OPA2188

Daniel,

The OPA2188 has diode clamps across the input terminals. See this link for a discussion of how this can affect use as a comparator...

Op Amps used as Comparators—is it okay?

These clamps will behave as a diodes with a series resistance of approximately 1k-ohm. If you limit the differential input voltage to a few hundred millivolts, it could be used as a comparator and you probably would not notice the clamps. If you have enough differential voltage to really turn on the clamp diodes, expect that pretty high currents could flow. I suggest that the differential input voltage should be limited to 5V or less at which point you would have several milliamps of input bias current.

Regards, Bruce.