1

Data sheet acquired from Harris Semiconductor

SCHS248

Features

• CD74AC257, CD74ACT257 . . . . Non-Inverting Outputs

• CD74ACT258 . . . . . . . . . . . . . . . . . . . Inverting Outputs

• Buffered Inputs

• Typical Propagation Delay

• Exceeds 2kV ESD Protection MIL-STD-883, Method

3015

• SCR-Latchup-Resistant CMOS Process and Circuit

Design

• Speed of Bipolar FAST™/AS/S with Significantly

Reduced Power Consumption

• Balanced Propagation Delays

• AC Types Feature 1.5V to 5.5V Operation and

Balanced Noise Immunity at 30% of the Supply

•

±24mA Output Drive Current

- Fanout to 15 FAST™ ICs

Drives 50

Ω Transmission Lines

Pinout

CD74AC257, CD74ACT257, CD74ACT258

(PDIP, SOIC)

TOP VIEW

Description

The CD74AC257, CD74ACT257 and CD74ACT258 are

quad 2-input multiplexers with three-state outputs that utilize

the Harris Advanced CMOS Logic technology. Each of these

devices selects four bits of data from two sources under the

control of a common Select input (S). The Output Enable

(OE) is active LOW. When OE is HIGH, all of the outputs (Y

or Y) are in the high-impedance state regardless of all other

input conditions.

Moving data from two groups of registers to four common

output buses is a common use of the CD74AC257,

CD74ACT257 and CD74ACT258. The state of the Select

input determines the particular register from which the data

comes. The CD74AC257, CD74ACT257 and CD74ACT258

can also be used as function generators.

14

15

16

9

13

12

11

10

1

2

3

4

5

7

6

8

S

1Y

GND

2Y

4Y

3Y

OE

AC/ACT257

ACT258

ACT258

AC/ACT257

4Y

3Y

OE

S

1Y

GND

2Y

Ordering Information

PART

NUMBER

TEMP.

PACKAGE

PKG.

NO.

CD74AC257E

-55 to 125

16 Ld PDIP

E16.3

CD74ACT257E

-55 to 125

16 Ld PDIP

E16.3

CD74ACT258E

-55 to 125

16 Ld PDIP

E16.3

CD74AC257M

-55 to 125

16 Ld SOIC

M16.15

CD74ACT257M

-55 to 125

16 Ld SOIC

M16.15

CD74ACT258M

-55 to 125

16 Ld SOIC

M16.15

NOTES:

1. When ordering, use the entire part number. Add the suffix 96 to

obtain the variant in the tape and reel.

2. Wafer and die for this part number is available which meets all elec-

trical specifications. Please contact your local sales office or Harris

customer service for ordering information.

August 1998

CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.

FAST™ is a Trademark of Fairchild Semiconductor.

Copyright

CD74AC257, CD74ACT257,

CD74ACT258

Quad 2-Input Multiplexer

with Three-State Outputs

File Number

1955.1