DM74LS259 8-Bit Addressable Latches
August 1986
Revised March 2000
DM74LS259
8-Bit Addressable Latches
General Description
These 8-bit addressable latches are designed for general
purpose storage applications in digital systems. Specific
uses include working registers, serial-holding registers,
and active-high decoders or demultiplexers. They are mul-
tifunctional devices capable of storing single-line data in
eight addressable latches, and being a 1-of-8 decoder or
demultiplexer with active-high outputs.
Four distinct modes of operation are selectable by control-
ling the clear and enable inputs as enumerated in the func-
tion table. In the addressable-latch mode, data at the data-
in terminal is written into the addressed latch. The
addressed latch will follow the data input with all unad-
dressed latches remaining in their previous states. In the
memory mode, all latches remain in their previous states
and are unaffected by the data or address inputs. To elimi-
nate the possibility of entering erroneous data in the
latches, the enable should be held HIGH (inactive) while
the address lines are changing. In the 1-of-8 decoding or
demultiplexing mode, the addressed output will follow the
level of the D input with all other outputs LOW. In the clear
mode, all outputs are LOW and unaffected by the address
and data inputs.
Features
s
8-Bit parallel-out storage register performs serial-to-par-
allel conversion with storage
s
Asynchronous parallel clear
s
Active high decoder
s
Enable/disable input simplifies expansion
s
Direct replacement for Fairchild DM9334
s
Expandable for N-bit applications
s
Four distinct functional modes
s
Typical propagation delay times:
Enable-to-output
Data-to-output
Clear-to-output
s
Fan-out
I
OL
(sink current)
s
Typical I
CC
22 mA
8 mA
I
OH
(source current)
−0.4
mA
18 ns
16 ns
17 ns
Address-to-output 21 ns
Ordering Code:
Order Number
DM74LS259M
DM74LS259WM
DM74LS259N
Package Number
M16A
M16B
N16E
Package Description
16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow
16-Lead Small Outline Intergrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
© 2000 Fairchild Semiconductor Corporation
DS006418
www.fairchildsemi.com
DM74LS259
Absolute Maximum Ratings
(Note 1)
Supply Voltage
Input Voltage
Operating Free Air Temperature Range
Storage Temperature Range
7V
7V
0°C to
+70°C
−65°C
to
+150°C
Note 1:
The “Absolute Maximum Ratings” are those values beyond which
the safety of the device cannot be guaranteed. The device should not be
operated at these limits. The parametric values defined in the “Electrical
Characteristics” table are not guaranteed at the absolute maximum ratings.
The “Recommended Operating Conditions” table will define the conditions
for actual device operation.
Recommended Operating Conditions
Symbol
V
CC
V
IH
V
IL
I
OH
I
OL
t
W
t
SU
t
H
T
A
Supply Voltage
HIGH Level Input Voltage
LOW Level Input Voltage
HIGH Level Output Current
LOW Level Output Current
Pulse Width
(Note 5)
Setup Time
Hold Time
(Note 2)(Note 3)(Note 5)
Free Air Operating Temperature
Enable
Clear
Data
Data
Select
15
15
15↑
15↓
2.5↑
2.5↑
0
70
Parameter
Min
4.75
2
0.8
−0.4
8
Nom
5
Max
5.25
Units
V
V
V
mA
mA
ns
ns
ns
°C
(Note 2)(Note 3)(Note 4)(Note 5) Select
Note 2:
The symbols (↓,
↑)
indicate the edge of the clock pulse used for reference:
↑
for rising edge,
↓
for falling edge.
Note 3:
Setup and hold times are with reference to the enable input.
Note 4:
The select-to-enable setup time is the time before the HIGH-to-LOW enable transition that the select must be stable so that the correct latch is
selected and the others not affected.
Note 5:
T
A
=
25°C and V
CC
=
5V.
Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Symbol
V
I
V
OH
V
OL
Parameter
Input Clamp Voltage
HIGH Level
Output Voltage
LOW Level
Output Voltage
I
I
I
IH
I
IL
I
OS
I
CC
Input Current @ Max
Input Voltage
HIGH Level Input Current
LOW Level Input Current
Enable
Short Circuit Output Current
Supply Current
Conditions
V
CC
=
Min, I
I
= −18
mA
V
CC
=
Min, I
OH
=
Max
V
IL
=
Max, V
IH
=
Min
V
CC
=
Min, I
OL
=
Max
V
IL
=
Max, V
IH
=
Min
I
OL
=
4 mA, V
CC
=
Min
V
CC
=
Max, V
I
=
7V
V
I
=
10V
V
CC
=
Max, V
I
=
2.7V
V
CC
=
Max, V
I
=
0.4V
V
CC
=
Max, V
I
=
0.4V
V
CC
=
Max (Note 7)
V
CC
=
Max (Note 8)
−20
22
2.7
3.4
0.35
0.25
0.5
0.4
0.1
20
−0.4
−0.8
−100
36
mA
µA
mA
mA
mA
Min
Typ
(Note 6)
Max
−1.5
Units
V
V
V
Note 6:
All typicals are at V
CC
=
5V, T
A
=
25°C.
Note 7:
Not more than one output should be shorted at a time, and the duration should not exceed one second.
Note 8:
I
CC
is measured with all inputs at 4.5V, and all outputs OPEN.
3
www.fairchildsemi.com
Creative Market
京公网安备 11010802033920号
EEWORLD
