System power off current consumption in nrf51422

RE: System power off current consumption in nrf51422

soumil — Wed, 05 Oct 2016 06:57:52 GMT

Yes in system power off mode i am getting 16 ua while in low power system on mode i am getting current of 25ua.

RE: System power off current consumption in nrf51422

Øyvind Karlsen — Wed, 05 Oct 2016 06:49:19 GMT

Didn't you describe that you were getting 16µA and 25µA?

You should see the current measurement guides (part 1, part 2) for further explanations.

RE: System power off current consumption in nrf51422

soumil — Wed, 05 Oct 2016 06:15:21 GMT

Okay sure i get this. If i am getting the same sleep current for all the applications that is around 25 ua then is the multimeter I am using doing some averaging and not giving me the accurate sleep current?

RE: System power off current consumption in nrf51422

Øyvind Karlsen — Wed, 05 Oct 2016 05:58:00 GMT

First off you'll need to restrict yourself to one example, such as your application. Then you need to be sure that you are actually turning off all peripherals so that you are actually in the sleep condition you expect, e.g. if you run a timer it will increase your current draw.

Finally it may be that you are measuring dynamic current and not sleep current, in order to measure the sleep current reliably you will have to ensure that your measuring equipment is good enough for the expected sleep time you try to measure. A common example is if you use a cheap multimeter, with some form of averaging. In this case you will see the TX/RX/CPU active current draw as part of what you expected to be sleep current.

RE: System power off current consumption in nrf51422

soumil — Tue, 04 Oct 2016 12:34:39 GMT

Any reason for getting high current?. I am still getting higher current in sleep mode.

RE: System power off current consumption in nrf51422

soumil — Thu, 01 Sep 2016 06:19:18 GMT

No this is not the same code. This code is the heart rate example that comes with the SDK and the current consumption comes out to be 25 ua.

RE: System power off current consumption in nrf51422

Øyvind Karlsen — Sat, 20 Aug 2016 16:03:50 GMT

Is this with the same code? Current consumption is very code dependent.

RE: System power off current consumption in nrf51422

soumil — Tue, 16 Aug 2016 08:02:41 GMT

Hi Peter, i just loaded the heart rate example which uses the system low power mode and the current consumption is coming out to be 25uA. I don't think this is the value we expect. Is there something i am doing wrong.

RE: System power off current consumption in nrf51422

soumil — Mon, 08 Aug 2016 12:23:07 GMT

I will check that and get back to you

RE: System power off current consumption in nrf51422

Øyvind Karlsen — Mon, 08 Aug 2016 12:21:01 GMT

Are you able to test the current consumption of your code by flashing it to the development kit and measuring the draw there?

RE: System power off current consumption in nrf51422

soumil — Mon, 08 Aug 2016 12:19:59 GMT

I am not retaining any of the RAM contents. I am using pstorage to retain data in flash memory. Any other reason on why we are getting high sleep current

RE: System power off current consumption in nrf51422

Øyvind Karlsen — Mon, 08 Aug 2016 12:14:50 GMT

Hi,

The current in system off is specified as 0.6 µA, alternately 1.6 µA if used in low voltage mode. Then you add 0.6 µA for each 8 kB block of RAM you retain. I would current draw from look pull resistors, diode leakage etc for the final µAs.

Best regards,

Øyvind