The input pins have internal 120Ω series resistors at each terminal and clamped
diodes to each other. These diodes protect the input devices from large
differential input voltages. However, when a differential voltage exceeding
600mV is applied to the amplifier, the clamped diodes conduct current; in this
condition, the differential input resistance falls to 240Ω. It is highly
possible that a significant amount of current would flow through these
protection diodes. Always ensure that the current flowing into the input pins
is limited to the absolute maximum of 10mA.