Power Switching Solution for Battery + Wireless Charging Design

[aathil]

Hi everyone,
I’m working on a low-power BLE smart tag using nRF54L15 and nPM1300 PMIC. My requirement is:

When no charger is connected → the system should run from the 3.7 V Li-ion battery.

When wireless/wired charging is active (5 V to VBUS) → the system must remain OFF, and only the battery should charge.

Once charging is disconnected → the system should automatically power back on from the battery.

I’m currently exploring two options:
1️⃣ Using a load switch / ideal-diode controller to disconnect the 3.3 V rail during charging
2️⃣ Using a PMIC-driven control signal (e.g., VBUSOUT) to gate system power

Question:
 Are there any reliable, compact power-switching ICs you recommend for handling this “charge-only mode” automatically or can i achive this using NPM1300?

Any insights, recommended ICs, or reference designs are greatly appreciated! 

Thanks in advance!

[Priyanka]

Hi,

You could use the nPM1300 for this. When the VBUS is present, there will be a VBUSOUT. 

So one possibility is that, you could have a flag of VBUS presence on a GPIO, then loop it to another GPIO that would enable/disable the BUCK. 

Hence, when there is VBUS present, the GPIO causes BUCKs to be disabled, and viceversa when the VBUS is removed.

You could do this, but controlling one of the internal load switches with a GPIO and keeping the DCDC ON.

-Priyanka