SEMICONDUCTOR
1
Features
• Common Select Inputs
• Separate Enable Inputs
• Buffered inputs and Outputs
• Fanout (Over Temperature Range)
- Standard Outputs . . . . . . . . . . . . . . . 10 LSTTL Loads
- Bus Driver Outputs . . . . . . . . . . . . . 15 LSTTL Loads
• Wide Operating Temperature Range . . . -55
o
C to 125
o
C
• Balanced Propagation Delay and Transition Times
• Significant Power Reduction Compared to LSTTL
Logic ICs
• HC Types
- 2V to 6V Operation
- High Noise Immunity: N
IL
= 30%, N
IH
= 30%of V
CC
at
V
CC
= 5V
• HCT Types
- 4.5V to 5.5V Operation
- Direct LSTTL Input Logic Compatibility,
V
IL
= 0.8V (Max), V
IH
= 2V (Min)
- CMOS Input Compatibility, I
l
≤ 1µA at V
OL
, V
OH
Pinout
CD74HC157, CD74HCT157, CD74HC158, CD74HCT158
(PDIP, SOIC)
TOP VIEW
Description
The Harris CD74HC157, CD74HCT157, CD74HC158 and
CD74HCT158 are quad 2-input multiplexers which select
four bits of data from two sources under the control of a
common Select input (S). The Enable input (E) is active Low.
When (E) is High, all of the outputs in the 158, the inverting
type, (1Y-4Y) are forced High and in the 157, the non-
inverting type, all of the outputs (1Y-4Y) are forced Low,
regardless of all other input conditions.
Moving data from two groups of registers to four common
output busses is a common use of these devices. The state
of the Select input determines the particular register from
which the data comes. They can also be used as function
generators.
14
15
16
9
13
12
11
10
1
2
3
4
5
7
6
8
S
1I
0
1I
1
1Y
2I
0
2I
1
GND
2Y
V
CC
4I
0
4I
1
4Y
3I
0
3I
1
3Y
E
Ordering Information
PART NUMBER TEMP. RANGE (
o
C) PACKAGE
PKG.
NO.
CD74HC157E -55 to 125 16 Ld PDIP E16.3
CD74HCT157E -55 to 125 16 Ld PDIP E16.3
CD74HC158E -55 to 125 16 Ld PDIP E16.3
CD74HCT158E -55 to 125 16 Ld PDIP E16.3
CD74HC157M -55 to 125 16 Ld SOIC M16.15
CD74HCT157M -55 to 125 16 Ld SOIC M16.15
CD74HC158M -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 or 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.
September 1997
CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.
Copyright © Harris Corporation 1997
File Number 1642.2
CD74HC157, CD74HCT157,
CD74HC158, CD74HCT158
High Speed CMOS Logic
Quad 2-Input Multiplexers