MC74AC257/74ACT257 is a quad 2-input multiplexer with 3-state outputs. It selects four bits of data from two sources under control of a Common Data Select (S) input.
The document describes the MC74AC257 and MC74ACT257, which are quad 2-input multiplexers featuring 3-state outputs. These devices allow four bits of data from two sources to be selected using a common data select input, presenting the selected data in true (noninverted) form. The outputs can be switched to a high impedance state by placing a logic HIGH on the common Output Enable (OE) input, enabling direct interfacing with bus-oriented systems. The datasheet covers both AC and ACT series variants.
| Number of Channels | Quad (4) |
|---|---|
| Output Type | 3-State |
| Output Current (Source/Sink) | 24 mA |
| Operating Temperature Range | -40 to +85 °C |
| Package Type (AC Series) | Plastic DIP (NS) |
| Package Type (ACT Series) | Plastic SOIC (DS) |
The device selects four bits of data from two sources under control of a Common Data Select input.
When the Output Enable input is HIGH, the outputs are forced to a high impedance state.