M54/M74HCT257

M54/M74HCT258

February 1993

HCT258 QUAD 2 CHANNEL MULTIPLEXER (3-STATE, INVERTING)

HCT257 QUAD 2 CHANNEL MULTIPLEXER (3-STATE)

B1R

(Plastic Package)

ORDER CODES :

M54HCTXXXF1R

M74HCTXXXM1R

M74HCTXXXB1R

M74HCTXXXC1R

F1R

(Ceramic Package)

M1R

(Micro Package)

C1R

(Chip Carrier)

PIN CONNECTIONS (top view)

.

HIGH SPEED

.

LOW POWER DISSIPATION

.

COMPATIBLE WITH TTL OUTPUTS

.

OUTPUT DRIVE CAPABILITY

15 LSTTL LOADS

.

SYMMETRICAL OUTPUT IMPEDANCE

.

BALANCED PROPAGATION DELAYS

.

PIN AND FUNCTION COMPATIBLE

WITH 54/74LS257/258

DESCRIPTION

The M54/74HCT257 and the M54/74HCT258 are

high speed CMOS MULTIPLEXERs fabricated with

silicon gate C

They have the same high speed performance of

LSTTL combined with true CMOS low power con-

sumption.

These IC’s are composed of an independent 2-

channel multiplexer with common SELECT and EN-

ABLE INPUT.

The M54/74HCT258 is an inverting multiplexer

while the M54/74HCT257 is a non-inverting multi-

plexer. When the ENABLE INPUT is held ”High”,

outputs of both IC’s become high-impedance state.

If SELECT INPUT is held ”Low”, ”A” data is selected,

when SELECT INPUT is high ”H”, ”B” data is

chosen.

All inputs are equipped with protection circuits

against static discharge and transient excess volt-

age.

This integrated circuit has input and output charac-

teristics that are fully compatible with 54/74 LSTTL

logic families. M54/74HCT devices are designed to

directly interface HSC

NMOS components. They are also plug in replace-

HCT257

HCT258

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