2000 Fairchild Semiconductor Corporation
DS006210
www.fairchildsemi.com
September 1986
Revised February 2000
DM74ALS240A
DM74ALS241A Octal
3-
ST
A
T
E Bus D
r
ive
r
DM74ALS240A DM74ALS241A
Octal 3-STATE Bus Driver
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 communication systems.
The output 3-STATE gating control is organized into two
separate groups of four buffers. The DM74ALS240A con-
trol inputs symmetrically enable the respective outputs
when set logic LOW, while the DM74ALS241A has comple-
mentary 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 eliminates bus glitching problems that arise
during power-up and power-down.
Features
s
Advanced low power oxide-isolated ion-implanted
Schottky TTL process
s
Functional and pin compatible with the DM74LS coun-
terpart
s
Improved switching performance with less power dissi-
pation compared with the DM74LS counterpart
s
Switching response specified into 500
and 50 pF load
s
Switching response specifications guaranteed over full
temperature and V
CC
supply range
s
PNP input design reduces input loading
s
Low level drive current: 74ALS
=
24 mA
Ordering Code:
Devices also available in Tape and Reel. Specify by appending the suffix letter "X" to the ordering code.
Connection Diagrams
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
DM74ALS241AN
N20A
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
3
www.fairchildsemi.com
DM74ALS240A
DM74ALS241A
Absolute Maximum Ratings
(Note 1)
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
Electrical Characteristics
over recommended operating free-air temperature range (unless otherwise specified)
Supply Voltage, V
CC
7V
Input Voltage
7V
Voltage Applied to Disabled Output
5.5V
Operating Free Air Temperature Range
0
C to
+
70
C
Storage Temperature Range
-
65
C to
+
150
C
Typical
JA
N Package
60.5
C/W
M Package
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
Symbol
Parameter
Conditions
Min
Typ
Max
Units
V
IK
Input Clamp Voltage
V
CC
=
4.5V, I
I
=
-
18 mA
-
1.5
V
V
OH
HIGH Level
V
CC
=
4.5V to 5.5V
I
OH
=
-
0.4 mA
V
CC
-
2
V
Output Voltage
V
CC
=
4.5V
I
OH
=
-
3 mA
2.4
V
I
OH
=
Max
2
V
V
OL
LOW
Level V
CC
=
4.5V
0.35
0.5
V
Output Voltage
I
OL
=
Max
I
I
Input Current at Max
V
CC
=
5.5V, V
I
=
7V
0.1
mA
Input Voltage
I
IH
HIGH Level Input Current
V
CC
=
5.5V, V
I
=
2.7V
20
A
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
V
CC
=
5.5V, V
O
=
2.7V
20
A
Output Current
I
OZL
LOW Level 3-STATE
V
CC
=
5.5V, V
O
=
0.4V
-
20
A
Output Current
I
CC
Supply Current
V
CC
=
5.5V, ALS240A
4
10
mA
Outputs HIGH
Outputs LOW
13
23
mA
Outputs 3-STATE
14
25
mA
V
CC
=
5.5V, ALS241A
9
15
mA
Outputs HIGH
Outputs LOW
15
26
mA
Outputs 3-STATE
17
30
mA
www.fairchildsemi.com
4
DM
74
A
L
S
2
40A
DM
74ALS24
1A
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
V
CC
=
4.5V to 5.5V,
2
9
ns
LOW-to-HIGH Level Output
C
L
=
50 pF,
A
Y
t
PHL
Propagation Delay Time
R1
=
500
,
2
9
ns
HIGH-to-LOW Level Output
R2
=
500
,
t
PZH
Output Enable Time
T
A
=
Min to Max
3
13
ns
to HIGH Level Output
G
Y
t
PZL
Output Enable Time
3
18
ns
to LOW Level Output
t
PHZ
Output Disable Time
2
10
ns
from HIGH Level Output
G
Y
t
PLZ
Output Disable Time
3
12
ns
from LOW Level Output
Symbol
Parameter
Conditions
From
(Input)
To
(Output)
Min
Max
Units
t
PLH
Propagation Delay Time
V
CC
=
4.5V to 5.5V,
3
11
ns
LOW-to-HIGH Level Output
C
L
=
50 pF,
A
Y
t
PHL
Propagation Delay Time
R1
=
500
,
3
10
ns
HIGH-to-LOW Level Output
R2
=
500
,
t
PZH
Output Enable Time
T
A
=
Min to Max
3
21
ns
to HIGH Level Output
1G
Y
t
PZL
Output Enable Time
3
21
ns
to HIGH Level Output
t
PHZ
Output Disable Time
2
10
ns
to HIGH Level Output
1G
Y
t
PLZ
Output Disable Time
3
15
ns
to LOW Level Output
t
PZH
Output Enable Time
7
21
ns
to HIGH Level Output
2G
Y
t
PZL
Output Enable Time
7
21
ns
to LOW Level Output
t
PHZ
Output Disable Time
2
10
ns
from HIGH Level Output
2G
Y
t
PLZ
Output Disable Time
3
15
ns
from LOW Level Output
PDF 
ZIP
