C0083C0078C0053C0052C0072C0067C0050C0053C0049C0044 C0083C0078C0055C0052C0072C0067C0050C0053C0049
C0068C0065C0084C0065 C0083C0069C0076C0069C0067C0084C0079C0082C0083C0047C0077C0085C0076C0084C0073C0080C0076C0069C0088C0069C0082C0083
C0087C0073C0084C0072 C0051C0262C0083C0084C0065C0084C0069 C0079C0085C0084C0080C0085C0084C0083
SCLS132E − DECEMBER 1982 − REVISED SEPTEMBER 2003
1POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
C0068 3-State Version of ’HC151
C0068 Wide Operating Voltage Range of 2 V to 6 V
C0068 High-Current 3-State Outputs Interface
Directly With System Bus or Can Drive Up
To 15 LSTTL Loads
C0068 Low Power Consumption, 80-µA Max I
CC
C0068 Typical t
pd
= 9 ns
C0068 ±6-mA Output Drive at 5 V
C0068 Low Input Current of 1 µA Max
C0068 Perform Parallel-to-Serial Conversion
C0068 Complementary Outputs Provide True and
Inverted Data
description/ordering information
These data selectors/multiplexers contain full
binary decoding to select 1-of-8 data sources and
feature strobe-controlled complementary 3-state
outputs.
The 3-state outputs can interface with and drive
data lines of bus-organized systems. With all but
one of the common outputs disabled (in the
high-impedance state), the low impedance of the
single enabled output drives the bus line to a high
or low logic level. Both outputs are controlled by
the output-enable (OE) input. The outputs are
disabled when OE is high.
ORDERING INFORMATION
T
A
PACKAGE
†
ORDERABLE
PART NUMBER
TOP-SIDE
MARKING
PDIP − N Tube of 25 SN74HC251N SN74HC251N
Tube of 40 SN74HC251D
SOIC − D
Reel of 2500 SN74HC251DR
HC251
Reel of 250 SN74HC251DT
−40°C to 85°C
SOP − NS Reel of 2000 SN74HC251NSR HC251
SSOP − DB Reel of 2000 SN74HC251DBR HC251
Tube of 90 SN74HC251PW
TSSOP − PW
Reel of 2000 SN74HC251PWR
HC251
Reel of 250 SN74HC251PWT
CDIP − J Tube of 25 SNJ54HC251J SNJ54HC251J
−55°C to 125°C CFP − W Tube of 150 SNJ54HC251W SNJ54HC251W
LCCC − FK Tube of 55 SNJ54HC251FK SNJ54HC251FK
†
Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are
available at www.ti.com/sc/package.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
SN54HC251 ...J OR W PACKAGE
SN74HC251 . . . D, DB, N, NS, OR PW PACKAGE
(TOP VIEW)
3212019
910111213
4
5
6
7
8
18
17
16
15
14
D5
D6
NC
D7
A
D1
D0
NC
Y
W
SN54HC251 . . . FK PACKAGE
(TOP VIEW)
D2 D3 NC
C B
D4
OE
GND
NC
V
CC
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
D3
D2
D1
D0
Y
W
OE
GND
V
CC
D4
D5
D6
D7
A
B
C
NC − No internal connection
Copyright  2003, Texas Instruments IncorporatedC0080C0082C0079C0068C0085C0067C0084C0073C0079C0078 C0068C0065C0084C0065 C0105C0110C0102C0111C0114C0109C0097C0116C0105C0111C0110 C0105C0115 C0099C0117C0114C0114C0101C0110C0116 C0097C0115 C0111C0102 C0112C0117C0098C0108C0105C0099C0097C0116C0105C0111C0110 C0100C0097C0116C0101C0046
C0080C0114C0111C0100C0117C0099C0116C0115 C0099C0111C0110C0102C0111C0114C0109 C0116C0111 C0115C0112C0101C0099C0105C0102C0105C0099C0097C0116C0105C0111C0110C0115 C0112C0101C0114 C0116C0104C0101 C0116C0101C0114C0109C0115 C0111C0102 C0084C0101C0120C0097C0115 C0073C0110C0115C0116C0114C0117C0109C0101C0110C0116C0115
C0115C0116C0097C0110C0100C0097C0114C0100 C0119C0097C0114C0114C0097C0110C0116C0121C0046 C0080C0114C0111C0100C0117C0099C0116C0105C0111C0110 C0112C0114C0111C0099C0101C0115C0115C0105C0110C0103 C0100C0111C0101C0115 C0110C0111C0116 C0110C0101C0099C0101C0115C0115C0097C0114C0105C0108C0121 C0105C0110C0099C0108C0117C0100C0101
C0116C0101C0115C0116C0105C0110C0103 C0111C0102 C0097C0108C0108 C0112C0097C0114C0097C0109C0101C0116C0101C0114C0115C0046
C0079C0110 C0112C0114C0111C0100C0117C0099C0116C0115 C0099C0111C0109C0112C0108C0105C0097C0110C0116 C0116C0111 C0077C0073C0076C0262C0080C0082C0070C0262C0051C0056C0053C0051C0053C0044 C0097C0108C0108 C0112C0097C0114C0097C0109C0101C0116C0101C0114C0115 C0097C0114C0101 C0116C0101C0115C0116C0101C0100
C0117C0110C0108C0101C0115C0115 C0111C0116C0104C0101C0114C0119C0105C0115C0101 C0110C0111C0116C0101C0100C0046 C0079C0110 C0097C0108C0108 C0111C0116C0104C0101C0114 C0112C0114C0111C0100C0117C0099C0116C0115C0044 C0112C0114C0111C0100C0117C0099C0116C0105C0111C0110
C0112C0114C0111C0099C0101C0115C0115C0105C0110C0103 C0100C0111C0101C0115 C0110C0111C0116 C0110C0101C0099C0101C0115C0115C0097C0114C0105C0108C0121 C0105C0110C0099C0108C0117C0100C0101 C0116C0101C0115C0116C0105C0110C0103 C0111C0102 C0097C0108C0108 C0112C0097C0114C0097C0109C0101C0116C0101C0114C0115C0046