https://devzone.nordicsemi.com/f/nordic-q-a/17940/my-nrf52-resets-after-killing-power-to-an-external-gpio-controllerI am working on a battery-powered application. Since power saving is a must, this design using high-side power node controllers (part number MIC94042) to power-on or power-off specific voltage nodes that power specific peripherals. These peripheralsen-USTelligent Community 13Fri, 25 Nov 2016 09:49:37 GMThttps://devzone.nordicsemi.com/thread/69194?ContentTypeID=1Fri, 25 Nov 2016 09:49:37 GMT137ad170-7792-4731-bb38-c0d22fbe4515:e5a0d2e4-0eee-4d82-9634-5c1c438df4d2Hung Bui<p>@Noah: You should also check if there is any assertion and in your assert handler you reset the chip. Remove the code that reset, or add a breakpoint inside the assert handler could help.</p> <p>You may want to add a schematic or figure explaining your setup, it could help also.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/69195?ContentTypeID=1Thu, 24 Nov 2016 11:54:40 GMT137ad170-7792-4731-bb38-c0d22fbe4515:1f8fdf0c-5272-4146-8343-f311a0529c36Alex<p>What do you do with CS of MCP23S17 when you power it down? Just make sure all nRF52 IOs connected to powered down peripherals do not output high level in power down mode.</p><div style="clear:both;"></div>