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FAULT pin in offline flyback

cupoftea

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Hi
On page 21 of the NCP1239 datasheet, they have a resistor in series with the Zener into the FAULT pin. We are purely and only using the FAULT pin for detection of overvoltage on the bias coil. So would you agree, we do not need the series resistor? The capacitor for us, is 10n, and the NTC is just replaced with 22k. As such, we surely don’t need the series resistor, or have a I missed something?

We are using a BZX84-C20, SOT23 zener.

NCP1239 datasheet
 
External series resistor is there to keep Fault pin maximum rating of 5.5 V. If you can keep the limit without the resistor, you don't need it.
 

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