Capacitor on the adjust pin LM338

[ebijma]

Hello everybody,

Im still working on my own Regulated Valve Bufferd Non Inverted Gainclone.
Im designing a pcb with the regulators for the valve and the regulators for the Lm 3875 and the LM 3875 them selfs on it.
Difficult ? Yes, very.
But i was wondering how much voltage does the capacitor on the adjust pin of the LM 338 need to be?
And the diode on the adjust pin what kind of diode goes there?
The diode that goes from the output to the input what kind goes there?
The mounting holes in the pcb need to be a certain distance apart.
So when i know what kind of components go there i can design a correct pcb.

Hope someone can and will help with my questions.

[Nuuk]

Have a look here .

I suggest that all caps are rated for at least your rail voltage (before the regulators).

[SY]

Nuuk, your link points to a file on your hard drive.

[carlosfm]

Originally posted by SY
Nuuk, your link points to a file on your hard drive.

It points to a file on Nuuk's hard disk, but it tries to find it on mine.

[ebijma]

Originally posted by Nuuk
Have a look here .

I suggest that all caps are rated for at least your rail voltage (before the regulators).

Hello Nuuk,

The link doesn't work.
I can't imaging the capacitor needs to be rail voltage.
But i understand that it would be the savest way to put in a cap that can handle the rail voltage.

Here's a preview of my pcb design.
It's not finished jet.
Im using 4 pentium II coolers with the pcb in the middle.

Thanks for the reply.

[carlosfm]

ebijma, voltage on the Cadj cap is Vout-1.25V, so tipically, to give it some safety margin, you need a 50V cap if you are regulating at around 30V.

[Nuuk]

Sorry, try this .

Yes, I was just giving a safe figure for the cap voltage ratings.