TPSM82810: Parallel supply for increased current capacity and output capacitance

Hi Dan,

This is a way to parallel any 2 DC/DC converters: 

Do you have 800uF of ceramic cap?  If some of that has ESR, it greatly helps stability.

Thanks Chris,

They're all ceramic caps. Unfortunately PTE design eliminates electrolytics.

It could be more than 844µF since I haven't worked out what caps are needed for one of the supply pins.

1x 330µF ­±20%
4x 100µF ­±20%
2x 47µF ­±20%
2x10µF ­±20%
?x ??µF

Thank you for that document. I'll need to take a closer look at it and see if we would prefer to implement it.
I was wrong about the two supplies. The supply that requires >4A is the same one that requires ≥844µF.

Kind regards,
Dan

Why do you 'need' so much cap?

Is it possible to add a resistor to create ESR?  Even if you can't, it might be stable just from the impedance of PCB trace and/or ferrite beads in the output path.

For higher currents that can also support more output cap, we have LMZ30606.  We also have the older PTH04T231W and PTH05050W.

Thanks Chris,

I don't think we can use load sharing resistors since the supply is for the core of our processor. The current consumed will vary depending on what the processor is doing. Since VDC must be incremented in order to compensate for the current consumed, our core voltage will have too much variation.

The capacitors are determined by the Xilinx Ultrascale+ requirements. This core supply needs significantly more than I anticipated.

Is there a ≥10A regulator that you would recommend with efficient board space in mind? LMZ30606 is good but at 6A it doesn't quite get there.
This regulator would be taking 5V down to 0.85V.

Kind regards,
Dan