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Fairchild Semiconductor |
August 1986
Revised March 2000
DM74LS244
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 IOL (sink current)
24 mA
s Typical IOH (source current) −15 mA
s Typical propagation delay times
Inverting
10.5 ns
Noninverting 12 ns
s Typical enable/disable time 18 ns
s Typical power dissipation (enabled)
Inverting
130 mW
Noninverting 135 mW
Ordering Code:
Order Number Package Number
Package Description
DM74LS244WM
M20B
20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
DM74LS244SJ
M20D
20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
DM74LS244N
N20A
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Connection Diagram
Function Table
Inputs
GA
LL
LH
HX
L = LOW Logic Level
H = HIGH Logic Level
X = Either LOW or HIGH Logic Level
Z = High Impedance
Output
Y
L
H
Z
© 2000 Fairchild Semiconductor Corporation DS008442
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Absolute Maximum Ratings(Note 1)
Supply Voltage
7V
Input Voltage
7V
Operating Free Air Temperature Range 0°C to +70°C
Storage Temperature Range
−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
VCC
VIH
VIL
IOH
IOL
TA
Parameter
Supply Voltage
HIGH Level Input Voltage
LOW Level Input Voltage
HIGH Level Output Current
LOW Level Output Current
Free Air Operating Temperature
Min
4.75
2
Nom
5
0
Electrical Characteristics
over recommended operating free air temperature range (unless otherwise noted)
Symbol
Parameter
Conditions
Min
VI
HYS
Input Clamp Voltage
Hysteresis (VT+ − VT−)
Data Inputs Only
VCC = Min, II = −18 mA
VCC = Min
0.2
VOH HIGH Level Output Voltage
VOL LOW Level Output Voltage
IOZH
IOZL
Off-State Output Current,
HIGH Level Voltage Applied
Off-State Output Current,
LOW Level Voltage Applied
VCC = Min, VIH = Min
VIL = Max, IOH = −1 mA
VCC = Min, VIH = Min
VIL = Max, IOH = −3 mA
VCC = Min, VIH = Min
VIL = 0.5V, IOH = Max
VCC = Min
VIL = Max
VIH = Min
VCC = Max
VIL = Max
VIH = Min
IOL = 12 mA
IOL = Max
VO = 2.7V
VO = 0.4V
2.7
2.4
2
II Input Current at Maximum
Input Voltage
VCC = Max
VI = 7V
IIH HIGH Level Input Current
IIL LOW Level Input Current
IOS Short Circuit Output Current
ICC Supply Current
VCC = Max
VCC = Max
VCC = Max (Note 3)
VCC = Max,
Outputs Open
VI = 2.7V
VI = 0.4V
Outputs HIGH
Outputs LOW
−0.5
−40
Outputs Disabled
Note 2: All typicals are at VCC = 5V, TA = 25°C.
Note 3: Not more than one output should be shorted at a time, and the duration should not exceed one second.
Max
5.25
0.8
−15
24
70
Typ
(Note 2)
0.4
3.4
13
27
32
Units
V
V
V
mA
mA
°C
Max
−1.5
Units
V
V
V
0.4
0.5
20
−20
0.1
20
−200
−225
23
46
54
V
µA
µA
mA
µA
µA
mA
mA
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