TECHNICAL DATA
1
Octal 3-State Noninverting
Bus Transceiver
This device contains eight pairs of 3-state logic elements designed
for asynchronous two-way communication between data buses.
These circuits are suited for use in memory, microprocessor
systems and asynchronous bi-directional data buses. The Enable input
(E) can be used to isolate the buses.
Non-inverting logic output
Switching response specified into 500
/50 pF
Switching specifications guaranteed over full temperature and V
CC
range
Low level drive current:
54ALS = 12 mA, 74ALS = 24 mA
IN74ALS245
ORDERING INFORMATION
IN74ALS245N Plastic
IN74ALS245DW SOIC
T
A
= -10
to 70
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
IN74ALS245
2
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
4.5
5.5
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
-10
+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
= -0.4 mA
2.5
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
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
-20
A
I
IH
High Level Input Current
V
CC
= max, V
IN
= 2.7 V
20
A
V
CC
= max, V
IN
= 5.5 V
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
-0.1
mA
I
O
Output Short Circuit Current
V
CC
= max, V
O
= 2.25 V
-30
-112
mA
I
CC
Supply Current
V
CC
= max
Outputs High
45
mA
Outputs Low
55
3-State
(High Z)
58
IN74ALS245
3
AC ELECTRICAL CHARACTERISTICS over full operating conditions
(V
CC
= 5.0 V
10%,
C
L
= 50 pF, R
L1:
= R
L2
= 500
, Input t
r
= t
f
= 2.0 ns)
Symbol
Parameter
Min
Max
Unit
t
PLH
Propagation Delay Time, Low-to-High Level Output (from
A or B to Output)
10
ns
t
PHL
Propagation Delay Time, High-to-Low Level Output (from
A or B to Output)
10
ns
t
PZH
Output Enable Time to High Level (from OE to Output)
20
ns
t
PZL
Output Enable Time to Low Level (from OE to Output)
20
ns
t
PHZ
Output Disable Time from High Level
(from OE to Output)
40
ns
t
PLZ
Output Disable Time from Low Level
(from OE to Output)
35
ns
t
PZL
, t
PLZ
- S1 closed
t
PZH
, t
PHZ
- S1 opened
Figure 1. Switching Waveforms
Figure 2. Switching Waveforms
* Includes all probe and jig capacitance.
* Includes all probe and jig capacitance.
Figure 3. Test Circuit
Figure 4. Test Circuit
IN74ALS245
4
EXPANDED LOGIC DIAGRAM
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