npm1300 Buck regulator merging

[Anand97]

Hi Team,

I'm analyzing to use nPM1300 PMIC in one of my projects. I planned to use the integrated Buck to power my on-board device. But, the calculated current consumption is way more than the Buck output (200mA). Since there are two Buck in the PMIC, i thought of merging them through Ideal diode to increase supply current. Is this method advisable? or any other recommended method to supply for higher load?

Thanks in advance.

Regards,

Anand M

[Simonr]

Hi

I've gotten some feedback now and here's our suggestions:

The two bucks can be set at the same voltage, but not connected, as even a very small difference in the output voltage would result in one buck pushing current to the output of the other. Using an ideal diode might work, but it's not something we've tested or can guarantee that will. But it sounds doable.

A suggestion to how to do so would be something like this: Create net names of 3.3VA and 3.3VB in the schematic, so that the variation in output voltage won't affect 2 parts communicating with separate power nets. Make sure to keep these nets separated in their connections. 

Another alternative could be too connect VSYS of the nPM1300 as an input to nPM6001, as the nPM6001 has a 550mA step-down converter.

Best regards,

Simon

[Anand97]

Hi Simon,

Thanks for the clarification. My intention to use the internal regulators of nPM1300 to save space and BOM. As you said, if I go with separate net names for both BUCK1 & BUCK2 and connect them to ideal diode, it shouldn't cause any harm right?

And, the problem with using nPM6001 is WLCSP package.

Regards,

Anand M