tm
DM74ALS240A, DM74ALS241A Octal 3-STATE Bus Driver
September
2007
©1986 Fairchild Semiconductor Corporation www.fairchildsemi.com
DM74ALS240A, DM74ALS241A Rev. 1.3
DM74ALS240A, DM74ALS241A
Octal 3-STATE Bus Driver
Features
■
Advanced low power oxide-isolated ion-implanted
Schottky TTL process
■
Functional and pin compatible with the DM74LS
counterpart
■
Improved switching performance with less power
dissipation compared with the DM74LS counterpart
■
Switching response specified into 500
Ω
and 50pF
load
■
Switching response specifications guaranteed over
full temperature and V
CC
supply range
■
PNP input design reduces input loading
■
Low level drive current: 74ALS
=
24mA
General Description
These octal 3-STATE bus drivers are designed to
provide the designer with flexibility in implementing a bus
interface with memory, microprocessor, or communi-
cation systems. The output 3-STATE gating control is
organized into two separate groups of four buffers.
The DM74ALS240A control inputs symmetrically enable
the respective outputs when set logic LOW, while the
DM74ALS241A has complementary enable gating.
The 3-STATE circuitry contains a feature that maintains
the buffer outputs in 3-STATE (high impedance state)
during power supply ramp-up or ramp-down. This elimi-
nates bus glitching problems that arise during power-up
and power-down.
Ordering Information
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Connection Diagram
DM74ALS240A DM74ALS241A
Order Number
Package
Number Package Description
DM74ALS240AWM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
DM74ALS240ASJ M20D 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
DM74ALS240AN N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide
DM74ALS241AWM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
DM74ALS240A, DM74ALS241A Octal 3-STATE Bus Driver
©1986 Fairchild Semiconductor Corporation www.fairchildsemi.com
DM74ALS240A, DM74ALS241A Rev. 1.3 2
Function Tables
DM74ALS240A DM74ALS241A
Logic Diagrams
DM74ALS240A DM74ALS241A
Input Output
GAY
LL H
LH L
HX Z
Input Output Input Output
1G 1A Y 2G 2A Y
LL L HL L
LHHHHH
HX Z LX Z
DM74ALS240A, DM74ALS241A Octal 3-STATE Bus Driver
©1986 Fairchild Semiconductor Corporation www.fairchildsemi.com
DM74ALS240A, DM74ALS241A Rev. 1.3 3
Absolute Maximum Ratings
Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be
operable above the recommended operating conditions and stressing the parts to these levels is not recommended.
In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability.
The absolute maximum ratings are stress ratings only.
Recommended Operating Conditions
The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended
operating conditions are specified to ensure optimal performance to the datasheet specifications. Fairchild does not
recommend exceeding them or designing to absolute maximum ratings.
Symbol Parameter Rating
V
CC
Supply Voltage 7V
V
I
Input Voltage 7V
Voltage Applied to Disabled Output 5.5V
T
A
Operating Free Air Temperature Range 0°C to +70°C
T
STG
Storage Temperature Range –65°C to +150°C
θ
JA
Typical Thermal Resistance
N Package
M Package
60.5°C/W
79.8°C/W
Symbol Parameter Min. Typ. Max. Units
V
CC
Supply Voltage 4.5 5 5.5 V
V
IH
HIGH Level Input Voltage 2 V
V
IL
LOW Level Input Voltage 0.8 V
I
OH
HIGH Level Output Current –15 mA
I
OL
LOW Level Output Current 24 mA
T
A
Operating Free Air Temperature 0 70 °C
DM74ALS240A, DM74ALS241A Octal 3-STATE Bus Driver
©1986 Fairchild Semiconductor Corporation www.fairchildsemi.com
DM74ALS240A, DM74ALS241A Rev. 1.3 4
Electrical Characteristics
Over recommended operating free-air temperature range (unless otherwise specified).
Symbol Parameter Conditions Min. Typ. Max. Units
V
IK
Input Clamp Voltage V
CC
=
4.5V, I
I
=
–18mA –1.5 V
V
OH
HIGH Level Output Voltage V
CC
=
4.5V to 5.5V, I
OH
=
–0.4mA V
CC
– 2 V
V
CC
=
4.5V I
OH
=
–3mA 2.4
I
OH
=
Max. 2
V
OL
LOW Level Output Voltage V
CC
=
4.5V, I
OL
=
Max. 0.35 0.5 V
I
I
Input Current at Max. Input
Voltage
V
CC
=
5.5V, V
I
=
7V 0.1 mA
I
IH
HIGH Level Input Current V
CC
=
5.5V, V
I
=
2.7V 20 µA
I
IL
LOW Level Input Current V
CC
=
5.5V, V
IL
=
0.4V –0.1 mA
I
O
Output Drive Current V
CC
=
5.5V, V
O
=
2.25V –30 –112 mA
I
OZH
HIGH Level 3-STATE Output
Current
V
CC
=
5.5V, V
O
=
2.7V 20 µA
I
OZL
LOW Level 3-STATE Output
Current
V
CC
=
5.5V, V
O
=
0.4V –20 µA
I
CC
Supply Current V
CC
=
5.5V, ALS240A, Outputs HIGH 4 10 mA
Outputs LOW 13 23
Outputs 3-STATE 14 25
V
CC
=
5.5V, ALS241A, Outputs HIGH 9 15
Outputs LOW 15 26
Outputs 3-STATE 17 30
DM74ALS240A, DM74ALS241A Octal 3-STATE Bus Driver
©1986 Fairchild Semiconductor Corporation www.fairchildsemi.com
DM74ALS240A, DM74ALS241A Rev. 1.3 5
Switching Characteristics DM74ALS240A
Over recommended operating free air temperature range.
Switching Characteristics DM74ALS241A
Over recommended operating free air temperature range.
Symbol Parameter Conditions
From
(Input)
To
(Output) Min. Max. Units
t
PLH
Propagation Delay Time,
LOW-to-HIGH Level Output
V
CC
=
4.5V to 5.5V,
C
L
=
50pF,
R1
=
500
Ω
,
R2
=
500
Ω
,
T
A
=
Min. to Max.
AY29ns
t
PHL
Propagation Delay Time,
HIGH-to-LOW Level Output
29ns
t
PZH
Output Enable Time to HIGH
Level Output
GY313ns
t
PZL
Output Enable Time to LOW
Level Output
318ns
t
PHZ
Output Disable Time from
HIGH Level Output
GY210ns
t
PLZ
Output Disable Time from
LOW Level Output
312ns
Symbol Parameter Conditions
From
(Input)
To
(Output) Min. Max. Units
t
PLH
Propagation Delay Time,
LOW-to-HIGH Level Output
V
CC
=
4.5V to 5.5V,
C
L
=
50pF,
R1
=
500
Ω
,
R2
=
500
Ω
,
TA = Min. to Max.
AY311ns
tPHL Propagation Delay Time,
HIGH-to-LOW Level Output
310ns
tPZH Output Enable Time to HIGH
Level Output
1G Y321ns
tPZL Output Enable Time to HIGH
Level Output
321ns
tPHZ Output Disable Time to HIGH
Level Output
1G Y210ns
tPLZ Output Disable Time to LOW
Level Output
315ns
tPZH Output Enable Time to HIGH
Level Output
2G Y 7 21 ns
tPZL Output Enable Time to LOW
Level Output
721ns
tPHZ Output Disable Time from
HIGH Level Output
2G Y 2 10 ns
tPLZ Output Disable Time from
LOW Level Output
315ns
DM74ALS240A, DM74ALS241A Octal 3-STATE Bus Driver
©1986 Fairchild Semiconductor Corporation www.fairchildsemi.com
DM74ALS240A, DM74ALS241A Rev. 1.3 6
Physical Dimensions
Dimensions are in millimeters unless otherwise noted.
Figure 1. 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300" Wide
Package Number M20B
DM74ALS240A, DM74ALS241A Octal 3-STATE Bus Driver
©1986 Fairchild Semiconductor Corporation www.fairchildsemi.com
DM74ALS240A, DM74ALS241A Rev. 1.3 7
Physical Dimensions (Continued)
Dimensions are in millimeters unless otherwise noted.
Figure 2. 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
Package Number M20D
DM74ALS240A, DM74ALS241A Octal 3-STATE Bus Driver
©1986 Fairchild Semiconductor Corporation www.fairchildsemi.com
DM74ALS240A, DM74ALS241A Rev. 1.3 8
Physical Dimensions (Continued)
Dimensions are in inches (millimeters) unless otherwise noted.
Figure 3. 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide
Package Number N20A
DM74ALS240A, DM74ALS241A Octal 3-STATE Bus Driver
©1986 Fairchild Semiconductor Corporation www.fairchildsemi.com
DM74ALS240A, DM74ALS241A Rev. 1.3 9
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WORLDWIDE TERMS AND CONDITIONS, SPECIFICALLY THE WARRANTY THEREIN, WHICH COVERS THESE PRODUCTS.
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FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR
SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL 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 reasonably expected to
result in a significant injury of the user.
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.
PRODUCT STATUS DEFINITIONS
Definition of Terms
Datasheet Identification Product Status Definition
Advance Information Formative or In Design This datasheet contains the design specifications for product
development. Specifications may change in any manner without notice.
Preliminary First Production This datasheet contains preliminary data; supplementary data will be
published at a later date. Fairchild Semiconductor reserves the right to
make changes at any time without notice to improve design.
No Identification Needed Full Production This datasheet contains final specifications. Fairchild Semiconductor
reserves the right to make changes at any time without notice to improve
design.
Obsolete Not In Production This datasheet contains specifications on a product that has been
discontinued by Fairchild Semiconductor. The datasheet is printed for
reference information only.
Rev. I31
