DM74S240 • DM74S241 • DM74S244 Octal 3-STATE Buffer/Line Driver/Line Receiver
August 1986
Revised May 2000
DM74S240 • DM74S241 • DM74S244
Octal 3-STATE Buffer/Line Driver/Line Receiver
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 driv-
ers, 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 out-
puts, and can be used to drive terminated lines down to
133Ω.
Features
s
3-STATE outputs drive bus lines directly
s
PNP inputs reduce DC loading on bus lines
s
Hysteresis at data inputs improves noise margins
s
Typical I
OL
(sink current)
s
Typical I
OH
(source current)
Inverting
Noninverting
4.5 ns
6 ns
64 mA
−15
mA
s
Typical propagation delay times
s
Typical enable/disable times 9 ns
s
Typical power dissipation (enabled)
Inverting
Noninverting
450 mW
538 mW
Ordering Code:
Order Number
DM74S240N
DM74S241N
DM74S244N
Package Number
N20A
N20A
N20A
Package Description
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Connection Diagrams
DM74S240N
DM74S241N
DM74S244N
© 2000 Fairchild Semiconductor Corporation
DS006478
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DM74S240 • DM74S241 • DM74S244
Absolute Maximum Ratings
(Note 1)
Supply Voltage
Input Voltage
Operating Free Air Temperature Range
Storage Temperature Range
7V
5.5V
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 tables 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
A
Supply Voltage
HIGH Level Input Voltage
LOW Level Input Voltage
HIGH Level Output Current
LOW Level Output Current
Free Air Operating Temperature
0
Parameter
Min
4.75
2
0.8
−15
64
70
Typ
5
Max
5.25
Units
V
V
V
mA
mA
°C
Electrical Characteristics
over recommended operating free-air temperature range (unless otherwise noted)
Symbol
V
I
H
ys
V
OH
Parameter
Input Clamp Voltage
Hysteresis (V
T+
−
V
T−
)
(Data Inputs Only)
HIGH Level
Output Voltage
V
CC
=
4.75V, V
IH
=
2V
V
IL
=
0.8V, I
OH
= −1
mA
V
CC
=
Min, V
IH
=
2V
V
IL
=
0.8V, I
OH
= −3
mA
V
CC
=
Min, V
IH
=
2V
V
IL
=
0.5V, I
OH
=
Max
V
OL
I
OZH
I
OZL
I
I
I
IH
I
IL
I
OS
I
CC
LOW Level
Output Voltage
Off-State Output Current,
HIGH Level Voltage Applied
Off-State Output Current,
LOW Level Voltage Applied
Input Current at Maximum
Input Voltage
HIGH Level Input Current
LOW Level Input Current
Short Circuit Output Current
Supply
Current
Outputs LOW
Outputs Disabled
Note 2:
All typical values are at V
CC
=
5V, T
A
=
25°C.
Note 3:
Not more than one output should be shorted at a time and duration should not exceed one second.
Conditions
V
CC
=
Min, I
I
= −18
mA
V
CC
=
Min
Min
Typ
(Note 2)
0.4
Max
−1.2
Units
V
V
0.2
2.7
2.4
2
0.55
50
−50
1
50
Any A
Any G
−50
DM74S240
DM74S241, DM74244
DM74S240
DM74S241, DM74244
DM74S240
DM74S241, DM74S244
80
95
100
120
100
120
−400
−2
−225
135
160
150
180
150
180
mA
V
µA
µA
mA
µA
µA
mA
mA
3.4
V
V
CC
=
Min
I
OL
=
Max
V
IL
=
0.8V, V
IH
=
2V
V
CC
=
Max V
O
=
2.4V
V
IL
=
0.8V
V
IH
=
2V
V
O
=
0.5V
V
CC
=
Max V
I
=
5.5V
V
CC
=
Max V
I
=
2.7V
V
CC
=
Max V
I
=
0.5V
V
CC
=
Max (Note 3)
Outputs HIGH
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DM74S240 • DM74S241 • DM74S244
Switching Characteristics
V
CC
=
5V, T
A
=
25°C
Symbol
t
PLH
t
PHL
t
PZL
t
PZH
t
PLZ
t
PHZ
t
PLH
t
PHL
t
PZL
t
PZH
Parameter
Propagation Delay Time
LOW-to-HIGH Level Output
Propagation Delay Time
HIGH-to-LOW Level Output
Output Enable Time to
LOW Level
Output Enable Time to
HIGH Level
Output Disable Time
from Low Level
Output Disable Time
from High Level
Propagation Delay Time
LOW-to-HIGH Level Output
Propagation Delay Time
HIGH-to-LOW Level Output
Output Enable Time to
LOW Level
Output Enable Time to
HIGH Level
C
L
=
45 pF
R
L
=
90Ω
C
L
=
45 pF
R
L
=
90Ω
C
L
=
45 pF
R
L
=
90Ω
C
L
=
45 pF
R
L
=
90Ω
C
L
=
5 pF
R
L
=
90Ω
C
L
=
5 pF
R
L
=
90Ω
C
L
=
150 pF
R
L
=
90Ω
C
L
=
150 pF
R
L
=
90Ω
C
L
=
150 pF
R
L
=
90Ω
C
L
=
150 pF
R
L
=
90Ω
Conditions
DM74S240
DM74S241, DM74244
DM74S240
DM74S241, DM74244
DM74S240
DM74S241, DM74244
DM74S240
DM74S241, DM74244
DM74S240
DM74S241, DM74244
DM74S240
DM74S241, DM74244
DM74S240
DM74S241, DM74244
DM74S240
DM74S241, DM74244
DM74S240
DM74S241, DM74244
DM74S240
DM74S241, DM74244
Min
2
2
2
2
3
3
2
3
4
2
2
2
3
4
3
4
6
6
4
4
Max
7
9
7
9
15
15
10
12
15
15
9
9
10
12
10
12
21
21
12
15
Units
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
3
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DM74S240 • DM74S241 • DM74S244 Octal 3-STATE Buffer/Line Driver/Line Receiver
Physical Dimensions
inches (millimeters) unless otherwise noted
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Package Number N20A
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.
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
SEMICONDUCTOR 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 with
instructions for use provided in the labeling, can be rea-
sonably expected to result in a significant injury to the
user.
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2. A critical component in any component of a life support
device or system whose failure to perform can be rea-
sonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
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