DESCRIPTION
The M54HC257 is an high speed CMOS QUAD 2 CHANNEL MULTIPLEXER (3-STATE) fabricated with silicon gate C2MOS technology.
This IC is composed of an independent 2-channel multiplexer with common SELECT and ENABLE (OE) input.
The M74HC257 is a non-inverting multiplexer. When the ENABLE input is held "High", outputs of the IC become in a High-Impedance state. If SELECT input is held low, "A" data is selected, when SELECT is high, "B" data is chosen.
All inputs are equipped with protection circuits against static discharge and transient excess voltage.

■ HIGH SPEED: tPD = 11 ns (TYP.) at VCC = 6V
■ LOW POWER DISSIPATION: ICC = 4µA(MAX.) at TA = 25°C
■ HIGH NOISE IMMUNITY: VNIH = VNIL = 28% VCC (MIN.)
■ SYMMETRICAL OUTPUT IMPEDANCE: |IOH| = IOL = 6mA (MIN)
■ BALANCED PROPAGATION DELAYS: tPLH ≅ tPHL
■ WIDE OPERATING VOLTAGE RANGE: VCC (OPR) = 2V to 6V
■ PIN AND FUNCTION COMPATIBLE WITH 54 SERIES 257
■ SPACE GRADE-1: ESA SCC QUALIFIED
■ 50 krad QUALIFIED, 100 krad AVAILABLE ON REQUEST
■ NO SEL UNDER HIGH LET HEAVY IONS IRRADIATION
■ DEVICE FULLY COMPLIANT WITH SCC-9408-047