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ISO7731: Input and Output Filter (glitch)

Genius 3485 points

Part Number: ISO7731


We have used ISO1050 and ISO7241M in older projects. There we had to apply RC low pass filter at the inputs of the isolator due to possible glitch (please see slla284 page 6).
Now we want to use ISO7731D in a new design. Are there any information or application about the need of such RC filter at the inputs for this device?
Any information that covers all the isolators family for this topic? (like "for this and this family or device you need this or that"). I'm aware of the slla284a document. But ISO77xx family is missing (page 7).

Clarification on this "glitch" topic is highly appreciated.

Thanks and best regards,

  • Hi Patrick,

    Since ISO7731 operates for datarate upto 100Mbps, a glitch filter cannot be introduced as it will limit datarate & increase propagation delay of ISO7731. Hence RC filters at inputs may be required based on the application's input noise levels. Please do note that, ISO7731 is one of our latest digital isolators with On/Off Keying architecture which will be immune to external noise.

    Devices from ISO77xx family meet most digital isolator application's requirements hence I recommend using ISO7731 for your application as well. Thanks

    Koteshwar Rao