54AC257 Datasheet | National Semiconductor

.. - 54ACT257 Quad 2-Input Multiplexer with TRI-STATE Outputs July 1998 - 54ACT257 Quad 2-Input Multiplexer with TRI-STATE ® Outputs General Description The ’AC/’ACT257 is a quad 2-input multiplexer with TRI-STATE outputs. Four bits of data from two sources can be selected using a mon Data Select input. The four outputs present the selected data in true (noninverted) form. The outputs may be switched to a high impedance state by placing a logic HIGH on the mon Output Enable (OE) input, allowing the outputs to interface directly with bus-oriented systems. Features n n n n n n ICC and IOZ reduced by 50% Multiplexer expansion by tying outputs together Noninverting TRI-STATE outputs Outputs source/sink 24 m A ’ACT257 has TTL-patible inputs Standard Military Drawing (SMD) - ’AC257: 5962-88703 - ’ACT257: 5962-89689 Logic Symbols IEEE/IEC DS100286-1 DS100286-2 Pin Names S OE I0a- I0d I1a- I1d Za- Zd Description mon Data Select Input TRI-STATE Output Enable Input Data Inputs from Source 0 Data Inputs from Source 1 TRI-STATE Multiplexer Outputs TRI-STATE ® is a registered trademark of National Semiconductor Corporation. FACT™ is a trademark of Fairchild Semiconductor Corporation. © 1998 National Semiconductor Corporation DS100286 .national. Connection Diagrams Pin Assignment for DIP and Flatpak Functional Description The ’AC/’ACT257 is quad 2-input multiplexer with TRI-STATE outputs. It selects four bits of data from two sources under control of a mon Data Select input. When the Select input is LOW, the I0x inputs are selected and when Select is HIGH, the I1x inputs are selected. The data on the selected inputs appears at the outputs in true (noninverted) form. The device is the logic implementation of a 4-pole, 2-position switch where the position of the switch is determined by the logic levels supplied to the Select input. The logic equations for the outputs are shown below: Za = OE - (11a - S + I0a - S) Zb...