Confusing polarity marking on SMD tantalum capacitor

Thread Starter

Eketorp

Joined May 20, 2019
9
Hi,

I ordered a couple of Vishay TR3A105K035C4000 tantalum SMD capacitors. The polarity indicating band on one side of the cap has a minus sign. Is it still + side?

See attached picture.

Thanks in advance,
Erik
 

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jpanhalt

Joined Jan 18, 2008
9,762
That part number appears to be a VISHAY part and the polarity is typical for tantalums. That is, the polarity band is the positive (+) end.

If it is not Vishay, please give us the full part number, or better yet, you can look up the datasheet.
 

ericgibbs

Joined Jan 29, 2010
10,205
Hi,
There is no 'printed' minus bar' only two white squares, which I would say, comparing your image with the Vishay d/s is a Positive indicator.
If they intended it to be the Minus polarity, I would say the would have 'printed' a White Minus sign.

E
 

jpanhalt

Joined Jan 18, 2008
9,762
For more information, check Wikipedia on electrolytic capacitors (https://en.wikipedia.org/wiki/Electrolytic_capacitor ).

According to Wiki, electrolytics with a solid electrolyte have the polarity stripe on the positive end. That includes almost all tantalums and SOLID aluminum capacitors. There seems to be some variation depending on form factor, so it is wise always to consult the datasheet if you are unfamiliar with a particular device.
 

SLK001

Joined Nov 29, 2011
1,548
Ok, thanks to everyone who replied to the thread. I feel more confident to put them into the circuit now.
Well, look at it this way... If you put them in backwards, you'll soon know, because Tantalum caps have a very low tolerance for reversing the polarity and will BLOW UP!
 
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