Cautions and warnings

When using TOPcap capacitors, the following cautions and warnings should be taken into

account:

Polarity

Because polymer 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 (see “General technical information”, section 4.6 and section 4.8 under

www.epcos.com/tantalum_capacitors). To avoid reducing their reliability, this voltage may only

occur for a short time, at most five times for a total 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 + 105

°C the maximum continuous voltage must be reduced linearly from the full rated

voltage to 4/5 of it (derating at 105

°C). Operation below the maximum continuous voltage has a

positive effect on the capacitor’s life time reliability. The maximum continuous voltage must not be

exceeded (see“Quality and environment”, section 1.11 under

www.epcos.com/tantalum_capacitors).

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/off, 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 (high

charge/discharge current comditions are not allowed above rated voltage). 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 up to 85

°C (4/5 of the rated voltage for 85 °C up to 105 °C).

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. Capacitance generally varies with temperature (at +85

°C up to +20%) and frequency (see “General technical information”, section 5 under

www.epcos.com/tantalum_capacitors).

Polymer chip capacitors

B760

TOPcap - Basic

Page 24 of 26

Please read Important notes and

Cautions and warnings at the end of this document.