HD74LS251
HD74LS251 is 1 of 8 Data Selector/Multiplexer manufactured by Renesas.
features a strobe-controlled 3-state output.
The strobe must be at a low logic level to enable this device. The 3-state outputs permit a number of outputs to be connected to a mon bus.
When the strobe input is high, both outputs are in a high-impedance 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 mon 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
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