider too?