Conductive Polymer Tantalum Solid Capacitors

1.1 Prohibited circuits

Since problems can be expected, POSCAP cannot be used on the following circuits.

(1) High impedance voltage retention circuits

(2) Coupling circuit

(3) Time constant circuits

(4) Circuits greatly affected by leakage current

(5) The circuit in which two or more POSCAP are connected in a series so as to raise the endurance voltage.

1.2 Failure and life-span

The failure rate is 0.5 %* / 1000 h (Confidence level : 60 %) based on JIS C 5003.

The mainly failure modes are as follows.

* B2 size or less : 1.0 %

1.2-1 Contingency failure

The main causes of failure are thermal stresses cause by the soldering or thermal use environment, along with heat

stresses, electrical stresses or mechanical stresses. The most common failure mode is a short circuit.

In case a short circuit occurs, ensure safety by fully considering the followings.

(a) If POSCAP emit smoke, turn off the main power of the equipment. In this case, keep your face and hands away

from the area.

(b) It may take a few seconds to a few minutes before POSCAP emits smoke by the situation. Increase safety by

using a protective circuit.

(c) If the smoke comes into eyes, rinse immediately. If the smoke is inhaled, gargle immediately.

(d) In case a large current continues to flow after a short circuit, in the worst case, the shorted-out section may

ignite. For safety, install a redundant circuit or a protective circuit, etc.

1.2-2 Wear-out failure (lifetime)

When lifetime exceeded the specified guarantee time of Endurance and Damp heat, electrolyte might insulate

and cause electric characteristic changed. This is called an open circuit. The rated capacitance values and

the electrical characteristics values such as ESR specified in the characteristics list are factory default values.

Please carefully design a circuit since rated capacitance values and the electrical characteristics values

may change (increase) beyond the specified values under the conditions of rated voltage/temperature and

electrical/mechanical performances.

1.3 Reduction of failure stress

When POSCAP is used within the rated voltage, it shows a stable characteristic, but it may be damaged in a short

circuit when an overvoltage, for instance, is applied. The time to reach the failure mode can be extended by using

POSCAP with reduced environment temperature, ripple current and applied voltage.

Failure rate

・ In the case of the endurance which is 105 °C 2000 h.

0.5 %/1000 h (Environment temp. : 105 °C, Rated voltage or Category voltage applied)

・ In the case of the endurance which is 105 °C 1000 h or 125 °C 1000 h.

1.0 %/1000 h (Environment temp. : 105 °C, Rated voltage or Category voltage applied)

・ In the case of the endurance which is 85 °C 1000 h.

1.0 %/1000 h (Environment temp. : 85 °C, Rated voltage applied)

1.4 Check the rated performance

After checking the operation and installation environments, design the circuit so that it falls within the rated performance

range stipulated in this delivery specification.

1.5 Operating temperature and ripple current

(1) Set the operating temperature so that it falls within the range stipulated in this delivery specification.

(2) Do not apply current that exceeds the allowable ripple current. Ripple current should be controlled so that

　surface temperature of a capacitor do not exceed the rated temperature.

(For questions regarding TQC series, please contact us.)

(3) The ESR values specified in the characteristics list are factory default values.

ESR values may change (increase) beyond the specified values depending on the customer's use conditions.

14-Jan-22

　　Application Guidelines (POSCAP)

1. Circuit design