Q regarding Tantalum "dipped" caps

[lgreen]

The application note calls for "solid" tantalum caps, but all I have are "dipped" tantalum caps. Are they the same? Are "dipped" just dipped into some kind of resin?

[Centauri]

Same thing. Recommend DON'T use them - notoriously unreliable. In most cases standard electrolytic will work fine, but may take up a little more space physically.

Cheers

[dhaen]

I can't agree that tant's (dipped or otherwise) are unreliable. I have thousands out in the field, used as power supply decoupling, and the only failures I've had have been due to my own stupidity; reverse polarity or wrong voltage. Of these phenomena, they are much more sensitive than electrolytics. However when used properly they don't seem to deteriorate with time, as electrolytics do.
Avoid use in any application where even a slight reverse bias is possible, and they'll give you good service.
Subsequently I have moved on to other kinds of capacitors, not because I believe they sound better, but the "urban bias" against tant's, both from golden ears and humanitarian protagonists.

[DRC]

Tant's are very relable, especially compared to small value electrolytics. I regularly see then still working in 20/25 year old equipment - plenty of electrolytics will have failed by then.

I have heard tale of them 'erupting' with a small possibility of starting a fire if used in proximity to something flamable (as can a resistor). Best to take the same precautions as used with electrolytics when working on live equipment.

Dave

[JOE DIRT®]

tantulum caps are far superior in my mind than electrolytics (lower ESR)....the .47-1 uf are good for decoupling power supplies

[pinkmouse]

Originally posted by lgreen
Are "dipped" just dipped into some kind of resin?

Yes

[Centauri]

Originally posted by dhaen
I can't agree that tant's (dipped or otherwise) are unreliable. I have thousands out in the field, used as power supply decoupling, and the only failures I've had have been due to my own stupidity

I service pro audio gear, and a lot of it back in the '80s used tantalums for power supply decoupling, and MANY times I have seen these things short out the power rails - I haven't used them since......

Cheers

[Jax]

I have many years of experience with tantalums in digital circuits. They are very reliable under the right circumstances.

But, never ever exceed their maximum ripple current capacity.

If you use them in a low impedance circuit like decoupling after a regulator, use tantalums with a voltage rating at least 3 times the operating voltage. Never ever exceed 0.5V reverse bias.

Their failure mechanic is nasty, often a melted ball of tantalum rolls around in your circuit when they fail.