Dual 2-to-4 line decoder/demultiplexer with Schmitt-trigger inputs

The 74HCS139 decodes two binary weighted address inputs (nA0, nA1) to four mutually exclusive outputs (nY0 to nY3). Each decoder features an enable input (nE). When nE is HIGH all outputs are forced HIGH. The enable input can be used as the data input for a 1-to-4 demultiplexer application. Inputs include clamp diodes. This enables the use of current limiting resistors to interface inputs to voltages in excess of VCC.

All inputs are Schmitt-trigger inputs, capable of transforming slowly changing input signals into sharply defined, jitter-free output signals.