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ISO7731-Q1: About ISO7731-Q1 specifiction

Part Number: ISO7731-Q1

Hello Expert.
Thank you for your special support every day.
I have some questions about ISO7731-Q1.
I'd appreciate if you could answer following questions.  

What is the difference of DW and DBQ PKG?
Does both PKG have dual capacitor isolation?
I'd like to ask about the contents 6.6 Insulation Specifications of datasheet page 6.
Specifically, it is an item of the highlight below.
Q1. Could you tell me the test contents about time dependent dielectric breakdown (TDDB)? 
Q2. I understand that the meaning of 1000 VRMS is continuous operating voltage that can guarantee lifetime of over 40 years. Is it right?
Is this ISO77xx-Q1 series used by automotive engine unit?

Best Regars.


  • Hi Noriaki,

    Please find my inputs below, thanks.

    Apart from the package dimension differences, there are no other differences between ISO7731-Q1 in DW package and DBQ package functionally. Only the package related parameters like creepage, clearance and isolation ratings get reduced/affected.
    Yes, the two capacitors in series construction is going to remain the same for both devices.

    The major change between two packages is creepage and clearance. When these two parameters are reduced, the original isolation specs cannot be met with reduced creepage & clearance. Hence the isolation ratings get reduced as indicated in Insulation Specifications table under Section 6.6.
    A2a. You can find the exact test methodology used in the App Note at the link below under Section 4.2.
    A2b. Yes, 1000Vrms stated as working voltage is the continuous operating voltage guaranteeing a lifetime of over 40 years.

    The device can be used for various automotive applications and is already being used by many automotive customers. Their usage in a specific application is generally dependent on the device datasheet specifications meeting customer requirement including temperature rating.

    Koteshwar Rao