# Various Small capacitors' markings?

Wikipedia explains the basics about the markings of capacitors, here. It lacks many markings most of which confuses me:

Ceramic brown-yellowish cap

• 104 K5K (small ) --- what is the end "5K"? (Cannot be 5 kelvin as operating temperature!?)
• 10 (box box, perpendicular right upermost corner) 35+ (Tantalum Cap, bigger variant of the last one
• 154 C1K (what is C1K, some other notation to Wikipedia?)

Orange Ceramic

• 333 K5X (what is 5X? X roman numeral?)

Brown Circle Slit

• 10n (no other marking, what is the op.temp?) (Diameter: 7.5mm)
• 27J 100V (what is 27J?) (Diameter: 4.9mm, blackdot on the head)

Blue Slit Square

• (triangle) 104K X7R50 (What is triangle? X7R50? Operating V?) (side = 4.9mm)
• 104 (side = 2.6mm, op.V? Tolerance?)

1. How to know operating V without its explicit marking?
2. What do the symbols, such as squares, plus-sign and triangle, mean?
3. Can you evaluate the operating voltage from the size of the capacitor in the case when no marking or poor marking is given?

Generally there are two labels on most caps.

The first is the value, which is written:
<Digit><Digit><Exponential Notation>

The second is the TempCo, or Temperature Coefficient. There are two common specification systems, namely EIA Class 1 and Class 2. This is the mysterious second label in most cases. It's generally written:
<Letter><Number><Letter> (though there are a few variations)
There are a few common tempcos - NP0/C0G, X7R, X5R, Y5V, Z5U

Tantalums, and bigger ceramics often also have the voltages:
<voltage number><+ or v>

Therefore:

• 104 K5K (small )
The value is 10e4, or 100,000 pf / 0.1 uF. The tempco is not standard, may be manufacturer specific/extended range.

• 10 (box box, perpendicular right upermost corner) 35+ (Tantalum Cap, bigger variant of the last one)
Need a picture to be more specific, it's very likely a 35v rated cap, from the 35+.

• 154 C1K (what is C1K, some other notation to Wikipedia?)
Capacitance is 15e4, or 150,000 pf / 0.15 uF. Looks to be a Class 1 dielectric from the C1K. Is this a large cap? the tempco is very good.

• Orange Ceramic 333 K5X (what is 5X? X roman numeral?)
33e3, or 33,000 pf / 33 nF. Tempco is either manufacturer specific, or incorrectly read.

• Brown Circle Slit 10n (no other marking, what is the op.temp?) (Diameter: 7.5mm)
10n very likely means 10 nf, or 10,000 pf. If it's ceramic, it's probably 50v. Likely a cheap part, if the voltage is not marked.

• 27J 100V (what is 27J?) (Diameter: 4.9mm, blackdot on the head)
Voltage rating is self evident. J is the multiplier, and I think there is a standard for letter multipliers, but I do not remember where to find it.

• Blue Slit Square (triangle) 104K X7R50 (What is triangle? X7R50? Operating V?) (side = 4.9mm)
10e4 is the value - 100,000 pf / 0.1uF Tempco is X7R. the 50 is likely the voltage rating.

• 104 (side = 2.6mm, op.V? Tolerance?)
10e4 - 100,000 pf / 0.1uF. Voltage is not known

This is kind of a guess. Anyways, it should show how this sort of thing works. Older parts may vary wildly, and it's always just a guideline. The best thing to do is find the cap's actual datasheet.

A lot of the parts have unusual tempcos. Is this a automotive/extreme duty part which contains these components?

The "K5K", "K5X", "C1K" that doesn't match a temperature characteristic (X7R, NPO, C0G, etc.) is a manufacturer-dependent part marking to make use of the limited space available on the part.

If you look at some of the major manufacturers' datasheets for radial-lead ceramic capacitors, you'll see the following. Capacitance tolerance codes seem to be consistent, but otherwise there is some disparity.

• Murata:
• First character = capacitance tolerance (C = +/-0.25pF, D = +/-0.5pF, J = +/-5%, K = +/-10%, M = +/-20%, Z = +80%/-20%)
• Second character = voltage rating (2 = 25VDC, 5 = 50VDC, 1 = 100VDC, 4 = 250VDC, 9 = 450VDC, 7 = 630VDC)
• Third character = temperature characteristics (A = C0G, C = X7S/X7R, F = F/F5V, 8 = X8G/X8L, 7 = X7T)
• AVX:

• First character = temperature characteristics (A = C0G, C = X7R, D = X5R, E = Z5U, F = X8R, )
• Second character = voltage rating (Z = 10VDC, 5 = 50VDC, 1 = 100VDC, 2 = 200VDC, 9 = 300VDC, 8 = 400VDC, 7 = 500VDC)
• Third character = capacitance tolerance (C = +/-0.25pF, D = +/-0.5pF, F = +/- 1%, G = +/-2%, J = +/-5%, K = +/-10%, M = +/-20%, Z = +80%/-20%)
• KEMET: unclear, first character is sometimes a "K" for KEMET; they use the same capacitance tolerance codes as AVX, but seem to mark with the full text of the voltage rating and temperature characteristics where possible.

Here's a staring point. If you know the type of capacitor that you have, but not what the value is, have a look at (for example) Farnell website and search for that part type. Then you can get a data sheet which usually explains things nicely.

• Could you please post real links! Jun 8, 2010 at 19:24