Can't achieve low power with PCA10028

RE: Can't achieve low power with PCA10028

Lee Daniel Crocker — Tue, 17 Nov 2015 21:44:53 GMT

Not in the PCA10028 itself. The custom board I was really interested in did manage to get down into the microamp range by letting the softdevice manage power and making sure everything was turned off when not being used (even things like the SPI bus and the ADC).

RE: Can't achieve low power with PCA10028

jmag999 — Tue, 17 Nov 2015 20:26:08 GMT

Did you every solve this? I am trying to get down to the specified <3uA range with the PCA10028. I seem to hit a low of about 28uA.

RE: Can't achieve low power with PCA10028

FormerMember — Mon, 21 Sep 2015 23:13:17 GMT

Try a power cycle. Worked for me when I was measuring the power with nrf51 DK. Don't remember if I also did a pin reset.

RE: Can't achieve low power with PCA10028

Lee Daniel Crocker — Mon, 21 Sep 2015 21:41:11 GMT

The PCA10028 has a specific current measurement port and very detailed instructions...cut a solder bridge, put in a 10 ohm resistor, measure across these two pins. I'm following that to the letter. Looks like I may just have to add some pins to my production board and measure it there.

RE: Can't achieve low power with PCA10028

Michael Dietz — Mon, 21 Sep 2015 21:26:16 GMT

I wonder if its the interface MCU that is drawing this current. Have you eliminated the possibility of this? I'm really not sure about this so look into it yourself but I think the interface mcu makes it a bit difficult to measure current. it shares the same VCC with the nrf device and I think this is also in the current measure port. but if you look closely on the schematic you should be able to find a VCC_NRF or something like that on a pin out. and maybe try to measure there?

RE: Can't achieve low power with PCA10028

Susheel Nuguru — Mon, 21 Sep 2015 20:04:01 GMT

Ah, i missed to see that there is no softdevice, it cannot be this high with power after system off as you have not started any clocks and you also made sure that the chip is in LOWPWR mode.

RE: Can't achieve low power with PCA10028

Lee Daniel Crocker — Mon, 21 Sep 2015 18:15:51 GMT

Thanks, the while (1) {} didn't do it. The settings above I believe are both banks on when in ON mode and both off when in OFF mode. But even with the ram banks on, I shouldn't be getting a number this big. I'm not entirely sure I trust my measurements, so I'll investigate that for a while, but I don't think they're off by a factor of 1000.

RE: Can't achieve low power with PCA10028

Susheel Nuguru — Mon, 21 Sep 2015 17:53:42 GMT

i am not sure if this would help, but i think there should be a while(1): in the end of the main function, else it will end up in hardfault handler.
Also i do not have the bitfield and product doc in hand, not sure what is going on with RAMON settings, are you switching it off or on? seems like your are doing both in one go?