LFSYNT power consumption

RE: LFSYNT power consumption

bart — Wed, 28 Jun 2017 12:44:23 GMT

Ok, so basically just because it's not tested. Thanks.

RE: LFSYNT power consumption

Jørgen Holmefjord — Wed, 28 Jun 2017 11:49:26 GMT

Yes, in constant latency mode the HFCLK is forced on as well. I'm not aware of any other downsides than current consumption, but it is not intended for, or have been tested for use with BLE.

RE: LFSYNT power consumption

bart — Wed, 28 Jun 2017 10:03:59 GMT

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?

RE: LFSYNT power consumption

Jørgen Holmefjord — Wed, 28 Jun 2017 08:57:55 GMT

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