the aip74hc/hct257 is a quad 2-input multiplexer with 3-state outputs. inputs include clamp diodes. this enables the use of current limiting resistors to interface inputs to voltages in excess of vcc.
for aip74hc257: cmos level
for aip74hct257: ttl level
non-inverting data path
3-state outputs interface directly with system bus
specified from -40℃ to 105℃
packaging information: dip16/sop16/tssop16