The SN74HC257N is a 2-line to 1-line quadruple Data Selector/Multiplexer with 3-state outputs. It is designed to multiplex signals from 4-bit data sources to 4-output data lines in bus-organized systems. The 3-state outputs do not load the data lines when the OE (G\\) input is at a high logic level. To ensure the high-impedance state during power up or power down, G\ should be tied to VCC through a pull-up resistor, the minimum value of the resistor is determined by the current-sinking capability of the driver.
High-current inverting outputs drive up to 15 LSTTL loads
Provides bus interface from multiple sources in high-performance systems