# Calculating the leaking current for a tantalum capacitor

I've been looking at these tantalum caps for a coin cell operated BLE device, but I'm a little confused by specified leakage current. The datasheet lists the leakage current at <= 0.003CV uA. With a 470uA cap at 6.0V, my calculated leakage current is 0.003 * 0.000470 * 6.0, which is 0.00000846. The datasheet says that current is in uA.

Is the leakage current really 0.00000846uA? Or is the C (capacitive) value in the equation supposed to be in uF, not F? That would make more sense if the leakage current was 8.46uA, although that seems high for a "low leakage" cap.

And yes, I am well aware of the potential dangers of tantalums. Operating voltage is going to be in the 3.0V - 2.0V range. We have a few other (highly experienced) EEs working on this project, and I'm trying to get up the learning curve on some aspects of datasheet specs.

• For double checking if some values make sense, you can always measure. Jul 15, 2016 at 13:33
• @PlasmaHH Unfortunately, I don't have tantalum caps nearby to try out. Good point, though. Jul 15, 2016 at 13:36
• Try another supplier of similar device to see what they say. Jul 15, 2016 at 13:38
• My 0.02, I would assume the same thing as you, they ment either C in uF or really 0.003CV in A. Jul 15, 2016 at 13:39
• A few uA of leakage for a tantalum cap seems realistic. Tantalum have relatively high leakage. Ceramic would have much less, but of course, you can't have such a high capacitance value with ceramic. By the way, are you sure you need such a high capacitance somewhere in a battery-operated device? Seems strange to me.
– dim
Jul 15, 2016 at 14:10