TECHNICAL DATA
326
Octal 3-State Noninverting
Bus Transceiver
High-Speed Silicon-Gate CMOS
The IN74AC245 is identical in pinout to the LS/ALS245,
HC/HCT245. The device inputs are compatible with standard CMOS
outputs; with pullup resistors, they are compatible with LS/ALS
outputs.
The IN74AC245 is a 3-state noninverting transceiver that is used
for 2-way asynchronous communication between data buses. The
device has an active-low Output Enable pin, which is used to place the
I/O ports into high-impedance states. The Direction control determines
whether data flows from A to B or from B to A.
Outputs Directly Interface to CMOS, NMOS, and TTL
Operating Voltage Range: 2.0 to 6.0 V
Low Input Current: 1.0
A; 0.1
A @ 25
C
High Noise Immunity Characteristic of CMOS Devices
Outputs Source/Sink 24 mA
IN74AC245
ORDERING INFORMATION
IN74AC245N Plastic
IN74AC245DW SOIC
T
A
= -40
to 85
C for all
packages
PIN ASSIGNMENT
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
LOGIC DIAGRAM
PIN 20=V
CC
PIN 10 = GND
IN74AC245
327
MAXIMUM RATINGS
*
Symbol
Parameter
Value
Unit
V
CC
DC Supply Voltage (Referenced to GND)
-0.5 to +7.0
V
V
IN
DC Input Voltage (Referenced to GND)
-0.5 to V
CC
+0.5
V
V
OUT
DC Output Voltage (Referenced to GND)
-0.5 to V
CC
+0.5
V
I
IN
DC Input Current, per Pin
20
mA
I
OUT
DC Output Sink/Source Current, per Pin
50
mA
I
CC
DC Supply Current, V
CC
and GND Pins
50
mA
P
D
Power Dissipation in Still Air, Plastic DIP+
SOIC Package+
750
500
mW
Tstg
Storage Temperature
-65 to +150
C
T
L
Lead Temperature, 1 mm from Case for 10 Seconds
(Plastic DIP or SOIC Package)
260
C
*
Maximum Ratings are those values beyond which damage to the device may occur.
Functional operation should be restricted to the Recommended Operating Conditions.
+Derating - Plastic DIP: - 10 mW/
C from 65
to 125
C
SOIC Package: : - 7 mW/
C from 65
to 125
C
RECOMMENDED OPERATING CONDITIONS
Symbol
Parameter
Min
Max
Unit
V
CC
DC Supply Voltage (Referenced to GND)
2.0
6.0
V
V
IN
, V
OUT
DC Input Voltage, Output Voltage (Referenced to GND)
0
V
CC
V
T
J
Junction Temperature (PDIP)
140
C
T
A
Operating Temperature, All Package Types
-40
+85
C
I
OH
Output Current - High
-24
mA
I
OL
Output Current - Low
24
mA
t
r
, t
f
Input Rise and Fall Time
*
(except Schmitt Inputs)
V
CC
=3.0 V
V
CC
=4.5 V
V
CC
=5.5 V
0
0
0
150
40
25
ns/V
*
V
IN
from 30% to 70% V
CC
This device contains protection circuitry to guard against damage due to high static voltages or electric
fields. However, precautions must be taken to avoid applications of any voltage higher than maximum rated
voltages to this high-impedance circuit. For proper operation, V
IN
and V
OUT
should be constrained to the range
GND
(V
IN
or V
OUT
)
V
CC
.
Unused inputs must always be tied to an appropriate logic voltage level (e.g., either GND or V
CC
).
Unused outputs must be left open.
IN74AC245
328
DC ELECTRICAL CHARACTERISTICS
(Voltages Referenced to GND)
V
CC
Guaranteed Limits
Symbol
Parameter
Test Conditions
V
25
C
-40
C to
85
C
Unit
V
IH
Minimum High-Level
Input Voltage
V
OUT
=0.1 V or V
CC
-0.1 V
3.0
4.5
5.5
2.1
3.15
3.85
2.1
3.15
3.85
V
V
IL
Maximum Low -
Level Input Voltage
V
OUT
=0.1 V or V
CC
-0.1 V
3.0
4.5
5.5
0.9
1.35
1.65
0.9
1.35
1.65
V
V
OH
Minimum High-Level
Output Voltage
I
OUT
-50
A
3.0
4.5
5.5
2.9
4.4
5.4
2.9
4.4
5.4
V
*
V
IN
=V
IH
or V
IL
I
OH
=-12 mA
I
OH
=-24 mA
I
OH
=-24 mA
3.0
4.5
5.5
2.56
3.86
4.86
2.46
3.76
4.76
V
OL
Maximum Low-Level
Output Voltage
I
OUT
50
A
3.0
4.5
5.5
0.1
0.1
0.1
0.1
0.1
0.1
V
*
V
IN
= V
IH
or V
IL
I
OL
=12 mA
I
OL
=24 mA
I
OL
=24 mA
3.0
4.5
5.5
0.36
0.36
0.36
0.44
0.44
0.44
I
IN
Maximum Input
Leakage Current
V
IN
=V
CC
or GND
5.5
0.1
1.0
A
I
OZ
Maximum Three-
State Leakage
Current
V
IN
(OE)= V
IH
or V
IL
V
IN
=V
CC
or GND
V
OUT
=V
CC
or GND
5.5
0.6
6.0
A
I
OLD
+Minimum Dynamic
Output Current
V
OLD
=1.65 V Max
5.5
75
mA
I
OHD
+Minimum Dynamic
Output Current
V
OHD
=3.85 V Min
5.5
-75
mA
I
CC
Maximum Quiescent
Supply Current
(per Package)
V
IN
=V
CC
or GND
5.5
8.0
80
A
*
All outputs loaded; thresholds on input associated with output under test.
+Maximum test duration 2.0 ms, one output loaded at a time.
Note: I
IN
and I
CC
@ 3.0 V are guaranteed to be less than or equal to the respective limit @ 5.5 V V
CC
IN74AC245
329
AC ELECTRICAL CHARACTERISTICS
(C
L
=50pF, Input t
r
=t
f
=3.0 ns)
V
CC
*
Guaranteed Limits
Symbol
Parameter
V
25
C
-40
C to
85
C
Unit
Min
Max
Min
Max
t
PLH
Propagation Delay, A to B, B to A
(Figure 1)
3.3
5.0
1.5
1.5
8.5
6.5
1.0
1.0
9.0
7.0
ns
t
PHL
Propagation Delay, A to B, B to A
(Figure 1)
3.3
5.0
1.5
1.5
8.5
6.0
1.0
1.0
9.0
7.0
ns
t
PZH
Propagation Delay, Direction or Output
Enable to A or B (Figure 2)
3.3
5.0
1.5
1.5
11.5
8.5
2.0
1.0
12.5
9.0
ns
t
PZL
Propagation Delay, Direction or Output
Enable to A or B (Figure 2)
3.3
5.0
2.5
1.5
12.0
9.0
2.0
1.0
13.5
9.5
ns
t
PHZ
Propagation Delay, Direction or Output
Enable to A or B (Figure 2)
3.3
5.0
2.0
1.5
12.0
9.0
1.0
1.0
12.5
10.0
ns
t
PLZ
Propagation Delay, Direction or Output
Enable to A or B (Figure 2)
3.3
5.0
2.0
1.5
11.5
9.0
1.5
1.0
13.0
10.0
ns
C
IN
Maximum Input Capacitance
5.0
4.5
4.5
pF
C
OUT
Maximum Three-State I/O Capacitance
(I/O in High-Impedance State)
5.0
15
15
pF
Typical @25
C,V
CC
=5.0 V
C
PD
Power Dissipation Capacitance
45
pF
*
Voltage Range 3.3 V is 3.3 V
0.3 V
Voltage Range 5.0 V is 5.0 V
0.5 V
Figure 1. Switching Waveforms
Figure 2. Switching Waveforms
IN74AC245
330
EXPANDED LOGIC DIAGRAM
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