1.

General description

The 74HC258 is a high-speed Si-gate CMOS device and is pin compatible with low power

Schottky TTL (LSTTL). The 74HC258 is specified in compliance with JEDEC

standard no. 7A.

The 74HC258 has four identical 2-input multiplexers with 3-state outputs, which select

4 bits of data from two sources and is controlled by a common data select input (S).

The data inputs from source 0 (1I0 to 4I0) are selected when input S is LOW and the data

inputs from source 1 (1I1 to 4I1) are selected when S is HIGH.

Data appears at the outputs (1Yto4Y) in inverted form from the select inputs.

The 74HC258 is the logic implementation of a 4-pole, 2-position switch, where the position

of the switch is determined by the logic levels applied to S. The outputs are forced to a

high-impedance OFF-state when OE is HIGH.

The logic equations for the outputs are:

The 74HC258 is identical to the 74HC257 but has inverting outputs.

2.

Features

74HC258

Quad 2-input multiplexer; 3-state; inverting

Rev. 04 — 14 April 2008

Product data sheet

1Y

OE

1I1

S

×

1I0

S

×

+

()

×

=

2Y

OE

2I1

S

×

2I0

S

×

+

()

×

=

3Y

OE

3I1

S

×

3I0

S

×

+

()

×

=

4Y

OE

4I1

S

×

4I0

S

×

+

()

×

=