DM74ALS257N

DM74ALS257, DM74ALS258 3-STATE Quad 1-of-2-Line Data Selector/Multiplexer May 2007 DM74ALS257, DM74ALS258 tm 3-STATE Quad 1-of-2-Line Data Selector/Multiplexer Features General Description Switching specifications at 50pF These data selectors/multiplexers contain inverters and drivers to supply full on-chip data selection to the four Switching specifications guaranteed over full 3-STATE outputs that can interface directly with data temperature and V range CC lines of bus-organized systems. A 4-bit word selected Advanced oxide-isolated, ion-implanted Schottky TTL from one of two sources is routed to the four outputs. process The DM74ALS257 presents true data whereas the Functionally and pin for pin compatible with Schottky DM74ALS258 presents inverted data to minimize propa- and low power Schottky TTL counterpart gation delay time. Improved AC performance over Schottky and low This 3-STATE output feature means that n-bit (paral- power Schottky counterparts leled) data selectors with up to 258 sources can be 3-STATE buffer-type outputs drive bus lines directly implemented for data buses. It also permits the use of Expand any data input point standard TTL registers for data retention throughout the Multiplex dual data buses system. General four functions of two variables (one variable is common) Source programmable counters Ordering Information Package Order Number Number Package Description DM74ALS257M M16A 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow DM74ALS257SJ M16D 16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide DM74ALS258M M16A 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow Devices also available in Tape and Reel. Specify by appending the suffix letter X to the ordering number. 1984 Fairchild Semiconductor Corporation www.fairchildsemi.com DM74ALS257, DM74ALS258 Rev. 1.2DM74ALS257, DM74ALS258 3-STATE Quad 1-of-2-Line Data Selector/Multiplexer Connection Diagram Function Table Inputs Output Y Output Control Select A B DM74ALS257 DM74ALS258 HX X X Z Z LL L X L H LL H X H L LH X L L H LH X H H L H = HIGH Level L = LOW Level X = Don t Care Z = High Impedance (OFF) 1984 Fairchild Semiconductor Corporation www.fairchildsemi.com DM74ALS257, DM74ALS258 Rev. 1.2 2