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ISO7841: Increased test voltage of component

Victor Karlsson
Prodigy 80 points
Part Number: ISO7841
Other Parts Discussed in Thread: ISO7842

Hi!

I see that the TI ISO7841 is UL 1577 certified for a test voltage of 5700 Vrms, we have a system with the following requirements: 

Isolation voltage: >= 5760 Vrms

Working voltage: > 1 kVDC

Clearance/creepage: >= 11 mm

Temp: -40°C till +70°C

Is it possible to increase the test voltage to 5760 Vrms? And why are there different test voltages between DIN V VDE (8000 Vpk 60s) and UL (5700 Vrms 60s)? 

Br,

Victor

  • 0
    TI__Genius 17100 points

    Hi Victor,

    Welcome to the E2E forums! TI's digital isolators are certified to meet various test standards, and each standard has its own test and rating requirements, including margin for isolation ratings. Context for isolation tests can be found on the TI White Paper below:




    The ISO7841DWW seems to easily meet working voltage and creepage/clearance requirements, and depending on how the necessary 5760Vrms isolation rating is defined, this device is expected to meet that requirement as well.

    Can you please share how the 5760Vrms voltage will be tested?


    Thank you for your time,
    Manuel Chavez

  • 0 in reply to Manuel Chavez
    Prodigy 80 points

    Hi Manuel, 

    Thank you for your quick answer! 

    It will be tested according to EN 61010-1, 1 minute V r.m.s. for reinforced insulation. Is that a sufficient answer? 

    Br,

    Victor

  • 0 in reply to Victor Karlsson
    TI__Genius 17100 points

    Hi Victor,

    Thank you! Yes, although ISO7842 is certified to 5700Vrms for 60 seconds per EN 61010-1, it is designed with plenty of margin and expected to pass a 60 second test at 5760Vrms.

    Referring to the Time Dependent Dielectric Breakdown curve in the ISO7841 datasheet, the isolation capacitor is expected to survive >27.8 hours at 5760Vrms as shown below:




    Thank you for your time,
    Manuel Chavez