74LS251

DM74LS251 3-STATE 1-of-8 Line Data Selector/Multiplexer August 1986 Revised March 2000 DM74LS251 3-STATE 1-of-8 Line Data Selector/Multiplexer General Description These data selectors/multiplexers contain full on-chip binary decoding to select one-of-eight data sources, and feature a strobe-controlled 3-STATE output. The strobe must be at a low logic level to enable these devices. The 3STATE outputs permit direct connection to a common bus. When the strobe input is HIGH, both outputs are in a highimpedance state in which both the upper and lower transistors of each totem-pole output are OFF, and the output neither drives nor loads the bus significantly. When the strobe is LOW, the outputs are activated and operate as standard TTL totem-pole outputs. To minimize the possibility that two outputs will attempt to take a common bus to opposite logic levels, the output control circuitry is designed so that the average output disable time is shorter than the average output enable time. Features s 3-STATE version of DM74LS151 s Interface directly with system bus s Perform parallel-to-serial conversion s Permit multiplexing from N-lines to one line s Complementary outputs provide true and inverted data s Maximum number of common outputs: 129 s Typical propagation delay time (D to Y): 17 ns s Typical power dissipation: 35 mW Ordering Code: Order Number DM74LS251M DM74LS251N Package Number M16A N16E Package Description 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0...