XC9236 on nRF9160 UVLO when supplying power to external devices

RE: XC9236 on nRF9160 UVLO when supplying power to external devices

Stian Røed Hafskjold — Thu, 03 Nov 2022 14:08:59 GMT

Hi, I'm not able to reproduce this here. Are you able to measure the XC9236 output on TP50, to rule out that it's not the VIO_REF voltage follower that is the problem here? Thanks.

How is the external device connected to the DK? On P20 or the 10 pin SWD debug out connector, which pins are being used, etc. Does the external board use power from the DK, or is it powered from a separate supply, and if so, at which voltage? Or are you able to reproduce this without any connections to the external device?

RE: XC9236 on nRF9160 UVLO when supplying power to external devices

Jared — Mon, 31 Oct 2022 21:00:52 GMT

Thanks Stian!

RE: XC9236 on nRF9160 UVLO when supplying power to external devices

Stian Røed Hafskjold — Mon, 31 Oct 2022 20:55:00 GMT

Hi Jared, thanks for the description. I will try this on a DK and get back to you soon.

RE: XC9236 on nRF9160 UVLO when supplying power to external devices

Jared — Fri, 28 Oct 2022 13:29:35 GMT

Hi Kaja

Sorry but this isn't what I'm talking about.

The XC9236 latches off and does not power back on without a power cycle. Please try on an DK as I've described before.

RE: XC9236 on nRF9160 UVLO when supplying power to external devices

Kaja — Thu, 27 Oct 2022 08:23:16 GMT

Hi Jared,

I don’t have access to a DK now, so I can’t reproduce it at the moment.

But VTG is a detect pin, to select to connect the debugger to en external device.

Can be that when you connect to the VTG, while power is on, you get an unsupported stat, so that you need to repower again. Because you switch what device the debugger is connected to.

Best regards,

Kaja

RE: XC9236 on nRF9160 UVLO when supplying power to external devices

Kaja — Wed, 26 Oct 2022 14:00:44 GMT

Hi Jared,

sorry for the delay, I will have a look at this tomorrow.

Best regards,
Kaja

RE: XC9236 on nRF9160 UVLO when supplying power to external devices

Jared — Tue, 25 Oct 2022 15:42:04 GMT

Removed D10 and shorted. Still happens.

RE: XC9236 on nRF9160 UVLO when supplying power to external devices

Jared — Tue, 25 Oct 2022 03:15:56 GMT

Additionally I'll add that when the device is pre-connected during power-on everything works ok. An easy way to reproduce this is by removing the jumper on P22 while powered on and replace it. (It should cause the same brown out)

RE: XC9236 on nRF9160 UVLO when supplying power to external devices

Jared — Tue, 25 Oct 2022 02:23:23 GMT

External device = un-programmed nRF9160