Wet Tantalum Capacitors
Commercial and Military Established Reliability MIL-PRF-39006 Style
T190 Commercial/T290, CLR90, M39006/30
T191 Commercial/T291, CLR91, M39006/31
T192 Commercial/T292, CLR79, M39006/22
T195 Commercial/T295, CLR81, M39006/25
Including the High-Temperature T197 and T198 Series
F3103A 02/04
INDEX
Performance Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
Outline Drawing & Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Marking & Packaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
T190/T290 (CLR90) MIL-PRF-39006/30 Series Part Number Ratings . . . . . . . . . . . . . . . . . . . . . . . .12-15
T191/T291 (CLR91) MIL-PRF-39006/31 Series Part Number Ratings . . . . . . . . . . . . . . . . . . . . . . . 16-17
T192/T292 (CLR79) MIL-PRF-39006/22 Series Part Number Ratings . . . . . . . . . . . . . . . . . . . . . . . .18-21
T195/T295 (CLR81) MIL-PRF-39006/25 Series Part Number Ratings . . . . . . . . . . . . . . . . . . . . . . . 22-23
T197 Series - High Temperature Wet Tantalum Series Part Number Ratings . . . . . . . . . . . . . . . . . . 24-25
T198 Series - High Temperature Wet Tantalum Series Part Number Ratings . . . . . . . . . . . . . . . . . .26-27
IMPORTANT NOTICE
KEMET Electronics Corporation disclaims all warranties, whether express, implied, or statutory as to
any manner whosoever, including the condition of the equipment, its compatibility with specific require-
ments, its merchantability, or fitness for any particular purpose which extend beyond the description on
the face thereof.
Furthermore, under no circumstances shall KEMET Electronics Corporation be liable for consequen-
tial, special, incidental or indirect damages resulting from the use or handling of this product.
Finally, KEMET Electronics Corporation does not assume any responsibility for the correctness of the
information contained in this catalog. All design characteristics, specifications, tolerances, and the like are
subject to change without notice.
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© KEMET Electronics Corporation, P.O. Box 5928, Greenville, SC 29606 (864) 963-6300
Introduction
KEMET wet tantalum capacitors are identified by
the initial “T”, followed by a “Series” number. T19X des-
ignates commercial product; T29X is military grade in
accordance with Military Specification, MIL-PRF-
39006. For detailed performance characteristics of the
T29X series, please refer to the latest issue of the
Military Specification. MIL-PRF-39006 establishes
1000 hour failure rate levels of 1%, 0.1%, and 0.01%.
T29X series components are available in M, P, and R
failure rates (1.0, 0.1, and 0.01, respectively).
Specific requirements are set forth in the respec-
tive Product Series in this catalog. All Military products
are 100% electrically screened for the parameters
shown in the respective product section. For non-mili-
tary product, all series are 100% screened for leakage,
capacitance and dissipation factor. All Series are
inspected to electrical limits using a minimum .1% AQL
sampling plans, according to the Military Standard MIL-
STD-105, even after 100% testing. This sampling plan,
to the best of KEMET Electronics’ knowledge, meets or
exceeds the generally accepted industry standard for
similar products. KEMET capacitors may also be sup-
plied, with prior agreement, to meet specifications with
requirements differing from those of KEMET catalogs.
These Notes apply generally to all KEMET wet tan-
talum capacitors and illustrate typical performance
under normal application conditions, except where
noted. The intent of these Notes is to provide general-
ized information concerning performance characteris-
tics.
This Series may be affected by absorption of water
on external insulating surfaces. The water film may also
attract a layer of dust from the air increasing the effect.
The most sensitive parameter is leakage current.
3. Polarity
These capacitors are inherently polar devices and
may be permanently damaged or destroyed if connect-
ed with the wrong polarity. The positive terminal is iden-
tified on the capacitor body by a polarity mark and the
capacitor body may include an obvious geometrical
shape. See paragraph 11 for Reverse Voltage capabil-
ities.
4. Operating Environment
Most of the discussion under “Storage Conditions”
will apply also when capacitors are operated within the
applicable electrical ratings described below. The tem-
porary increase in leakage current (at standard condi-
tions) following elevated-temperature exposure is not
observed, however, if the capacitors are operated with
adequate DC voltage applied.
5. Capacitance
Capacitance is measured at 120 Hz and 25°C with
up to 1 volt rms applied. Measured circuits are of high
impedance, however, and under these conditions 1 volt
rms may be applied even to 6 volt capacitors (23%
peak reversal) without a DC dias. DC bias is thus nor-
mally not used, except when rated voltage is below 6
volts and the AC signal level exceeds 0.3 vrms.
However, MIL-PRF-39006 provides for up to 2.2 volts
DC. DC bias is not commonly used at room tempera-
ture, but is more commonly used at elevated tempera-
tures.
DC bias causes a small reduction in capacitance,
up to about 2% when full rated voltage is applied as
bias. DF is also reduced by the presence of DC.
Capacitance changes very little below 1 kHz but
decreases more noticably at higher frequencies. Larger
capacitance values decline more rapidly than small rat-
ings.
Capacitance typically changes with temperature
according to the curve of Figure 1.
1. General Application Class
Wet tantalum capacitors are usually applied in cir-
cuits where the AC component is small compared to
the DC component. Typical uses known to KEMET
Electronics include blocking, by-passing, decoupling,
and filtering. They are also used in timing circuits. If two
of these polar capacitors are connected “back-to-back”
(i.e., negative-to-negative or positive-to-positive), the
pair may be used in AC applications (as a non-polar
device).
2. Storage Conditions
Capacitors may be stored without applied voltage
over the operating temperature range specified in the
catalogs for each Series. The range is from -55 to
+125°C for all Series.
Storage at high temperature may cause a small,
temporary increase in leakage current (measured
under standard conditions), but the original value is
usually restored within a few minutes after application
of rated voltage.
DC leakage current may rise upon exposure to a
combination of high temperature and high humidity, but
is normally restored by voltage conditioning under
standard conditions. The increase will be greater than
that experienced under temperature influence alone
because of conduction through absorbed water.
Figure 1. Typical Effect of Temperature upon
Capacitance
© KEMET Electronics Corporation, P.O. Box 5928, Greenville, SC 29606 (864) 963-6300
3
6. Dissipation Factor (DF
)
DF is measured at 120 Hz and 25°C with up to 1
volt rms applied. Note that, in either operation, peak AC
plus DC bias must not exceed either rated voltage
Measurement circuits are of high impedance, however,
and under these conditions 1 volt rms may be applied
even to 6 volt capacitors (23% peak reversal) without a
DC bias. DC bias is thus normally not used, except
when rated voltage is below 6 volts and the AC signal
level exceeds 0.3 vrms. However, MIL-PRF-39006 pro-
vides for up to 2.2 volts DC. DC bias is not commonly
used at room temperature, but is more commonly used
at elevated temperatures.
Dissipation Factor (DF) is a useful low-frequency
measure of the resistive component in capacitors. It is
the ration of the unavoidable resistance to the capaci-
tive reactance, usually expressed in percent. DF
increases with temperature above +25°C and may also
increase at lower temperatures. Unfortunately, one
general limit for DF cannot be specified for all capaci-
tance/voltage combinations, nor can response to tem-
perature be simply stated. Catalogs for the respective
series list DF limits under various conditions.
Dissipation factor increases with increasing fre-
quency as would be expected from the decreasing
capacitive reactance. DF is not a very useful parame-
ter above about 1 kHz. The DF of larger capacitance
values increases more rapidly than that of smaller rat-
ings.
DC bias causes a small reduction in capacitance,
up to about 2% when full rated voltage is applied, as
bias, DF is also reduced by the presence of DC bias.
Rated voltage may cause a decrease in DF of about
0.2% (e.g., a decrease from 3.6 to 3.4% DF).
DF is defined as ESR and is also referred to occa-
Xc
sionally, as tan d or “loss tangent.” The Quality Factor”,
Q, is the reciprocal of DF (DF is not expressed in per-
cent in this calculation). Another expression, rarely
used is the “power factor,” or ESR. Power factor is
cos
Ø, while DF is
cot
Ø.
Z
DC leakage current (DCL) increases with increasing
temperature according to the typical curve of Figure 2.
Leakage current is measured at a rated voltage
through +85°C and may also be measured at +125°C
with 2/3 of rated voltage applied.
8. Rated Voltage
This term refers to the maximum continuous DC
working voltage permissible at temperatures of +85°C or
below. The lower operating temperature is specified
as -55°C. Operation above +85°C is permissible, with
reduced working voltage. The typical working voltage
reduction is to 2/3 of rated voltage at +125°C.
9. Working Voltage
This is the maximum recommended peak DC oper-
ating voltage for continuous duty at or below 85°C with-
out DC voltage surges or AC ripple superimposed. No
voltage derating is required below 85°C. Capacitors may
be operated to 125°C with working voltage linearly der-
ated to 2/3 of the 85°C rating at 125°C.
Figure 3. Working Voltage Change with Temperature
10. Surge Voltage
Surge Voltage is defined as the maximum voltage
to which the capacitor should be subjected under tran-
sient conditions, including peak AC ripple and all DC
transients.
DC Working
Voltage @ 85°C
Surge Voltage
6
8
10
15
25
30
50
60
75 100 125
7. DC Leakage (DCL)
DC leakage is affected by voltage to a much larger
extent, and this effect can frequently be used to advan-
tage in circuits where only very low leakage currents
can be tolerated.
6.9 9.2 11.5 17.2 28.8 34.5 57.5 69 86.2 115 144
Table 1. Surge Voltage Ratings
A typical surge voltage test is performed at +85°C
with the applicable surge voltage per Table 1. The
surge voltage is applied for 1000 cycles of 30 seconds
on voltage through a 1000 ± 100 ohm series resistor
and 30 seconds off voltage with the capacitor dis-
charged through a 1,000 ohm resistor. Upon complet-
ing the test, the capacitors are allowed to stabilize at
room temperature. Capacitance, DF, and DCL are then
tested:
1. The DCL should not exceed the initial 25°C limit.
2. The capacitance should be within ±2% of initial
value.
Figure 2. Typical Effect of Temperature upon DC
Leakage Current
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© KEMET Electronics Corporation, P.O. Box 5928, Greenville, SC 29606 (864) 963-6300
3. The DF should not exceed the initial 25°C limit.
4. Capacitors show no visible mechanical damage
or leakage of electrolyte.
11. Reverse Voltage
When subjected to a DC potential of 3 volts,
applied in the reverse polarity direction for 125 hours ±
10 hours, capacitors shall meet the following require-
ments.
- DC Leakage: shall not exceed 1.25 times initial
limit
- Capacitance: shall be within stated tolerance
(K- ±10%, M- ±20%, J- ±5%)
- Dissipation Factor: shall not exceed initial limit
12. Equivalent Series Resistance (ESR)
Equivalent Series Resistance (ESR) is the pre-
ferred high-frequency statement of the resistance
unavoidably appearing in these capacitors. ESR
decreases with increasing frequency. Typical ESR lim-
its are established in each specific product series.
However, the ESR limits provided are for reference
only, and are not necessarily the actual value that a
particular Series product will attain.
Total impedance of the capacitor is the vector sum
of capacitive reactance (X
c
) and ESR, below reso-
nance; above resonance total impedance is the vector
sum of inductive reactance (X
L
) and ESR. See Figure 4.
Figure 5. The Real Capacitor
A capacitor is a complex impedance consisting of
many series and parallel elements, each adding to the
complexity of the measurement system.
ESL
– Represents lead wire and construction
inductance. In most instances (especially in
tantalum and monolithic ceramic capacitors) it is
insignificant at the basic measurement frequen-
cies of 120 and 1000 Hz.
ESR
– Represents the actual ohmic series resist-
ance in series with the capacitance. Lead wires
and capacitor electrodes are contributing sources.
RL
– Capacitor Leakage Resistance. Typically it
can reach 50,000 megohms in a tantalum capaci-
tor. It can exceed 10
12
ohms in monolithic ceram-
ics and in film capacitors.
Rd
– The dielectric loss contributed by dielectric
absorption and molecular polarization. It becomes
very significant in high frequency measurements
and applications. Its value varies with frequency.
Cd
– The inherent dielectric absorption of the
solid tantalum capacitor which typically equates to
1-2% of the applied voltage.
As frequency increases, X
c
continues to decrease
according to its equation above. There is unavoidable
inductance as well as resistance in all capacitors, and
at some point in frequency, the reactance ceases to be
capacitive and becomes inductive. This frequency is
called the self-resonant point. In wet tantalum capaci-
tors, the resonance is damped by the ESR, and a
smooth, rather than abrupt, transition from capacitive to
inductive reactance (XL = 2πfL) follows.
Despite the fact that the reactance is nearly all
inductive above the self-resonance, these capacitors
find use as decoupling devices up to 10MHz.
ESR and Z are also affected by temperature. At
100 kHz, ESR decreases with increasing temperature.
The amount of change is influenced by the size of the
capacitance and is generally more pronounced on
smaller ratings.
Xc=
1ohm
2πfC
where:
f = frequency, Hertz
C = capacitance, Farad
Figure 4a: Total Impedance of the Capacitor Below Resonance
X
L
= 2πfL
where:
f = frequency, Hertz
C = capacitance, Farad
Figure 4b: Total Impedance of the Capacitor Above Resonance
To understand the many elements of a capacitor, see
Figure 5.
© KEMET Electronics Corporation, P.O. Box 5928, Greenville, SC 29606 (864) 963-6300
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