10.2.2.4 Shutdown/Enable Feature

The REF34xx-EP references can be switched to a low power shutdown mode when a voltage of 0.5 V or lower is input to the ENABLE pin. Likewise, the reference becomes operational for ENABLE voltages of 1.6 V or higher. During shutdown, the supply current drops to less than 2 µA, useful in applications that are sensitive to power consumption.

If using the shutdown feature, ensure that the ENABLE pin voltage does not fall between 0.5 V and 1.6 V because this causes a large increase in the supply current of the device and may keep the reference from starting up correctly. If not using the shutdown feature, however, the ENABLE pin can simply be tied to the IN pin, and the reference remains operational continuously.