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DM74AS240N

P1-P3P4-P5
© 2000 Fairchild Semiconductor Corporation DS006298 www.fairchildsemi.com
October 1986
Revised March 2000
DM74AS240 • DM74AS244 3-STATE Bus Driver/Receiver
DM74AS240 • DM74AS244
3-STATE Bus Driver/Receiver
General Description
This family of Advance Schottky 3-STATE Bus circuits are
designed to provide either bidirectional or unidirectional
buffer interface in Memory, Microprocessor, and Communi-
cation Systems. The output characteristics of the circuits
have low impedance sufficient to drive terminated trans-
mission lines down to 133Ω. The input characteristics of
the circuits likewise have a high impedance so it will not
significantly load the transmission line. The package con-
tains eight 3-STATE buffers organized with four buffers
having a common 3-STATE enable gate. The DM74AS240
and DM74AS244 are eight wide in a 20 pin package, and
may be used as a 4 wide bidirectional or eight wide unidi-
rectional. The buffer selection includes inverting and non-
inverting, with enable or disable 3-STATE control.
Features
■ Advanced oxide-isolated, ion-implanted Schottky TTL
process
■ Improved switching performance with less power dissi-
pation compared with Schottky counterpart
■ Functional and pin compatible with 74LS and Schottky
counterpart
■ Switching response specified into 500Ω and 50 pF
■ Specified to interface with CMOS at V
OH
= V
CC
− 2V
Ordering Code:
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Connection Diagrams
DM74AS240 DM74AS244
Function Tables
DM74AS240 DM74AS244
L = LOW Logic Level H = HIGH Logic Level X = Either LOW or HIGH Logic Level Z = High Impedance
Order Number Package Number Package Description
DM74AS240WM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
DM74AS240N N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
DM74AS244WM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
DM74AS244N N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Inputs Output
G
AY
LL H
LH L
HX Z
Inputs Output
G
AY
LL L
LH H
HX Z
www.fairchildsemi.com 2
DM74AS240 • DM74AS244
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. All typical values are measured at V
CC
= 5V, T
A
= 25°C.
Note 2: The output conditions have been chosen to produce a current that closely approximates one half the true short-circuit output current, I
OS
.
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 θ
JA
N Package 57.0°C/W
M Package 76.0°C/W
Symbol Parameter Min Nom 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 64 mA
T
A
Free Air Operating Temperature 0 70 °C
Symbol Parameter Conditions Min Typ Max Units
V
IK
Input Clamp Voltage V
CC
= 4.5V, I
IN
= −18 mA −1.2 V
V
OH
HIGH Level V
CC
= 4.5V, I
OH
= −3 mA 2.4 3.2
VOutput Voltage V
CC
= 4.5V, I
OH
= Max 2.4
I
OH
= −2 mA, V
CC
= 4.5V to 5.5V V
CC
−2
V
OL
LOW Level Output Voltage V
CC
= 4.5V, I
OL
= Max 0.35 0.55 V
I
I
Input Current at Max Input Voltage V
CC
= 5.5V V
IN
= 7V Others 100 µA
I
IH
HIGH Level Input Current V
CC
= 5.5V, V
IN
= 2.7V Others 20 µA
I
IL
LOW Level Input Current V
CC
= 5.5V, V
IN
= 0.4V AS240, (G, G),
µA
(Control Inputs), −500
DM74AS244 (G)
DM74AS244 (A) −1000
I
OZH
HIGH Level 3-STATE Output Current V
CC
= 5.5V, V= 2.7V 50 µA
I
OZL
LOW Level 3-STATE
V
CC
= 5.5V, V = 0.4V
DM74AS240,
−50 µA
Output Current DM74AS244
I
O
(Note 2) Output Drive Current V
CC
= 5.5V, V
OUT
= 2.25V −50 −115 −150 mA
I
CC
DM74AS240 V
CC
= 5.5V Outputs HIGH 11 17
Supply Current Outputs LOW 51 75 mA
3-STATE 24 38
I
CC
DM74AS244 V
CC
= 5.5V Outputs HIGH 22 34
Supply Current Outputs LOW 60 90 mA
3-STATE 34 54
3 www.fairchildsemi.com
DM74AS240 • DM74AS244
DM74AS240 Switching Characteristics
over recommended operating free air temperature range
DM74AS244 Switching Characteristics
over recommended operating free air temperature range
Symbol Parameter Conditions
From To
Min Max Units
(Input) (Output)
t
PLH
Propagation Delay Time V
CC
= 4.5V to 5.5V
AY26.5ns
LOW-to-HIGH Level Output R
1
= R
2
= 500Ω
t
PHL
Propagation Delay Time C
L
= 50 pF
AY25.7ns
HIGH-to-LOW Level Output
t
PZL
Output Enable to LOW Level G Y29ns
t
PZH
Output Enable to HIGH Level G Y26.4ns
t
PLZ
Output Disable from LOW Level G Y29.5ns
t
PHZ
Output Disable from HIGH Level G Y25ns
Symbol Parameter Conditions
From To
Min Max Units
(Input) (Output)
t
PLH
Propagation Delay Time V
CC
= 4.5V to 5.5V
AY26.2ns
LOW-to-HIGH Level Output R
1
= R
2
= 500Ω
t
PHL
Propagation Delay Time C
L
= 50 pF
AY26.2ns
HIGH-to-LOW Level Output
t
PZL
Output Enable to LOW Level G Y27.5ns
t
PZH
Output Enable to HIGH Level G Y29ns
t
PLZ
Output Disable from LOW Level G Y29ns
t
PHZ
Output Disable from HIGH Level G Y26ns
P1-P3P4-P5

DM74AS240N

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Manufacturer:
ON Semiconductor / Fairchild
Description:
Buffers & Line Drivers Oct 3-STATE Driver
Lifecycle:
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