This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

ISO7821: What is the difference between t = 60 sec (qualification) and t = 1 sec (100% production)?

Part Number: ISO7821

Dear experts,

My customer want to use ISO7821DW in their product. The maximum working isolation voltage is 2000VDC<2121VDC, so the ISO7821DW could meet the spec.

And they need add the 4000VDC/1min between two sides. I find the withstanding isolation voltage is 5700V*1.414 from datesheet. The ISO7821DW could meet the spec. if only considering the voltage value, but the spec., t = 60 sec (qualification) and t = 1 sec (100% production), misunderstood me, could you tell me the difference between them? And Could the ISO7821DW meet the 4000VDC/1min test? Thanks!



  • Hi Gordon,

    Thanks for reaching out and sharing customer requirements.

    The device meets all the specifications requirements that you have listed out, i.e., working voltage of 2000VDC and 4000VDC for 1 min. Hence, customer can go ahead and consider ISO7821 for their application. I would also recommend them to check for their creepage / clearance requirement and accordingly make sure ISO7821 in DW package meets them. If it doesn't meet them then they could also consider using DWW package that has higher creepage and clearance.

    Regarding your question on qualification and production, the times that are referred as qualification are the times for which device supports those rated voltages. Times referred as production are the times that every individual device gets tested for in the factory production line. i.e., device is rated for 5700Vrms for 60 secs and hence, qualification tests are done for this time duration while testing each individual device for this duration is impractical and hence, 1 second production tests at slightly higher voltages than rated are considered to eliminate any factory defects. This is standard industry practice.

    Let me know if you have any questions, thanks.

    Koteshwar Rao

  • Hi Koteshwar,

    Your explanation is very very clear, thanks for your help!