Does The Npm2100 Have Wakeup On Interrupt?

[SoldOutYungLean]

Planning on using the npm2100 PMIC as our PMIC for an upcoming asset tracking solution.

We will have an accelerometer that will determine when the main MCU (nrf54) wakes up, when the device gets moved.
However, we would also like to utilize the hibernation mode of the npm2100.

Will the npm2100 feature a wake-up GPIO that can be triggered? If not, what would be the fix?

[Edvin]

Hello,

Sorry for the late reply.

The nPM2100 can wake up from hibernate mode either by using the wake-up timer, or by using the SHPHLD pin. During hibernate mode BOOST Vout is discharged and assuming nPM2100 is using its BOOST Vout to power the nRF54, the nRF54 will be powered down. In this case the only way to wake-up the asset tracker is either by an edge on the SHPHLD pin or by using nPM2100's wake-up timer. Please refer to section "7.4 Hibernate mode" in the attached nPM2100 preliminary datasheet for more details.

nPM2100-Preliminary_Datasheet_v0.6.pdf

Best regards,

Edvin

[vielleicht]

Caution to all the readers, "edge" is a misleading term as of: https://devzone.nordicsemi.com/f/nordic-q-a/122983/unexpected-wakeup-from-hibernate-mode-via-shphld-with-rising-edge-configuration-on-npm2100/543328

[Edvin]

Can you elaborate what you mean by misleading? To me it looks like whether you can select whether it is supposed to wake on a rising or falling edge (but not both). 

Best regards,

Edvin

[vielleicht]

Please see the referenced post from Kazi Afroza Sultana, where she mentions that the nPM only checks levels but not edge (i.e. change of level).

we think it should be regarded as level-triggered at all times / in any configuration

[Edvin]

I don't think edge triggering necessarily means that it needs to detect both ways (rising and falling) at the same time. Edge triggering can be both rising-edge triggering, falling-edge triggering, or dual-edge /both edges triggering. The latter one is not supported on the nPM2100's wakeup pin. 

BR,

Edvin

[vielleicht]

To my experience, the nPM2100 does not implement true edge detection in the strict sense. Instead of detecting an actual signal transition (i.e., a discrete event), it monitors the level of the SHPHLD pin.

This means the device evaluates whether the pin is high or low, regardless of when that state was reached. As a result, if the pin is already at the active level when the system enters Hibernate mode, the nPM2100 may wake up immediately — even though no edge occurred.

In other words, the so-called ‘edge’ configuration behaves more like a level-triggered wake-up mechanism rather than a genuine edge-triggered interrupt. So the term ‘edge detection’ in this context is misleading; it is better understood as periodic level sampling rather than event-driven edge sensing.

[Edvin]

I understand. I didn't pick up what you meant initially, but you are saying that the event will occur if you e.g. set it from low-to-high, and the signal was already high (and didn't change). I was not aware. In that case, I agree. I will take it forward to our pmic team.

Best regards,

Edvin