Electronics > Beginners

Linear regulator output capacitors - ceramic, electrolytic, ?

<< < (3/3)

mariush:
In some *1117 regulator datasheets, you'll find that they say that the ESR of the capacitor must be within 0.1 ohm to 1 ohm. I guess higher ESR would not be as much problem as too low ESR.

In some older datasheets, they specifically say "tantalum" because few such capacitors had ESR below 0.1 ohm. Otherwise, I suspect they don't mention it because they just assumed you'd use a tantalum (and the example schematic would often mention a tantalum capacitor part) or regular electrolytic capacitor, and back then fewer series of capacitors had such low ESR at low capacitance values.

I'm aware of at least one situation where a 1117 regulator was unstable with a ceramic capacitor on the output but I don't remember exactly who was .. it may have been a board bunnie from bunniestudios had mentioned in a blog years ago.  Anyway, here's a eevblog forum thread with a 1117 related problem: https://www.eevblog.com/forum/beginners/ldo-regulator-oscillation/

Ah ... just looked at the bottom of that thread, it wasn't bunnie, it was the guys from mightyohm : https://mightyohm.com/blog/2013/02/simple-fix-for-bus-pirate-power-supply-oscillations/
That board uses a Micrel MIC5025 part.

Navigation

[0] Message Index

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod