Data Sheet

1
Data sheet acquired from Harris Semiconductor
SCHS169C
Features
• Selects One of Eight Binary Data Inputs
• Three-State Output Capability
• True and Complement Outputs
• Typical (Data to Output) Propagation Delay of 14ns at
V
CC
= 5V, C
L
= 15pF, T
A
= 25
o
C
• 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
• Alternate Source is Philips
• 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
CD54HC251, CD54HCT251
(CERDIP)
CD74HC251, CD74HCT251
(PDIP, SOIC)
TOP VIEW
Description
The ’HC251 and ’HCT251 are 8-channel digital multiplexers
with three-state outputs, fabricated with high-speed silicon-
gate CMOS technology. Together with the low power
consumption of standard CMOS integrated circuits, they
possess the ability to drive 10 LSTTL loads. The three-state
feature makes them ideally suited for interfacing with bus
lines in a bus-oriented system.
This multiplexer features both true (Y) and complement (
Y)
outputs as well as an output enable (
OE) input. The OE must
be at a low logic level to enable this device. When the
OE
input is high, both outputs are in the high-impedance state.
When enabled, address information on the data select inputs
determines which data input is routed to the Y and
Y
outputs. The ’HCT251 logic family is speed, function, and
pin-compatible with the standard ’LS251.
14
15
16
9
13
12
11
10
1
2
3
4
5
7
6
8
I
3
I
2
I
1
I
0
Y
Y
GND
OE
V
CC
I
5
I
6
I
7
S0
S1
S2
I
4
Ordering Information
PART NUMBER
TEMP. RANGE
(
o
C) PACKAGE
CD54HC251F3A -55 to 125 16 Ld CERDIP
CD54HCT251F3A -55 to 125 16 Ld CERDIP
CD74HC251E -55 to 125 16 Ld PDIP
CD74HC251M -55 to 125 16 Ld SOIC
CD74HC251MT -55 to 125 16 Ld SOIC
CD74HC251M96 -55 to 125 16 Ld SOIC
CD74HCT251E -55 to 125 16 Ld PDIP
CD74HCT251M -55 to 125 16 Ld SOIC
CD74HCT251MT -55 to 125 16 Ld SOIC
CD74HCT251M96 -55 to 125 16 Ld SOIC
NOTE: When ordering, use the entire part number. The suffix 96
denotes tape and reel. The suffix T denotes a small-quantity reel of
250.
November 1997 - Revised October 2003
CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.
Copyright
© 2003, Texas Instruments Incorporated
CD54HC251, CD74HC251,
CD54HCT251, CD74HCT251
High-Speed CMOS Logic
8-Input Multiplexer, Three-State
[
/Title
(
CD74
H
C251
,
C
D74
H
CT25
1
)
/
Sub-
j
ect
(
High
S
peed
C
MOS
L
ogic
8
-Input
M
ulti-
p
lexer;
T
hree-