Why NRF51x GPIOTE input mode static current consumpts so high?

RE: Why NRF51x GPIOTE input mode static current consumpts so high?

Lars Sundell — Tue, 05 Jul 2016 07:04:46 GMT

I was a inaccurate in my prevoius answer PrithviRaj, I mixed up the root cause for the numbers for nRF51 and nRF52. As Stefan correctly points out the current consumption for using GPIOTE in input mode in nRF51 is severe. The root case is that clock is requested, see table 33 in the Product specification, version 3.2. In nRF52 this need for clock is removed and we are left with the current caused by a larger part of the design being on.

RE: Why NRF51x GPIOTE input mode static current consumpts so high?

Stefan Birnir Sverrisson — Mon, 04 Jul 2016 16:02:34 GMT

As both Lars Sundell and PrithviRaj Narendra have pointed out, use PORT event for low power nRF51 applications. The current consumption is <<1uA, while the GPIOTE IN current consumption is ~1mA. The gpiote driver in SDK 11.0.0 implements the tuning Lars mentions in his comment. The GPIOTE PORT event should work equally well as GPIOTE IN events if you use the gpiote driver, with the exception when the pin signal changes faster than ~100Hz, then there is a chance that pin signal change is not captured when using PORT event.

RE: Why NRF51x GPIOTE input mode static current consumpts so high?

Lars Sundell — Mon, 04 Jul 2016 05:48:59 GMT

The root cause for the elevated currnet consuption is increased lakage dur to a larger part of the device has to be powered for the GPIOTE input mode to be on. Unfortunately that explanation does not help in your case, and as PrithviRaj Narendra points out. PORT event is the recommended solution.

RE: Why NRF51x GPIOTE input mode static current consumpts so high?

Songplus — Mon, 04 Jul 2016 03:46:23 GMT

Thank you for your answer.I have found a way to avoid using the GPIOTE,but it will raise cost,and have to change the sheet design .I think my problem is not difficult to answer for a Nordic engineers,why couldn't give me a directly explanation as PrithviRaj Narendra's answer.It is little dispointed.

RE: Why NRF51x GPIOTE input mode static current consumpts so high?

Songplus — Mon, 04 Jul 2016 03:28:02 GMT

Thank you for you answer.You know,In some applications,especially low power consum products,22uA is very very high current for a cell battery powers.Yeasterday,I found a way to solution the chip bug.I will consider of the nRF52x at the next generation products

RE: Why NRF51x GPIOTE input mode static current consumpts so high?

FormerMember — Wed, 29 Jun 2016 11:08:37 GMT

Yes, its high current consumption. I'll be interested in knowing why this is so, although as a system developer I don't need this info as I can't fix it. I just work with knowing that GPIOTE input channels take 22 uA.

Not sure if Nordic will explain to us their design causing the 22 uA consumption. They've fixed it in nRF52 where its in nA.

RE: Why NRF51x GPIOTE input mode static current consumpts so high?

Lars Sundell — Wed, 29 Jun 2016 09:18:49 GMT

I see that the support team has not answered this yet (probably because they find the answer provided by PrithviRaj Narendra correct). I am part of the design team and can confirm that PORT event is the best solution to ensure as low power consumption as possible. Using PORT event will give you the Igpio,idle current consumption. Please not that PORT event will not give you edge triggering, only level, so the IRQ handler may need some tuning if you need edge detect.

RE: Why NRF51x GPIOTE input mode static current consumpts so high?

Songplus — Wed, 29 Jun 2016 02:57:06 GMT

SOS ....I need a professional answer.Where are the Nordic engineers? Why the chip's GPIOTE consums current so high?

RE: Why NRF51x GPIOTE input mode static current consumpts so high?

Songplus — Tue, 28 Jun 2016 01:36:41 GMT

I know how to use the GPIOTE,what I care is the GPIOTE current consumption.I think the GPIOTE intrrupt is a big bug design, I 'd never seem MUC's gpio intterup consum so high current.

RE: Why NRF51x GPIOTE input mode static current consumpts so high?

FormerMember — Mon, 27 Jun 2016 10:31:07 GMT

If your aim is to wake up from sleep, then the PORT event is your best bet. For all the required pins in GPIO peripheral set the SENSE field in PIN_CNF[n] as High or Low with the input buffer connected.

Next enable the GPIOTE PORT event's interrupt. This will cause the system to wake up, even from the OFF mode. In the ON mode, you can check which pin triggered the PORT event in the GPIOTE IRQ handler to do the appropriate next step.

RE: Why NRF51x GPIOTE input mode static current consumpts so high?

Songplus — Mon, 27 Jun 2016 01:55:44 GMT

PS, my English is not good, so be patience to read it over ^_^