TECHNICAL DATA
301
Octal 3-State Noninverting
Bus Transceiver
High-Performance Silicon-Gate CMOS
The IN74HC245A is identical in pinout to the LS/ALS245. The
device inputs are compatible with standard CMOS outputs; with pullup
resistors, they are compatible with LS/ALSTTL outputs.
The IN74HC245A 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
High Noise Immunity Characteristic of CMOS Devices
IN74HC245A
ORDERING INFORMATION
IN74HC245AN Plastic
IN74HC245ADW SOIC
T
A
= -55
to 125
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
IN74HC245A
302
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)
-1.5 to V
CC
+1.5
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 Current, per Pin
35
mA
I
CC
DC Supply Current, V
CC
and GND Pins
75
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
A
Operating Temperature, All Package Types
-55
+125
C
t
r
, t
f
Input Rise and Fall Time (Figure 1)
V
CC
=2.0 V
V
CC
=4.5 V
V
CC
=6.0 V
0
0
0
1000
500
400
ns
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.
IN74HC245A
303
DC ELECTRICAL CHARACTERISTICS
(Voltages Referenced to GND)
V
CC
Guaranteed Limit
Symbol
Parameter
Test Conditions
V
25
C
to
-55
C
85
C
125
C
Unit
V
IH
Minimum High-Level
Input Voltage
V
OUT
=0.1 V or V
CC
-0.1 V
I
OUT
20
A
2.0
4.5
6.0
1.5
3.15
4.2
1.5
3.15
4.2
1.5
3.15
4.2
V
V
IL
Maximum Low -
Level Input Voltage
V
OUT
=0.1 V or V
CC
-0.1 V
I
OUT
20
A
2.0
4.5
6.0
0.5
1.35
1.8
0.5
1.35
1.8
0.5
1.35
1.8
V
V
OH
Minimum High-Level
Output Voltage
V
IN
=V
IH
or V
IL
I
OUT
20
A
2.0
4.5
6.0
1.9
4.4
5.9
1.9
4.4
5.9
1.9
4.4
5.9
V
V
IN
=V
IH
or V
IL
I
OUT
6.0 mA
I
OUT
7.8 mA
4.5
6.0
3.98
5.48
3.84
5.34
3.7
5.2
V
OL
Maximum Low-Level
Output Voltage
V
IN
= V
IL
or V
IH
I
OUT
20
A
2.0
4.5
6.0
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
V
V
IN
= V
IL
or V
IH
I
OUT
6.0 mA
I
OUT
7.8 mA
4.5
6.0
0.26
0.26
0.33
0.33
0.4
0.4
I
IN
Maximum Input
Leakage Current
V
IN
=V
CC
or GND, Pin 1 or
19
6.0
0.1
1.0
1.0
A
I
OZ
Maximum Three-
State Leakage
Current
Output in High-Impedance
State
V
IN
= V
IL
or V
IH
V
OUT
=V
CC
or GND, I/O Pins
6.0
0.5
5.0
10
A
I
CC
Maximum Quiescent
Supply Current
(per Package)
V
IN
=V
CC
or GND
I
OUT
=0
A
6.0
4.0
40
160
A
IN74HC245A
304
AC ELECTRICAL CHARACTERISTICS
(C
L
=50pF,Input t
r
=t
f
=6.0 ns)
V
CC
Guaranteed Limit
Symbol
Parameter
V
25
C
to
-55
C
85
C
125
C
Unit
t
PLH
, t
PHL
Maximum Propagation Delay, A to B or B
to A (Figures 1 and 3)
2.0
4.5
6.0
75
15
13
95
19
16
110
22
19
ns
t
PLZ
, t
PHZ
Maximum Propagation Delay , Direction or
Output Enable to A or B (Figures 2 and 4)
2.0
4.5
6.0
110
22
19
140
28
24
165
33
28
ns
t
PZL
, t
PZH
Maximum Propagation Delay , Direction or
Output Enable to A or B (Figures 2 and 4)
2.0
4.5
6.0
110
22
19
140
28
24
165
33
28
ns
t
TLH
, t
THL
Maximum Output Transition Time, Any Output
(Figures 1 and 3)
2.0
4.5
6.0
60
12
10
75
15
13
90
18
15
ns
C
IN
Maximum Input Capacitance (Pin 1 or Pin 19)
-
10
10
10
pF
C
OUT
Maximum Three-State I/O Capacitance
(I/O in High-Impedance State)
-
15
15
15
pF
Power Dissipation Capacitance (Per Transceiver
Channel)
Typical @25
C,V
CC
=5.0 V
C
PD
Used to determine the no-load dynamic power
consumption:
P
D
=C
PD
V
CC
2
f+I
CC
V
CC
40
pF
Figure 1. Switching Waveforms
Figure 2. Switching Waveforms
IN74HC245A
305
Figure 3. Test Circuit
Figure 4. Test Circuit
EXPANDED LOGIC DIAGRAM
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