I'm working on a circuit I have a buffer amplifier with a low value pull-up on the output. I need to protect the op-amp because there could be high voltage on the pull-up pin.
The circuit normally works at 5V but there is a possibility that the output of the op-amp can see up to 15V. The op-amp would get damaged. I can't simply use a diode or other common techniques because this over-voltage could last minutes plus because of the low pull-up on the output, I need very low output impedance. Any suggestions would be appreciated.
What I need is somehow to detect an over-voltage on the op-amp output (I'm thinking of using a zener or comparator) and then disconnect the op-amp circuitry from the output.