Replace electrolytic caps with tantalum caps

Hi,

I have realized a prototype which uses 3 electrolytic capacitors:

  1. The first is at the output of a DC-DC boost converter (TPS61090RSAR): 100uF

  2. The second is at the input of an ADC converter: 4.7uF

  3. The third is parallel to a LED used in a sensor (suggested by the sensor manufacturer. Likely to make the voltage stable): 220uF

I am designing the PCB using SMD components and I would like to replace the electrolytic capacitors with tantalum capacitors of the same capacity.

As far as I know this should be possible.

Can someone confirm this? Are there precautions?

Thank you in advance.

For my customers, the difference is price. All else works the same.

Paul

Why do you want to use tantalum capacitors?

Maybe worth reading this:

Personally I've never seen a tantalum go bang, whereas I have seen an Al cap burst (but that was stupidity
of mine getting the polarity wrong)... Traditional Al electrolytics don't pose a fire risk though, its a steam
explosion/bursting

I had good sized tantalum capacitor on a breadboard that was rated for something like 8 V, without thinking about it, I changed power supplies and gave it 12 V (which was fine for all the other components) and after a few minutes the thing ignited. It was quite a surprise. Of course the same could be said for an electrolytic popping but the ignition was a bit more disturbing to me. Of course it was down to my own own dumb mistake but I've been a bit more wary of using them since.

Tantalums have better high frequency performance but they cost more. They are commonly used in switching converters I.e. the first listed application. There’s probably no advantage in applications 2 and 3, but they’d work ok.

fab64:
I am designing the PCB using SMD components and I would like to replace the electrolytic capacitors with tantalum capacitors of the same capacity.

tantalum capacitors are a kind of ‘electrolytic’ capacitor anyway, right? But just no liquid runs out of them.

Thank you all.

@polymorph: they are smaller than SMD electrolytic counterparts

@MarkT: very informative reference material

I'll go with the tantalum capacitors double checking the voltage rate and increasing it a little bit more. Just in case. I don't want my customers catch fire!

fab64:
I'll go with the tantalum capacitors double checking the voltage rate and increasing it a little bit more. Just in case. I don't want my customers catch fire!

That is certainly a good idea. Ample voltage safety margins and trusted sources, if you want to sell them.
I recommend that test overvoltage and reversed polarity yourself. They do fail pretty spectacular and I think everyone using them should have seen it live at least one time. Expect something like a tiny firecracker (the ones that come in sheets on a fuse) for smaller capacities. Keep your distance and maybe wear eye protection.