Capacitor tolerance?

[pseudolobster]

I'm thinking of buying these capacitors for a driver project I'm thinking of: http://cgi.ebay.com/Capacitor-Tanta...oryZ4662QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
...my only concern being it looks like they have a 20% tolerance, which seems pretty high to me.

How important is the value of filter capacitors in laser drivers? If it's off by 20% would it cause any problems with stability? If I were to substitute a different value would it be better to use a higher or lower value? You can't wire them in series to achieve higher capacities can you?

Cheers,

-pseudolobster

 

[phoenix3200]

What're you going to do with 100 of them??

I bought some SMT capacitors recently that weren't tantalum (link) but had a 10% tolerance.  10-20% seems to be the norm - you'll pay a lot more with the more precise you go. You'll probably do okay with a 20% tolerance.

If your goal is to smooth out a signal, a higher capacitance value would probably be better than a lower.  The next jump up would be 22 uF.  And capacitors add when in parallel, not series.

 

[rkcstr]

Precise tolerances aren't really necessary unless you need an exact value or have an absolute minimum capacitance that you need. Just for normal applications where its acting as an output cap or something, 20% will be fine.