TL F 6418
DM54LS259DM74LS259
8-Bit
Addressable
Latches
May 1992
DM54LS259 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 multifunc-
tional devices capable of storing single-line data in eight
addressable latches and being a 1-of-8 decoder or demulti-
plexer 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 ad-
dressed latch will follow the data input with all unaddressed
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 eliminate the
possibility of entering erroneous data in the latches the en-
able 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 out-
puts are low and unaffected by the address and data inputs
Features
Y
8-Bit parallel-out storage register performs serial-to-par-
allel conversion with storage
Y
Asynchronous parallel clear
Y
Active high decoder
Y
Enable disable input simplifies expansion
Y
Direct replacement for Fairchild 9334
Y
Expandable for N-bit applications
Y
Four distinct functional modes
Y
Typical propagation delay times
Enable-to-output 18 ns
Data-to-output 16 ns
Address-to-output 21 ns
Clear-to-output 17 ns
Y
Fan-out
I
OL
(sink current)
54LS259 4 mA
74LS259 8 mA
I
OH
(source current)
b
0 4 mA
Y
Typical I
CC
22 mA
Connection Diagram
Dual-In-Line Package
TL F 6418 1
Order Number DM54LS259E DM54LS259J
DM54LS259W DM74LS259M
DM74LS259WM or DM74LS259N
See NS Package Number E20A J16A
M16A M16B N16E or W16A
Function Table
Inputs
Output of
Each
Addressed
Other
Function
Clear
E
Latch
Output
H
L
D
Q
i0
Addressable Latch
H
H
Q
i0
Q
i0
Memory
L
L
D
L
8-Line Demultiplexer
L
H
L
L
Clear
Latch Selection Table
Select Inputs
Latch
C
B
A
Addressed
L
L
L
0
L
L
H
1
L
H
L
2
L
H
H
3
H
L
L
4
H
L
H
5
H
H
L
6
H
H
H
7
H
e
High Level L
e
Low Level
D
e
the Level of the Data Input
Q
i0
e
the Level of Q
i
(i
e
0 1
7 as Appropriate) before the Indicated
Steady-State Input Conditions Were Established
C1995 National Semiconductor Corporation
RRD-B30M105 Printed in U S A
Absolute Maximum Ratings
(Note)
If Military Aerospace specified devices are required
please contact the National Semiconductor Sales
Office Distributors for availability and specifications
Supply Voltage
7V
Input Voltage
7V
Operating Free Air Temperature Range
DM54
b
55 C to
a
125 C
DM74LS
0 C to
a
70 C
Storage Temperature Range
b
65 C to
a
150 C
Note
The ``Absolute Maximum Ratings'' are those values
beyond which the safety of the device cannot be guaran-
teed 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
Parameter
DM54LS259
DM74LS259
Units
Min
Nom
Max
Min
Nom
Max
V
CC
Supply Voltage
4 5
5
5 5
4 75
5
5 25
V
V
IH
High Level Input Voltage
2
2
V
V
IL
Low Level Input Voltage
0 7
0 8
V
I
OH
High Level Output Current
b
0 4
b
0 4
mA
I
OL
Low Level Output Current
4
8
mA
t
W
Pulse Width
Enable
17
15
ns
(Note 7)
Clear
17
15
t
SU
Setup Time
Data
20
u
15
u
ns
(Notes 1 2 3
7)
Select
15
v
15
v
t
H
Hold Time
Data
5
u
2 5
u
ns
(Notes 1 2
7)
Select
0
u
2 5
u
T
A
Free Air Operating Temperature
b
55
125
0
70
C
Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
(Note 4)
V
I
Input Clamp Voltage
V
CC
e
Min I
I
e b
18 mA
b
1 5
V
V
OH
High Level Output
V
CC
e
Min I
OH
e
Max
DM54
2 5
V
Voltage
V
IL
e
Max V
IH
e
Min
DM74
2 7
3 4
V
OL
Low Level Output
V
CC
e
Min I
OL
e
Max
DM54
0 4
Voltage
V
IL
e
Max V
IH
e
Min
DM74
0 35
0 5
V
I
OL
e
4 mA V
CC
e
Min
DM74
0 25
0 4
I
I
Input Current
Max
V
CC
e
Max V
I
e
7V
DM74
0 1
mA
Input Voltage
V
I
e
10V
DM54
I
IH
High Level Input
V
CC
e
Max V
I
e
2 7V
20
m
A
Current
I
IL
Low Level Input
V
CC
e
Max V
I
e
0 4V
b
0 4
Current
mA
Enable
V
CC
e
Max V
I
e
0 4V
b
0 8
I
OS
Short Circuit
V
CC
e
Max
DM54
b
20
b
100
mA
Output Current
(Note 5)
DM74
b
20
b
100
I
CC
Supply Current
V
CC
e
Max (Note 6)
22
36
mA
Note 1
The symbols (
v u
) indicate the edge of the clock pulse used for reference
u
for rising edge
v
for falling edge
Note 2
Setup and hold times are with reference to the enable input
Note 3
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 4
All typicals are at V
CC
e
5V T
A
e
25 C
Note 5
Not more than one output should be shorted at a time and the duration should not exceed one second
Note 6
I
CC
is measured with all inputs at 4 5V and all outputs open
Note 7
T
A
e
25 C and V
CC
e
5V
2
Physical Dimensions
inches (millimeters) (Continued)
16-Lead Ceramic Dual-In-Line Package (J)
Order Number DM54LS259J
NS Package Number J16A
16-Lead Molded Package Small Outline (SO)
Order Number DM74LS259M
NS Package Number M16A
4
Physical Dimensions
inches (millimeters) (Continued)
16-Lead Wide Small Outline Molded Package (M)
Order Number DM74LS259WM
NS Package Number M16B
16-Lead Molded Dual-In-Line Package (N)
Order Number DM74LS259N
NS Package Number N16E
5
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