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ISO7741: overvoltage category consult

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Part Number: ISO7741

Hi team,

When I read the ISO7741 datasheet, I cannot understand the overvoltage category spec. Could you please explain what does this spec means?

In the blue circle, how can we get  I-III for the DW-16 package? What do the two numbers I and III mean here? Thanks.


Charles Lin

  • Hi Charles,

    Overvoltage category of a product defines where all it can be installed / used with respect to main supply voltages. i.e., it indicates whether a product can be used at the origin of mains installation (like energy meter requiring Cat IV), at fixed installations with special requirements (like circuit breaker requiring Cat III), in energy-consuming equipment supplied from fixed installation (like appliances requiring Cat II) or in sections requiring low voltages (like protected electronic circuits requiring Cat I).  Based on what category an isolation device supports, it can be used in the above class of products accordingly.

    In quantitative terms, overvoltage category also represents the impulse transient voltage rating of the isolator. Please see below table indicating impulse transient voltage requirement to meet a given overvoltage category. Let me know if you have any questions, thanks.

    Koteshwar Rao