The 74LVC1GX04 is a crystal driver. Inputs can be driven from either 3.3 V or 5 V devices. This feature allows the use of these devices as translators in mixed 3.3 V and 5 V environments. This device is fully specified for partial power down applications using IOFF. The IOFF circuitry disables the Y output, preventing the potentially damaging backflow current through the device when it is powered down.