Cautions and warnings

General

Some parts of this publication contain statements about the suitability of our ceramic transient

voltage suppressor (CTVS) components (multilayer varistors (MLVs), CeraDiodes, ESD/EMI

filters, SMD disk varistors (CU types), leaded transient voltage/ RFI suppressors (SHCV types))

for certain areas of application, including recommendations about incorporation/design-in of these

products into customer applications. The statements are based on our knowledge of typical

requirements often made of our CTVS devices in the particular areas. We nevertheless expressly

point out that such statements cannot be regarded as binding statements about the suitability of

our CTVS components for a particular customer application. As a rule, EPCOS is either unfamiliar

with individual customer applications or less familiar with them than the customers themselves.

For these reasons, it is always incumbent on the customer to check and decide whether the

CTVS devices with the properties described in the product specification are suitable for use in a

particular customer application.

Do not use EPCOS CTVS components for purposes not identified in our specifications,

application notes and data books.

Ensure the suitability of a CTVS in particular by testing it for reliability during design-in. Always

evaluate a CTVS component under worst-case conditions.

Pay special attention to the reliability of CTVS devices intended for use in safety-critical

applications (e.g. medical equipment, automotive, spacecraft, nuclear power plant).

Design notes

Always connect a CTVS in parallel with the electronic circuit to be protected.

Consider maximum rated power dissipation if a CTVS has insufficient time to cool down

between a number of pulses occurring within a specified isolated time period. Ensure that

electrical characteristics do not degrade.

Consider derating at higher operating temperatures. Choose the highest voltage class

compatible with derating at higher temperatures.

Surge currents beyond specified values will puncture a CTVS. In extreme cases a CTVS will

burst.

If steep surge current edges are to be expected, make sure your design is as low-inductance

as possible.

In some cases the malfunctioning of passive electronic components or failure before the end of

their service life cannot be completely ruled out in the current state of the art, even if they are

operated as specified. In applications requiring a very high level of operational safety and

especially when the malfunction or failure of a passive electronic component could endanger

human life or health (e.g. in accident prevention, life-saving systems, or automotive battery line

applications such as clamp 30), ensure by suitable design of the application or other measures

(e.g. installation of protective circuitry or redundancy) that no injury or damage is sustained by

third parties in the event of such a malfunction or failure. Only use CTVS components from the

automotive series in safety-relevant applications.

SMD disk varistors (CU varistors)

Automotive series

Page 27 of 30

Please read Cautions and warnings and

Important notes at the end of this document.