ALUMINUM ORGANIC CAPACITORS
Performance Characteristics
Introduction
4. Voltage Ratings
• 2 - 10 VDC Rated Voltage
KEMET entered the world of aluminum capacitors with
the introduction of the AO-CAP, designated the A700
Series, which has been targeted for power management
applications. The structure of the AO-CAP uses alu-
minum as the anode material, aluminum oxide as the
dielectric, and a conductive organic polymer for its
counter-electrode material. The A700 series is 100%
screened for all electrical parameters: Capacitance @
120Hz, Dissipation Factor (DF) @ 120 Hz, ESR @ 100
kHz, and DC Leakage.
This is the maximum peak DC operating voltage
from -55°C to +125°C for continuous duty.
Surge Voltage Ratings
Surge voltage capability is demonstrated by applica-
tion of 1000 cycles of the relevant voltage at 25°C,
85°C, or 125 °C. The parts are charged through a 33
ohm resistor for 30 seconds and then discharged
through a 33 ohm resistor for 30 seconds for each
cycle.
The AO-CAP offers many advantages including extreme-
ly low ESR, high capacitance retention at high operating
frequencies, no dry-out related failure mechanism and
no voltage de-rating up to125°C.
Voltage Ratings • Table 1
Rated
Voltage
Surge
Voltage
-55°C to 125 °C
ELECTRICAL
1. Operating Temperature Range
• -55°C to +125°C
2V
2.5V
4V
2.6V
3.2V
5.2V
8V
No derating with temperature is required.
6.3V
8V
2. Non-Operating Temperature Range
• -55°C to 125°C
10.4V
13V
10V
3. Capacitance and Tolerance
• 22µF to 470µF
5. Reverse Voltage Rating & Polarity
•
20ꢀ Tolerance
Aluminum polymer capacitors are polar devices and
may be permanently damaged or destroyed if con-
nected in the wrong polarity. The positive terminal is
identified by a laser-marked stripe. These capacitors
will withstand a certain degree of transient voltage
reversal for short periods as shown in the following
table. Please note that these parts may not be oper-
ated continuously in reverse, even within these limits.
Capacitance is measured at 120 Hz, up to 1.0 volt
rms maximum and up to 2.5V DC maximum. DC
bias causes only a small reduction in capacitance,
up to about 2% when full rated voltage is applied.
DC bias is not commonly used for room temperature
measurements but is more commonly used when
measuring at temperature extremes.
Capacitance does decrease with increasing fre-
quency, but not nearly as much or as quickly as
standard tantalums. Figure 1 compares the frequen-
cy induced cap roll-off between the AO-CAP and tra-
ditional MnO2 types. Capacitance also increases
with increasing temperature. See Section 12 for tem-
perature coefficients.
Table 2
Temperature Permissible Transient Reverse Voltage
25°C
55°C
85°C
125°C
60% of Rated Voltage
50% of Rated Voltage
40% of Rated Voltage
30% of Rated Voltage
6. DC Leakage Current
Because of the high conductivity of the polymer, the
AO-CAP family has higher leakage currents than tra-
ditional MnO2 type Tantalum caps. The DC Leakage
limits at 25°C are calculated as 0.06 x C x V, (where
C is cap in µF and V is rated voltage in Volts) for
part types with rated voltage ≤ 4V, and equals 0.04 x
C x V, for voltages > 4V. Limits for all part numbers
are listed in the ratings tables.
Figure 1.
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