The overtemperature and shutdown pin, OTF/SH_DN, is bidirectional and allows both op amps to be put into a low I_Q state (approximately 200 µA per amplifier) when forced low or to less than V_{IL_OTF}. As a result of being bidirectional, and the respective enable and disable functionality, this pin must be pulled high or greater than V_{IH_OTF} through a pullup resistor. The use of a 10-kΩ pullup resistor leads to a drive current of approximately 210 µA when used with a pullup voltage of 3.3 V.

When the junction temperature of the ALM2403-Q1 exceeds the specified limits, OTF/SH_DN goes low to alert the application that both the outputs have turned off because of an overtemperature event.

When OTF/SH_DN is pulled low and the op amps are shut down, the op amps are in an open loop, even when there is negative feedback applied. This occurrence is due to the loss of the open-loop gain in the op amps when the biasing is disabled.