TECHNICAL DATA
IN74LS245
Octal 3-State Noninverting
Bus Transceiver
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
ORDERING INFORMATION
IN74LS245N Plastic
IN74LS245DW SOIC
T
A
= 0° to 70° C for all packages
PIN ASSIGNMENT
LOGIC DIAGRAM
FUNCTION TABLE
Control Inputs
Output
Enable
L
Direction
L
Operation
Data Transmitted
from Bus B to
Bus A
Data Transmitted
from Bus A to
Bus B
Buses Isolated
(High Impedance
State)
PIN 20=V
CC
PIN 10 = GND
L
H
H
X
X = don’t care
Rev. 00
IN74LS245
MAXIMUM RATINGS
*
Symbol
V
CC
V
IN
V
OUT
Tstg
*
Parameter
Supply Voltage
Input Voltage
Output Voltage
Storage Temperature Range
Value
7.0
7.0
5.5
-65 to +150
Unit
V
V
V
°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
V
CC
V
IH
V
IL
I
OH
I
OL
T
A
Supply Voltage
High Level Input Voltage
Low Level Input Voltage
High Level Output Current
Low Level Output Current
Ambient Temperature Range
0
Parameter
Min
4.75
2.0
0.8
-15
24
+70
Max
5.25
Unit
V
V
V
mA
mA
°C
DC ELECTRICAL CHARACTERISTICS
over full operating conditions
Guaranteed Limit
Symbol
V
IK
V
OH
Parameter
Input Clamp Voltage
High Level Output Voltage
Test Conditions
V
CC
= min, I
IN
= -18 mA
V
CC
= min, I
OH
= -1.0 mA
V
CC
= min, I
OH
= -3.0 mA
V
CC
= min, I
OH
= -15 mA
V
OL
V
T+
- V
T-
I
OZH
I
OZL
I
IH
Low Level Output Voltage
Hysteresis
Output Off Current HIGH
Output Off Current LOW
High Level Input Current
V
CC
= min, I
OL
= 12 mA
V
CC
= min, I
OL
= 24 mA
V
CC
= min
V
CC
= max, V
OUT
= 2.7 V
V
CC
= max, V
OUT
= 0.4 V
V
CC
= max, V
IN
= 2.7 V
V
CC
= max, V
IN
= 5.5 V
(A or B)
V
CC
= max, V
IN
= 7.0 V
for Pin1, Pin 19
I
IL
I
O
I
CC
Low Level Input Current
Output Short Circuit Current
Supply
Current
Outputs High
Outputs Low
V
CC
= max, V
IN
= 0.4 V
V
CC
= max, V
O
=0 V
(Note 1)
V
CC
= max
Outputs open
-40
0.2
20
-0.2
20
0.1
0.1
-0.2
-225
70
90
mA
mA
mA
2.7
2.4
2.0
0.4
0.5
V
μA
mA
μA
mA
V
Min
Max
-1.5
Unit
V
V
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.
Rev. 00
IN74LS245
AC ELECTRICAL CHARACTERISTICS
(T
A
= 25°C, V
CC
= 5.0 V, t
r
= 15 ns,,
t
f
= 6.0 ns)
Symbol
t
PLH
t
PHL
t
PZH
t
PZL
t
PHZ
t
PLZ
Parameter
Propagation Delay Time, Low-to-High
Level Output (from A or B to Output)
Propagation Delay Time, High-to-Low
Level Output (from A or B to Output)
Output Enable Time to High Level (from
OE to Output)
Output Enable Time to Low Level (from OE
to Output)
Output Disable Time from High Level
(from OE to Output)
Output Disable Time from Low Level
(from OE to Output)
C
L
= 5 pF
R
L
= 667
Ω
25
ns
C
L
= 45 pF,
R
L
= 667
Ω
Test Condition
Min
Max
12
12
40
40
25
Unit
ns
ns
ns
ns
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.
Figure 3. Test Circuit
NOTES A. C
L
includes probe and jig capacitance.
B. All diodes are 1N916 or 1N3064.
Figure 4. Test Circuit
Rev. 00
IN74LS245
EXPANDED LOGIC DIAGRAM
Rev. 00
IN74LS245
N SUFFIX PLASTIC DIP
(MS - 001AD)
A
Dimension, mm
20
11
B
1
10
Symbol
A
B
C
MIN
24.89
6.1
MAX
26.92
7.11
5.33
F
L
D
F
0.36
1.14
2.54
7.62
0°
2.92
7.62
0.2
0.38
0.56
1.78
C
-T-
SEATING
PLANE
G
H
H
J
N
G
D
0.25 (0.010) M T
K
M
J
K
L
M
N
10°
3.81
8.26
0.36
NOTES:
1. Dimensions “A”, “B” do not include mold flash or protrusions.
Maximum mold flash or protrusions 0.25 mm (0.010) per side.
D SUFFIX SOIC
(MS - 013AC)
A
20
11
Dimension, mm
Symbol
MIN
12.6
7.4
2.35
0.33
0.4
1.27
9.53
0
°
0.1
0.23
10
0.25
8
°
0.3
0.32
10.65
0.75
MAX
13
7.6
2.65
0.51
1.27
H
B
P
A
B
1
G
10
C
R x 45
C
D
F
-T-
D
0.25 (0.010) M T C M
K
SEATING
PLANE
J
F
M
G
H
J
K
M
P
R
NOTES:
1. Dimensions A and B do not include mold flash or protrusion.
2. Maximum mold flash or protrusion 0.15 mm (0.006) per side
for A; for B
‑
0.25 mm (0.010) per side.
Rev. 00
单片机
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