topic Re: MKL03Z8 Sleep Current too high in Kinetis Microcontrollers

MKL03Z8 Sleep Current too high

micaelsantos — Fri, 25 Nov 2016 19:11:52 GMT

I've been trying to get a MKL03Z8 device to enter low power mode with the code attached, but I can't get less than 192uA. Looking at the datasheet the VPLS mode should be around 2.2uA. I already tried disabling clocks, seeing if there are any floating pins but no luck so far.

What could be the source of this high consumption? I'm running out of ideas to try. Is there any simple code example where I can get the specified currents in the datasheet? That way I could see what I was doing wrong.

I've tried looking into the example on the SDK but it didn't help much. This product is meant to be used with batteries sleeping currents can be a deal breaker.

Thanks in advance for the help

Original Attachment has been moved to: Test.zip

Re: MKL03Z8 Sleep Current too high

mjbcswitzerland — Fri, 25 Nov 2016 22:54:03 GMT

One reason for high consumption is floating inputs - make sure that you either drive unused pins or switch internal pull-ups on them. Also ensure not to leave peripheral inputs floating (again it is best to switch a pull-up on such inputs).

In case of SW difficulties there is a complete solution (including automatic switching between power modes to optimise consumption and wake ups from modules or pins) at the links below.
The KL03 link includes a FRDM-KL03 application which allows switching between modes in order to measure the current which achieves about that specified in the documents.

Regards

Mark

Kinetis for Professionals: http://www.utasker.com/kinetis.html
KL03: http://www.utasker.com/kinetis/FRDM-KL03Z.html
LLWU: http://www.utasker.com/kinetis/LLWU.html

Re: MKL03Z8 Sleep Current too high

micaelsantos — Mon, 28 Nov 2016 16:27:57 GMT

I already found the problem after some research here and there. There is a bug on the microcontroller related to the RTC mentioned on the errata. So after POR reset we need to do the code bellow

SIM->SCGC6 |= SIM_SCGC6_RTC_MASK;

RTC->TSR = 0x00;
SIM->SCGC6 &= ~SIM_SCGC6_RTC_MASK;

Maybe it saves someone in the future :smileyhappy: