jremington:
Please explain the real purpose of this circuit. "crude input protection" does not make sense.
So I need to measure a heck of a current. Therefore I have a hall sensor which gives me an output referenced to its own ground (as seen in the PDF earlier). The potential on that output pin will range from -5V to +5V according to the current (-300A min, +300A max).
Testing this with different voltage sources with different polarities gives me the correct values. So if there is something wrong with this circuit, can you tell me what?