Power management- usuing external LFCLK

[Gili Elias]

Hi, I'm trying to reduce as much as I can the BLE current consumption in advertise mode and unfortunately I can't go under 1.6 mA. Can you please tell me what are the exact steps I should take to do that? What I want to do is to advertise with the defined interval on SYSTEM-ON base current with 16 kB RAM enabled. My current, as I understand it, should be around 2.6 uA, but I can't reach it.

I use an external Crystal LFCLK. How should I define the ble_stack_init? how should I define the timer_init and start_timer functions to use only in the LFCLK and not in HFCLK? For low current between advertises I use sd_app_evt_wait() function. Still, because of my stcak (probably) I can't reach the low current of 2.6 uA.

What's makes the current so high? What are the recommended settings to make the component work in minimum current?

Thanks.

[Gili Elias]

Hi Ole,

Thanks for the reply. We are currently at ~130uA and probably what is going on is we still have some fast clock peripheral on, so we will take a look.

Regards, Gili

[Ole Morten]

130 µA was an odd level, and I can't say I immediately have any good suggestions on which peripheral combination would draw that. I'd recommend you to also make sure that all I/Os have a defined level (i.e. not input without pull; either output, input with pull or input buffer disconnected).

Also, you should make sure to do the measurement without a debugger connected, either physically disconnect it or turn it off with the SW4 switch or removing the P8 jumpters on the Evaluation Kit.

Finally, if you have the Development Kit, you should not use the CSM to do low-current measurements, but instead measure current directly on P7.