HD74HC257 Datasheet, PDF (1/9 Pages) Hitachi Semiconductor – Quad. 2-to-1-line Data Selectors/Multiplexers(with noninverted 3-state outputs)

HD74HC257
Quad. 2-to-1-line Data Selectors/Multiplexers
(with noninverted 3-state outputs)
Description
The large output drive capability coupled with the 3-state feature make this device ideal for interfacing with
bus lines in a bus organized system. When the output control input line is taken high, the outputs of all four
multiplexers are sent into a high impedance state. When the output control line is low, the select input
chooses whether the A or B input is used.
Features
• High Speed Operation: t_pd (Data to Y) = 10.5 ns typ (C_L = 50 pF)
• High Output Current: Fanout of 15 LSTTL Loads
• Wide Operating Voltage: V_CC = 2 to 6 V
• Low Input Current: 1 µA max
• Low Quiescent Supply Current: I_CC (static) = 4 µA max (Ta = 25°C)
Function Table
Inputs
Output Control Select
A
B
L
L
L
X
L
L
H
X
L
H
X
L
L
H
X
H
H
X
X
X
Notes H: high level, L: low level, X: irrelevant
Outputs
Y
L
H
L
H
High impedance