I have a question about "VDE 0884-10 :2006-12".
According to iCoupler datasheets,
I can find VIORM spec, but I just wondered why each parts has a different VIORM voltage just as following.
Even if the same VDE certificate, is there any reasons that VIORM varies on each devices?
And what is beneficial for application's aspect if the VIORM voltage is higher?
Please give me some advice on that.
We will set the Viorm based on the creepage of the part, and the lifetime of the internal insulation so that the numbers generated by the standard are close to the applications that we want to support. We are also supporting applications that are outside of the scope of the VDE standard, such as Basic insulation or DC applications. This can make for a confusing set of values sometimes.
The ADuM3210 has 4mm of creepage, so it does not support high reinforced working voltages due to creepage, and the internal insulation will have ~50 years of life at that voltage so we qualified it as a 560Vac part.
The ADuM2210 has 7.6mm of creepage, that supports up to 767Vpeak reinforced in most system standards. That particular part has thinner insulation, so as a practical matter in the data sheet we limit it to560Vpeak for 60Hz applications. It passes the VDE-0884-10 requirements at he 849V level and that is useful information for people who want to use it for DC applications where the lifetime is longer.
The AD7402 has really thick insulation so we are comfortable rating it for 1250Vpeak, and large packaging, which will support that voltage for basic insulation, so we chose that combination to satisfy the needs of motor drive applications.
Most of our newest parts can be used up to 849Vpeak and the creepage supports that.
Your application needs to determine the working voltage. We choose how we want the agency to test the parts based on the creepage, clearance, insulation lifetime and the target end application. Usually the higher the Viorm the more applications a part can support.