npm1300 on-off switch question

RE: npm1300 on-off switch question

ecp — Tue, 03 Mar 2026 11:58:27 GMT

but a pushbutton connected to the SHPHLD pin could be configured through software of the NPM1300 to generate an interrupt through one of its GPIOs when pressed. This GPIO would connect to a GPIO on the SoC, which could be configured to tell the NPM1300 through I2C to go into ship mode when this interrupt is received for a decided amount of time (5 second button press for example).
Is this correct?

RE: npm1300 on-off switch question

Tomi Koskela — Tue, 03 Mar 2026 11:41:45 GMT

In ship mode the battery is effectively isolated from the system and it cannot be charged. Yes connecting USB will wake up the nPM1300 from ship mode. Unfortunately it is not possible to enter ship mode with push button, only with TWI write.

RE: npm1300 on-off switch question

ecp — Tue, 03 Mar 2026 10:29:01 GMT

Can the battery be charged through USB while in ship mode? I read in the datasheet that connecting the USB wakes up the npm1300 from ship mode.
Also, is it possible to set up a pushbutton to enter ship mode?

RE: npm1300 on-off switch question

Tomi Koskela — Tue, 03 Mar 2026 10:09:58 GMT

In the example schematic you would use ship mode to turn off the system (entered with TWI write) and SHPHLD pin for waking up. VDDIO needs to be powered for TWI operation. If VDDIO is not present you would not be able to communicate with the device. Note the GPIO is also referenced to VDDIO.

RE: npm1300 on-off switch question

ecp — Tue, 03 Mar 2026 09:55:57 GMT

If the circuit is wired as in this example, how can you turn off the SoC by turning off the BUCK that powers it if VDDIO needs to be powered by that same BUCK?

Or stated differently: how would you turn the system off in this application example? (while still being able to charge the battery while off through USB). And how would you then turn it back on?

RE: npm1300 on-off switch question

Tomi Koskela — Tue, 03 Mar 2026 07:12:40 GMT

In typical application buck converter is used to supply VDDIO, the same rail that would power the SoC. This same rail would be the reference voltage for SoC TWI. One suggestion is using the same supply as you have for the device that controls the GPIO in this state.

RE: npm1300 on-off switch question

ecp — Mon, 02 Mar 2026 21:25:14 GMT

When I do this, configuring the bucks on/off through a GPIO, it gets into an invalid state upon turning off the buck that feeds the VDDIO. What should the VDDIO be connected to in order for this not to happen? The datasheet only recommends powering VDDIO with one of the bucks.

RE: npm1300 on-off switch question

Tomi Koskela — Fri, 28 Mar 2025 09:53:25 GMT

VSET1/VSET2 are monitored only on startup. So you cannot disable/enable the bucks with this connection "on the fly". You would need to configure the bucks to be controlled with GPIO (needs TWI writes to accomplish this) and then you could control the bucks with a switch.

RE: npm1300 on-off switch question

ecp — Thu, 27 Mar 2025 16:12:02 GMT

Does this mean that if I add a switch that shorts VSET1 and VSET2 pins to ground like in the image below, it can act as an on/off switch for the system?

Thanks,

-Eduardo

RE: npm1300 on-off switch question

runsiv — Thu, 27 Mar 2025 10:11:21 GMT

You have three options that is described here

Regards

Runar

RE: npm1300 on-off switch question

ecp — Thu, 27 Mar 2025 00:48:51 GMT

What are the ways I could explicitly turn off the buck converters?

RE: npm1300 on-off switch question

runsiv — Tue, 25 Mar 2025 12:15:34 GMT

That is expected, disconnected PVDD when the BUCKs are not explicitly turned OFF is not possible.

As for how to achieve this, I don't quite see an obvious way besides using a double-pole switch (DPST) and disconnecting the outputs of the BUCK from what they supply and let them idle in HYST mode.

Regards

Runar

RE: npm1300 on-off switch question

runsiv — Fri, 21 Mar 2025 11:45:12 GMT

I have asked the PMIC team and will get back to you as soon as I hear from them

Regards

Runar