Note that references are to IEC 60950 Third Edition 1999-04. Where the references in the Second Edition differ, they appear in parentheses.
Optocouplers may be used to provide the circuit separation required by IEC 60950. When used in this way they are considered safety critical.
REQUIREMENTSSafety critical components must comply with the relevant safety standard for that component. For European
approvals the relevant standard is EN 60950 or VDE 0884, for the US it is UL1577. You must also ensure that the rated dielectric voltage withstand and the creepage distance between the legs of
the optocoupler are suitable for the level of circuit separation required in your equipment. Even if the optocoupler is approved, it may not be approved to the appropriate level of separation.
DESIGN TIPSThe only practical option is to use an optocoupler which
already has the relevant safety approvals. Make sure the optocoupler has the approvals you need for your target markets (see Submitting a product to a Test House for Approval).
If you plan to submit your product to a Test House, you will probably be required to submit a copy of the safety approval license of the optocoupler together with your
product. The Test House needs the certificate to authenticate the approval and to ensure that you use the optocoupler in accordance with any Conditions of Acceptability which may be specified as part of the
approval. The supplier of your optocoupler should be able to get you a copy of the license.
MANUFACTURERS
You can get information on optocouplers from the following list of manufacturers. Agilent Technologies
ToshibaThe list of manufacturers is given as a service for your convenience. It does not imply i-Spec's recommendation of
any particular manufacturer or component. Manufacturers wishing to be added to this list are requested to
contact us.
REFERENCE
Complete requirements are given in IEC 60950, Clause 2.10 (2.9).
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