Tantalum chip capacitors
Multiple Anode, Ultra-low ESR
Cautions and warnings
B45396R
When using tantalum capacitors with a manganese dioxide coating, the following cautions and
warnings should be taken into account:
Polarity
Because tantalum capacitors are
polar capacitors,
it is important to observe their polarity
markings (positive pole on the anode, negative pole on the cathode). Any incorrect polarity
resulting from the sum of the AC and DC voltage components must be smaller than or equal to
the permitted
polarity reversal voltage.
To avoid reducing their reliability, this
voltage may only
occur for a short time, at most five times for a duration of one minute per hour.
Voltage
The
maximum continuous voltage
depends on the ambient temperature. Within the temperature
range of 55 to +85
°C,
the rated voltage is equal to the maximum continuous voltage. Between
+ 85 and + 125
°C
the maximum continuous voltage must be reduced linearly from the full rated
voltage to 2/3 of it (derating). At 150
°C
(only B4519*P series) the voltage must be reduced to 1/2
and at 175
°C
(only B4519*T series) to 1/3 of the rated voltage. Operation below the maximum
continuous voltage has a positive effect on the capacitor’s failure rate. The maximum continuous
voltage must not be exceeded.
All unfavourable operating conditions (such as possible line overvoltages, unfavourable
tolerances of the transformation ratio of the line transformer in the equipment, repeated
overvoltages when the equipment is switched on, high ambient temperatures) must be taken into
account when determining the
operating voltage.
The
surge voltage
is the maximum voltage (peak value) that may be applied to the capacitor for
short periods, at most five times for a total duration of up to 1 minute per hour. The surge voltage
must not be applied for periodic charging and discharging in the course of normal operation and
cannot be part of the operating voltage. The permissible surge voltage for all capacitors in this
data book is 1.3 x the rated voltage. The occurrence of voltage impulses (transient voltages) that
exceed the surge voltage may lead to irreparable damage.
Capacitance
The actual
capacitance
of a capacitor can deviate from the rated capacitance by as much as the
full magnitude of the tolerance at delivery. The capacitance varies with the temperature (at
+125
°C
+12% up to +20%) and decreases with increasing frequency.
Please read
Important notes
and
Cautions and warnings
at the end of this document.
Page 10 of 12
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