© Semiconductor Components Industries, LLC, 2004

September, 2004 − Rev. 2

1

Publication Order Number:

MC74VHCT257A/D

MC74VHCT257A

Quad 2−Channel Multiplexer

with 3−State Outputs

The MC74VHCT257A is an advanced high speed CMOS quad

2−channel multiplexer fabricated with silicon gate CMOS technology.

It achieves high speed operation similar to equivalent Bipolar

Schottky TTL while maintaining CMOS low power dissipation.

It consists of four 2−input digital multiplexers with common select

(S) and enable (OE) inputs. When (OE) is held High, selection of data

is inhibited and all the outputs go Low.

The select decoding determines whether the A or B inputs get routed

to the corresponding Y outputs.

The VHCT inputs are compatible with TTL levels. This device can be

used as a level converter for interfacing 3.3 V to 5.0 V because it has full

5 V CMOS level output swings.

The VHCT257A input structures provide protection when voltages

between 0 V and 5.5 V are applied, regardless of the supply voltage. The

output structures help prevent device destruction caused by supply

voltage—input/output voltage mismatch, battery backup, hot insertion, etc.

The internal circuit is composed of three stages, including a buffered

output which provides high noise immunity and stable output. The inputs

tolerate voltages up to 7 V, allowing the interface of 5 V systems to 3 V

systems.

Figure 1. Pin Assignment

13

14

15

16

9

10

11

12

5

4

3

2

1

8

7

6

S

Y0

B0

A0

Y1

B1

A1

GND

Y3

B3

A3

OE

B2

A2

Y2

SO−16

SO−16

D SUFFIX

CASE 751B

MARKING DIAGRAMS

1

8

9

16

1

8

16

9

VHCT257A

AWLYWW

VHCT257A

ALYW

TSSOP−16

DT SUFFIX

CASE 948F

ORDERING INFORMATION

EIAJ SO−16

M SUFFIX

CASE 966

VHCT257A

ALYW

A

= Assembly Location

L, WL

= Wafer Lot

Y

= Year

W, WW

= Work Week

16

9

1

8

Device

Package

MC74VHCT257AD

SO−16

48 Units/Rail

MC74VHCT257ADT

TSSOP−16

96 Units/Rail

MC74VHCT257AM

EIAJSO−16

50 Units/Rail

MC74VHCT257ADR2

2500 Tape & Reel

MC74VHCT257ADTR2 TSSOP−16 2500 Tape & Reel

MC74VHCT257AMEL

EIAJSO−16 2000 Tape & Reel

†For information on tape and reel specifications,

including part orientation and tape sizes, please

refer to our Tape and Reel Packaging Specification

Brochure, BRD8011/D.

http://onsemi.com