nPM1300 VOUT timing?

RE: nPM1300 VOUT timing?

pejetro — Wed, 24 Sep 2025 06:57:54 GMT

I understand Ressa,

Thank you very much for your support.

BR Per

RE: nPM1300 VOUT timing?

Ressa — Tue, 23 Sep 2025 11:11:23 GMT

Yes it will start and the default voltage will be determined by the resistor values on VSET pin.

RE: nPM1300 VOUT timing?

pejetro — Tue, 23 Sep 2025 10:46:17 GMT

Thank you very much for your quick reply Ressa.

As you write, the buck can be controlled by software,

but it will startup automatically during power-up, won't it?

If not, our system will never be able to start!

BR Per

RE: nPM1300 VOUT timing?

Ressa — Tue, 23 Sep 2025 10:40:58 GMT

Hi,

Regarding VSYS and VOUT2, if battery is connected and PMIC is active then VBAT will be seen on the VSYS. Also VSYS is the supply for buck (VOUT2) so VSYS needs to be present before buck can start. Buck startup time is 1.2ms so this is the time that it takes from enabling buck to get it on pin. You can control the buck through software TWI interface if you want more specific timing and voltage.
Here is the diagram from datasheet:

Best regards,
Ressa