SLVS875C January 2009 – November 2014 TPS54332
The enable threshold voltage is 1.25 V typical. With EN held below that voltage the device is disabled and switching is inhibited even if VIN is above its UVLO threshold. The IC quiescent current is reduced in this state. If the EN voltage is increased above the threshold while VIN is above its UVLO threshold, the device becomes active. Switching is enabled, and the slow-start sequence is initiated.