There is a three digit code printed on a ceramic capacitor
specifying its value. The first two digits are the two significant
figures and the third digit is a base 10 multiplier. The value is given
in picofarads (pF). A letter suffix indicates the tolerance
C
0.25pF
M
20%
D
0.5pF
P
+100 -0%
J
5%
Y
-20 +50%
K
10%
Z
-20 + 80%
Example: a label of "104K" indicates 10104 pF = 100,000 pF = 100 nF = 0.1uF (aka 0.mF) 10%
There is also an EIA three character code that indicates temperature
coefficient. For non-temperature-compensating capacitor, the code
consists of three letters. The first character is a letter that gives
the low-end operating temperature. The second is a digit gives the
high-end operating temperature. The final letter gives capacitance
change over that temperature range:
Letter (low temp)
Digit (high temp)
Letter (change)
X= -55C (-67F)
2= +45C (+113F)
D= 3.3%
Y= -30C (-22F)
4= +65C (+149F)
E= 4.7%
Z= +10C (+50F)
5= +85C (+185F)
F= 7.5%
-
6=+105C (+221F)
P= 10%
-
7=+125C (+257F)
R= 15%
-
-
S= 22%
-
-
T= +22 to -33%
-
-
U= +22 to -56%
-
-
V= +22 to -82%
For instance, a Z5U capacitor will operate from +10C to +85C with
a capacitance change of at most +22% to -56%. An X7R capacitor will
operate from -55C to +125C with a capacitance change of at most 15%.
Temperature-compensated capacitors use a different EIA code. Here,
the first letter gives the significant figure of the change in
capacitance over temperature in ppm/C. The second character gives the
multiplier. The third character gives the maximum error from that in
PPM/C. All ratings are from 25-85C:
Significant Figure
Multiplier
Tolerance
C: 0.0
0: -1
G: 30
B: 0.3
1: -10
H: 60
L: 0.8
2: -100
J: 120
A: 0.9
3: -1000
K: 250
M: 1.0
4: +1
L: 500
P: 1.5
6: +10
M: 1000
R: 2.2
7: +100
N: 2500
S: 3.3
8: +1000
-
T: 4.7
-
-
V: 5.6
-
-
U: 7.5
-
-
For instance, a C0G will have 0 drift, with an error of 30PPM/C,
while a P3K will have -1500PPM/C drift, with a maximum error of
250PPM/C.
Note that in addition to the EIA capacitor codes, there are industry capacitor codes and military capacitor codes.
