Tantalum capacitor burning out

[joetristan]

Hello,
I’m using a 10 µF, 20 V tantalum capacitor as a decoupling capacitor across a 5 V supply. When I power the circuit, the capacitor burns out.

At first, I assumed the tantalum capacitor was defective and replaced it, but the new one burned out as well when the circuit was powered.

I then replaced the tantalum capacitor with a 10 µF, 63 V electrolytic capacitor. This time, the capacitor did not fail after powering the circuit.

I do not understand why the tantalum capacitor burns up?

[stj]

a voltage spike or reverse polarity spike will blow tantalum's
where did you get it? i'v only seen 16v and 25v - 20v sounds strange

[Agent24]

Dumb question but did you put it around the right way? At first glance and without experience, one may assume the tantalum is marked with the stripe denoting the negative lead, like an aluminum electrolytic. But on a tantalum the stripe indicates the positive lead.

What kind of circuit is this in? Is it something (like a switching regulator) that may cause voltage spikes?

I agree with stj, a 20v rating sounds odd. Is this a very old capacitor? I've seen very old dipped tantalums rated at odd voltages. It might have just failed due to old age in that case.

I also wonder, did you get it from some cheap place like Temu? I would not trust the quality of no-brand parts from there in any case.

[stj]

Temu is real?
i thought it was just a CIA project to make china look bad!

[stj]

"Unapproved"?
that's a new low.
i'll be spending more time on eevblog at this rate.

[m1ch43lzm]

Approved your previous post

[Agent24]

Maybe the keyword Temu sets off a spam filter or something?

Just another thought - another issue you can have with cheap unbranded components is a higher chance of polarised parts being marked incorrectly. So possibly the polarity stripe is on the wrong lead!