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DM74LS240, DM74LS241
Octal 3-STATE Buffers/Line Drivers/Line Receivers
General Description
These buffers/line drivers are designed to improve both the
performance and PC board density of 3-STATE buffers/
drivers employed as memory-address drivers, clock drivers,
and bus-oriented transmitters/receivers. Featuring 400 mV
of hysteresis at each low current PNP data line input, they
provide improved noise rejection and high fanout outputs
and can be used to drive terminated lines down to 133Ω.
Features
n 3-STATE outputs drive bus lines directly
n PNP inputs reduce DC loading on bus lines
n Hysteresis at data inputs improves noise margins
Connection Diagrams
n Typical I
n Typical I
n Typical propagation delay times
n Typical enable/disable time 18 ns
n Typical power dissipation (enabled)
(sink current)
OL
54LS 12 mA
74LS 24 mA
(source current)
OH
54LS −12 mA
74LS −15 mA
Inverting 10.5 ns
Noninverting 12 ns
Inverting 130 mW
Noninverting 135 mW
DM74LS240, DM74LS241 Octal 3-STATE Buffers/Line Drivers/Line Receivers
March 1998
Dual-In-Line Package
Order Number DM54LS240J,
DM54LS240W, DM54LS240E,
DM74LS240WM or DM74LS240N
See Package Number E20A, J20A,
M20B, N20A or W20A
DS006411-1
Dual-In-Line Package
DS006411-2
Order Number DM54LS241J,
DM54LS241W, DM54LS241E,
DM74LS241WM or DM74LS241N
See Package Number E20A, J20A,
M20B, N20A or W20A
© 1998 Fairchild Semiconductor Corporation DS006411 www.fairchildsemi.com
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Function Tables
LS240
LS241
Inputs Output
G
AY
LL H
LH L
HX Z
Inputs Outputs
GG
XLLXL
XLHXH
XH X X Z
HX X L L
HX X H H
LX X X Z
=
L
Low Logic Level
H=High Logic Level
X=Either Low or High Logic Level
Z=High Impedance
1A 2A 1Y 2Y
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Absolute Maximum Ratings (Note 1)
Supply Voltage 7V
Input Voltage 7V
DM54LS, 54LS −55˚C to +125˚C
DM74LS 0˚C to +70˚C
Storage Temperature Range −65˚C to +150˚C
Operating Free Air Temperature Range
Recommended Operating Conditions
Symbol Parameter DM54LS240, 241 DM74LS240, 241 Units
Min Nom Max Min Nom Max
V
CC
V
IH
V
IL
I
OH
I
OL
T
A
Note 1:
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.
Supply Voltage 4.5 5 5.5 4.75 5 5.25 V
High Level Input Voltage 2 2 V
Low Level Input Voltage 0.7 0.8 V
High Level Output Current −12 −15 mA
Low Level Output Current 12 24 mA
Free Air Operating Temperature −55 125 0 70 ˚C
The “AbsoluteMaximumRatings” are those values beyond which the safety of the device cannot be guaranteed. The device should not be operated at these
Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Symbol Parameter Conditions Min Typ Max Units
(Note 2)
=
V
HYS Hysteresis (V
Input Clamp Voltage V
I
T+−VT−
)V
CC
CC
Data Inputs Only
V
V
I
I
OZH
OZL
High Level Output Voltage V
OH
Low Level Output Voltage V
OL
Off-State Output Current, V
High Level Voltage Applied V
Off-State Output Current, V
CC
=
V
IL
V
CC
=
V
IL
V
CC
=
V
IL
CC
=
V
IL
=
V
IH
CC
=
IL
=
IH
Low Level Voltage Applied
I
I
I
IH
I
IL
I
OS
I
CC
Input Current at Maximum V
Input Voltage V
High Level Input Current V
Low Level Input Current V
Short Circuit Output Current V
Supply Current V
CC
=
I
CC
CC
CC
CC
Outputs Open Outputs Low LS240 26 44
=
Note 2: All typicals are at V
Note 3: Not more than one output should be shorted at a time, and the duration should not exceed one second.
CC
5V, T
=
25˚C.
A
=
Min, I
−18 mA −1.5 V
I
=
Min 0.2 0.4 V
=
Max, I
=
Max, I
=
0.5V, I
=
Max I
=
Min, V
Min, V
Min, V
Min DM74 2.7
IH
=
−1 mA
OH
=
Min DM54/DM74 2.4 3.4 V
IH
=
−3 mA
OH
=
Min DM54/DM74 2
IH
=
Max
OH
Min I
=
12 mA DM74 0.4
OL
=
Max DM54 0.4 V
OL
Min DM74 0.5
=
Max V
=
2.7V 20 µA
O
Max
Min V
=
Max, V
I
=
0.4V −20 µA
O
=
7V (DM74) 0.1 mA
10V (DM54)
=
=
=
=
=
Max, V
Max, V
2.7V 20 µA
I
=
0.4V −0.2 mA
I
Max (Note 3) −40 −225 mA
Max, Outputs High LS240, LS241 13 23
LS241 27 46 mA
Outputs
LS240 29 50
Disabled
LS241 32 54
3 www.fairchildsemi.com
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Switching Characteristics
=
at V
CC
5V and T
Symbol Parameter Conditions DM54LS DM74LS Units
t
PLH
t
PHL
t
PZL
t
PZH
t
PLZ
t
PHZ
t
PLH
t
PHL
t
PZL
t
PZH
Note 4: 54LS Output load is C
=
25˚C
A
Propagation Delay Time C
Low to High Level Output R
Propagation Delay Time C
High to Low Level Output R
Output Enable Time to C
Low Level R
Output Enable Time to C
High Level R
Output Disable Time C
from Low Level R
Output Disable Time C
from High Level R
Propagation Delay Time C
Low to High Level Output R
Propagation Delay Time C
High to Low Level Output R
Output Enable Time to C
Low Level R
Output Enable Time to C
High Level R
=
L
50 pF for t
PLH,tPHL,tPZL
and t
Max Max
=
45 pF LS240 18 14 ns
L
=
667Ω LS241 18 18
L
=
45 pF LS240 18 18 ns
L
=
667Ω LS241 18 18
L
=
45 pF LS240 30 30 ns
L
=
667Ω LS241 30 30
L
=
45 pF LS240 23 23 ns
L
=
667Ω LS241 23 23
L
=
5 pF LS240 25 25 ns
L
=
667Ω LS241 25 25
L
=
5 pF LS240 18 18 ns
L
=
667Ω LS241 18 18
L
=
150 pF LS240 18 ns
L
=
667Ω LS241 21
L
=
150 pF LS240 22 ns
L
=
667Ω LS241 22
L
=
150 pF LS240 33 ns
L
=
667Ω LS241 33
L
=
150 pF LS240 26 ns
L
=
667Ω LS241 26
L
.
PZH
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Physical Dimensions inches (millimeters) unless otherwise noted
Ceramic Leadless Chip Carrier Package (E)
Order Number DM54LS240E or DM54LS241E
Package Number E20A
5 www.fairchildsemi.com
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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
20-Lead Ceramic Dual-In-Line Package (J)
Order Number DM54LS240J or DM54LS241J
Package Number J20A
20-Lead Wide Small Outline Molded Package (M)
Order Number DM74LS240WM or DM74LS241WM
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Package Number M20B
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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
20-Lead Molded Dual-In-Line Package (N)
Order Number DM74LS240N or DM74LS241N
Package Number N20A
20-Lead Ceramic Flat Package (W)
Order Number DM54LS240W or DM54LS241W
Package Number W20A
7 www.fairchildsemi.com
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LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMI-
DM74LS240, DM74LS241 Octal 3-STATE Buffers/Line Drivers/Line Receivers
CONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into
the body, or (b) support or sustain life, and (c) whose
failure to perform when properly used in accordance
2. A critical component in any component of a life support
device or system whose failure to perform can be reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
with instructions for use provided in the labeling, can
be reasonably expected to result in a significant injury
to the user.
Fairchild Semiconductor
Corporation
Americas
Customer Response Center
Tel: 1-888-522-5372
www.fairchildsemi.com
Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and Fairchild reserves the right at any time without notice to change said circuitry and specifications.
Fairchild Semiconductor
Europe
Fax: +49 (0) 1 80-530 85 86
Email: [email protected]
Deutsch Tel: +49 (0) 8 141-35-0
English Tel: +44 (0) 1 793-85-68-56
Italy Tel: +39 (0) 2 57 5631
Fairchild Semiconductor
Hong Kong Ltd.
13th Floor, Straight Block,
Ocean Centre, 5 Canton Rd.
Tsimshatsui, Kowloon
Hong Kong
Tel: +852 2737-7200
Fax: +852 2314-0061
National Semiconductor
Japan Ltd.
Tel: 81-3-5620-6175
Fax: 81-3-5620-6179
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