74LS253N
3-STATE version of DM74LS153 with same pinout
Schottky-diode-clamped transistors
Permit multiplexing from N-lines to one line
Performs parallel-to-serial conversion
Strobe/output control
High fanout totem-pole outputs
Typical propagation delay
Data to output 12 ns
Select to output 21 ns
Typical power dissipation 35 mW