CD54HC257, CD74HC257,
CD54HCT257, CD74HCT257
Data sheet acquired from Harris Semiconductor
SCHS171D
November 1997 - Revised October 2003
High-Speed CMOS Logic Quad 2-Input
Multiplexer with Three-State Non-Inverting Outputs
all other input conditions.
Moving data from two groups of registers to four common
output buses is a common use of the 257. The state of the
Select input determines the particular register from which
the data comes. It can also be used as a function generator.
Features
鈥?Buffered Inputs
[ /Title
(CD74
HC257
,
CD74
HCT25
7)
/Sub-
ject
(High
Speed
CMOS
Logic
Quad
2-Input
Multi-
plexer
鈥?Typical Propagation Delay ( In to Output ) = 12ns at
V
CC
= 5V, C
L
= 15pF, T
A
= 25
o
C
鈥?Fanout (Over Temperature Range)
- Standard Outputs . . . . . . . . . . . . . . . 10 LSTTL Loads
- Bus Driver Outputs . . . . . . . . . . . . . 15 LSTTL Loads
鈥?Wide Operating Temperature Range . . . -55
o
C to 125
o
C
鈥?Balanced Propagation Delay and Transition Times
鈥?Signi铿乧ant Power Reduction Compared to LSTTL
Logic ICs
鈥?HC Types
- 2V to 6V Operation
- High Noise Immunity: N
IL
= 30%, N
IH
= 30% of V
CC
at V
CC
= 5V
鈥?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
鈮?/div>
1碌A at V
OL
, V
OH
Ordering Information
PART NUMBER
CD54HC257F3A
CD54HCT257F3A
CD74HC257E
CD74HC257M
CD74HC257MT
CD74HC257M96
CD74HCT257E
CD74HCT257M
CD74HCT257MT
TEMP. RANGE
(
o
C)
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
PACKAGE
16 Ld CERDIP
16 Ld CERDIP
16 Ld PDIP
16 Ld SOIC
16 Ld SOIC
16 Ld SOIC
16 Ld PDIP
16 Ld SOIC
16 Ld SOIC
16 Ld SOIC
Description
The 鈥橦C257 and 鈥橦CT257 are quad 2-input multiplexers
which select four bits of data from two sources under the
control of a common Select Input (S). The Output Enable
input (OE) is active LOW. When OE is HIGH, all of the out-
puts (1Y-4Y) are in the high impedance state regardless of
CD74HCT257M96
NOTE: When ordering, use the entire part number. The suf铿亁 96
denotes tape and reel. The suf铿亁 T denotes a small-quantity reel of
250.
Pinout
CD54HC257, CD54HCT257
(CERDIP)
CD74HC257, CD74HCT257
(PDIP, SOIC)
TOP VIEW
S 1
1I
0
2
1I
1
3
1Y 4
2I
0
5
2I
1
6
2Y 7
GND 8
16 V
CC
15 OE
14 4I
0
13 4I
1
12 4Y
11 3I
0
10 3I
1
9 3Y
CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures.
Copyright
漏
2003, Texas Instruments Incorporated
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