The ST2149 is a 4-bit dual supply level translator which provides the level shifting capability to allow data transfer in a multi-voltage system. Externally applied voltages, VCC and VL, set the logic levels on either side of the device. Its architecture allows bi-directional level translation without a control pin. The ST2149 accepts VL from 1.65 to 3.6 V and VCC from 1.65 to 5.5 V, making it ideal for data transfer between low-voltage ASICs/PLD and higher voltage systems. This device has a tri-state output mode which can be used to disable all I/Os. The ST2149 supports power-down mode when VCC is grounded/floating or when the device is disabled via the OE pin.