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Электронный компонент: IN74LS245

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TECHNICAL DATA
IN74LS245
Octal 3-State Noninverting
Bus Transceiver
ORDERING INFORMATION
IN74LS245N Plastic
IN74LS245DW SOIC
T
A
= 0
to 70 C for all packages
These octal bus transceiver are designed for asynchronous two-way
communication between data buses. The control function implementation
minimized external timing requirements.
The device allows data transmission from the A bus to the B bus or
from the B bus to the A bus depending upon the logic level at the
directional control (DIR) input. The enable input(E) can be used to
disable the device so that the buses are effectively isolated.
Bidirectional Bus Transceiver in a High-Density 20-Pin Package
3-state Outputs Dirve Bus Lines Directly
P-N-P Inputs D-C Loading on Bus Lines
Hysteresis at Bus Inputs Improve Noise Margins
Typical Propagation Delay Times; Port to Port ... 8 ns
PIN ASSIGNMENT
LOGIC DIAGRAM
PIN 20=V
CC
PIN 10 = GND
FUNCTION TABLE
Control Inputs
Output
Enable
Direction Operation
L L
Data
Transmitted
from Bus B to
Bus A
L H
Data
Transmitted
from Bus A to
Bus B
H X
Buses
Isolated
(High Impedance
State)
X = don't care
1
IN74LS245
MAXIMUM RATINGS
*
Symbol Parameter
Value
Unit
V
CC
Supply Voltage
7.0
V
V
IN
Input Voltage
7.0
V
V
OUT
Output Voltage
5.5
V
Tstg
Storage Temperature Range
-65 to +150
C
*
Maximum Ratings are those values beyond which damage to the device may occur.
Functional operation should be restricted to the Recommended Operating Conditions.
RECOMMENDED OPERATING CONDITIONS
Symbol Parameter
Min
Max
Unit
V
CC
Supply Voltage
4.75
5.25
V
V
IH
High Level Input Voltage
2.0
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
Ambient Temperature Range
0
+70
C
DC ELECTRICAL CHARACTERISTICS over full operating conditions
Guaranteed
Limit
Symbol Parameter
Test
Conditions
Min
Max
Unit
V
IK
Input Clamp Voltage
V
CC
= min, I
IN
= -18 mA
-1.5
V
V
OH
High Level Output Voltage
V
CC
= min, I
OH
= -1.0 mA
2.7
V
V
CC
= min, I
OH
= -3.0 mA
2.4
V
CC
= min, I
OH
= -15 mA
2.0
V
OL
Low Level Output Voltage
V
CC
= min, I
OL
= 12 mA
0.4
V
V
CC
= min, I
OL
= 24 mA
0.5
V
T+
- V
T-
Hysteresis V
CC
= min
0.2
V
I
OZH
Output Off Current HIGH
V
CC
= max, V
OUT
= 2.7 V
20
A
I
OZL
Output Off Current LOW
V
CC
= max, V
OUT
= 0.4 V
-0.2
mA
I
IH
High Level Input Current
V
CC
= max, V
IN
= 2.7 V
20
A
V
CC
= max, V
IN
= 5.5 V
(A or B)
0.1
mA
V
CC
= max, V
IN
= 7.0 V
for Pin1, Pin 19
0.1
I
IL
Low Level Input Current
V
CC
= max, V
IN
= 0.4 V
-0.2
mA
I
O
Output Short Circuit Current
V
CC
= max, V
O
=0 V
(Note 1)
-40 -225
mA
I
CC
Supply Outputs
High
V
CC
= max
70
mA
Current
Outputs Low
Outputs open
90
All outputs disable
95
Note 1: Not more thanone output should be shorted at a time, and duration of the short-circuit should not exceed one
second.
2
IN74LS245
AC ELECTRICAL CHARACTERISTICS
(T
A
= 25
C, V
CC
= 5.0 V, t
r
= 15 ns,,
t
f
= 6.0 ns)
Symbol Parameter Test
Condition
Min
Max
Unit
t
PLH
Propagation Delay Time, Low-to-High
Level Output (from A or B to Output)
12
ns
t
PHL
Propagation Delay Time, High-to-Low
Level Output (from A or B to Output)
C
L
= 45 pF,
R
L
= 667
12
ns
t
PZH
Output Enable Time to High Level (from
OE to Output)
40
ns
t
PZL
Output Enable Time to Low Level (from OE
to Output)
40
ns
t
PHZ
Output Disable Time from High Level
(from OE to Output)

C
L
= 5 pF
25
ns
t
PLZ
Output Disable Time from Low Level
(from OE to Output)
R
L
= 667
25
ns
t
PZL
- S1 closed, S2 opened
t
PZH
- S1 opened, S2 closed
t
PLZ
, t
PHZ
- S1 and S2 closed
Figure 1. Switching Waveforms
(See Figure 3)

Figure 2. Switching Waveforms
(See Figure 4)
NOTES A. C
L
includes probe and jig capacitance.
B. All diodes are 1N916 or 1N3064.
NOTES A. C
L
includes probe and jig capacitance.
B. All diodes are 1N916 or 1N3064.
Figure 3. Test Circuit
Figure 4. Test Circuit
3
IN74LS245
EXPANDED LOGIC DIAGRAM



















4
IN74LS245
N SUFFIX PLASTIC DIP
(MS - 001AD)
Symbol
MIN
MAX
A
24.89
26.92
B
6.1
7.11
C
5.33
D
0.36
0.56
F
1.14
1.78
G
H
J
0
10
K
2.92
3.81
NOTES:
L
7.62
8.26
1.
Dimensions "A", "B" do not include mold flash or protrusions.
M
0.2
0.36
Maximum mold flash or protrusions 0.25 mm (0.010) per side.
N
0.38
D SUFFIX SOIC
(MS - 013AC)
Symbol
MIN
MAX
A
12.6
13
B
7.4
7.6
C
2.35
2.65
D
0.33
0.51
F
0.4
1.27
G
H
NOTES:
J
0
8
1.
Dimensions A and B do not include mold flash or protrusion.
K
0.1
0.3
2.
Maximum mold flash or protrusion 0.15 mm (0.006) per side
M
0.23
0.32
for A; for B 0.25 mm (0.010) per side.
P
10
10.65
R
0.25
0.75
Dimension, mm
1.27
9.53
Dimension, mm
2.54
7.62
A
B
H
C
K
C M
J
F
M
P
G
D
R x 45
SEATING
PLANE
0.25 (0.010) M T
-T-
1
20
10
11
L
H
M
J
A
B
F
G
D
SEATING
PLANE
N
K
0.25 (0.010) M T
-T-
C
1
20
10
11
5