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MAX22531 input protection (overvoltage, reverse polarity)

Category: Hardware
Product Number: MAX22531

Hello,

currently, we're designing a layout using the MAX22531 isolated ADC.

For that, the maximum 400V AIN_ input on the secondary isolated side is regulated down to the maximum 1.8V Vref of the internal reference of the ADC.

To protect against overvoltage, I though a voltage clamping circuit with zener diodes might work. However, R52 has to be very large to limit current flow in the ADC which may be a problem.

Can someone point me out the correct way to have both overvoltage and reverse voltage protection?

Do I need R52, when I'm adding a fuse between Z2 and GNDA, or will the ADC be damaged before it is triggered?

Thank you!

Best,

Andy