We are using a AD8277 Unity-Gain Difference Amplifier and noticed that some parts spontaneous break down which results in a short on their power pins. I suspect this happens when a ungrounded device is connected to the inputs. This device floats due the leak in the power supply at 50Hz 70Vpeak.
I would think the internal 40k resistors in combination with the ESD diodes would protect the inputs against this voltage. Could it be that the maximum input current is reached?
Supply voltage AD8277 dual 12V.