NPM1304 Watchdog Timer & Power Cycle

RE: NPM1304 Watchdog Timer & Power Cycle

arif__anwar — Sun, 21 Sep 2025 22:05:51 GMT

Morning Vidar

Thanks for clarification. Really appreciate your help.

RE: NPM1304 Watchdog Timer & Power Cycle

Vidar Berg — Wed, 17 Sep 2025 11:23:36 GMT

Hi Arif,

Yes, in the case of a crash, your application should stop reloading the WDT which will cause it to time out and reset the MCU.

RE: NPM1304 Watchdog Timer & Power Cycle

arif__anwar — Tue, 16 Sep 2025 22:03:47 GMT

Morning Vidar

Apologies for the late reply, I've been busy with another project which took up more time than I expected. Just to clarify

1) Functions not supported by the PMIC will be serviced in firmware, my main requirement is that the PMIC reset power to the application hardware IF the watchdog is not serviced (ie MCU has crashed or hung). Is this something the 1304 can do without CPU intervention?

Arif

RE: NPM1304 Watchdog Timer & Power Cycle

Vidar Berg — Fri, 12 Sep 2025 13:19:53 GMT

Hello,

If you're using the nRF Connect SDK, I would recommend considering using the Zephyr watchdog driver to control it. Alternatively you can look at the driver implementation linked below and use it as a reference.

In devicetree:

npm1304_pmic: pmic@3 {
	compatible = "nordic,npm1304";
	
	npm1304_wdt: watchdog {
	compatible = "nordic,npm1304-wdt";
	};
};

Zephyr WDT sample:

https://github.com/nrfconnect/sdk-zephyr/tree/main/samples/drivers/watchdog

npm1304 wdt driver implementation:

https://github.com/nrfconnect/sdk-zephyr/blob/main/drivers/watchdog/wdt_npm13xx.c

[quote userid="147908" url="~/f/nordic-q-a/124307/npm1304-watchdog-timer-power-cycle"]

1) We have a single button in the product, which enables the user to scroll through modes (short presses), can the same button be be used to

generate the power cycle for a 10s press? Would you have application schematics we could follow

[/quote]

The button interrupt would have to be handled on the MCU to trigger other modes which are not supported by the PMIC. Seems like you should still be able to trigger a power cycle:

[quote userid="147908" url="~/f/nordic-q-a/124307/npm1304-watchdog-timer-power-cycle"]2) can the watchdog pat cycle be greater than a day, and can this be achieved when in Sleep Mode?[/quote]

Yes, largest timeout is 74.5 hours:

but the WD cannot be used in ship or hibernate mode:

Best regards,

Vidar