Philips
Semiconductors
74ALS245A/74ALS245A1
Octal transceiver (3State)
Product specification
IC05 Data Handbook
1991 Jun 03
INTEGRATED CIRCUITS
Philips Semiconductors
Product specification
74ALS245A/74ALS245A-1
Octal transceiver (3-State)
2
1991 Jun 03
8530011 02709
FEATURES
Octal bidirectional bus interface
3-State buffer outputs sink 24mA and source 15mA
Outputs are placed in high impedance state during power-off
conditions
The -1 version sinks 48mA
DESCRIPTION
The 74ALS245A is an octal transceiver featuring non-inverting
3-State bus compatible outputs in both transmit and receive
directions. The device features an output enable (OE) input for easy
cascading and transmit/receive (R/T) input for direction control.
The 74ALS245A-1 is the same as the 74ALS245A except that both
ports sink 48mA within the
5% V
CC
range.
TYPE
TYPICAL
PROPAGATION
DELAY
TYPICAL
SUPPLY CURRENT
(TOTAL)
74ALS245A
7.0ns
34mA
74ALS245A-1
7.0ns
34mA
PIN CONFIGURATION
SF00198
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
T/R
A0
A1
A2
A3
A4
A5
A6
A7
GND
V
CC
OE
B0
B1
B2
B3
B4
B6
B5
B7
ORDERING INFORMATION
ORDER CODE
DESCRIPTION
COMMERCIAL RANGE
V
CC
= 5V
10%,
T
amb
= 0
C to +70
C
DRAWING
NUMBER
20-pin plastic DIP
74ALS245AN,
74ALS245A-1N
SOT146-1
20-pin plastic SOL
74ALS245AD,
744ALS245A-1D
SOT163-1
20-pin plastic SSOP
Type II
74ALS245ADB,
74ALS245A-1DB
SOT339-1
INPUT AND OUTPUT LOADING AND FAN-OUT TABLE
PINS
DESCRIPTION
74ALS (U.L.)
HIGH/LOW
LOAD VALUE
HIGH/LOW
A0 A7, B0 B7
Data inputs
1.0/1.0
20
A/0.1mA
OE
Output Enable input (active-Low)
1.0/1.0
20
A/0.1mA
T/R
Transmit/receive input
1.0/1.0
20
A/0.1mA
A0 A7
A port outputs
750/240
15mA/24mA
B0 B7
B port outputs
750/240
15mA/24mA
A0 A7
A port outputs (-1 version)
750/480
15mA/48mA
B0 B7
B port outputs (-1 version)
750/480
15mA/48mA
NOTE:
One (1.0) ALS unit load is defined as: 20
A in the High state and 0.1mA in the Low state.
Philips Semiconductors
Product specification
74ALS245A/74ALS245A-1
Octal transceiver (3-State)
1991 Jun 03
3
LOGIC SYMBOL
B2
B3
B4
B5
16
15
14
13
2
3
4
V
CC
= Pin 20
GND = Pin 10
SF00199
B1
17
B0
18
19
1
OE
T/R
A0
A1
A2
A3
A4
A5
5
6
7
B6
B7
12
11
A6
A7
8
9
IEC/IEEE SYMBOL
SC00097
G3
19
3EN1 [BA]
1
3EN2 [AB]
1
2
2
3
4
5
6
7
8
9
18
17
16
15
14
13
12
11
LOGIC DIAGRAM
SF00201
18
B0
17
B1
16
B2
15
B3
14
B4
13
B5
12
B6
11
B7
A0
A1
A2
A3
A4
A5
A6
A7
2
3
4
5
6
7
8
9
19
1
OE
T/R
V
CC
= Pin 20
GND = Pin 10
FUNCTION TABLE
INPUTS
OUTPUTS
OE
T/R
OUTPUTS
L
L
Bus B data to Bus A
L
H
Bus A data to Bus B
H
X
Z
H = High voltage level
L
= Low voltage level
X = Don't care
Z = High impedance "off" state
Philips Semiconductors
Product specification
74ALS245A/74ALS245A-1
Octal transceiver (3-State)
1991 Jun 03
4
ABSOLUTE MAXIMUM RATINGS
(Operation beyond the limit set forth in this table may impair the useful life of the device.
Unless otherwise noted these limits are over the operating free air temperature range.)
SYMBOL
PARAMETER
RATING
UNIT
V
CC
Supply voltage
0.5 to +7.0
V
V
IN
Input voltage
0.5 to +7.0
V
I
IN
Input current
30 to +5
mA
V
OUT
Voltage applied to output in High output state
0.5 to V
CC
V
I
O
Current applied to output in Low output state
All versions
48
mA
I
OUT
Current applied to output in Low output state
-1 version
96
mA
T
amb
Operating free-air temperature range
0 to +70
C
T
stg
Storage temperature range
65 to +150
C
RECOMMENDED OPERATING CONDITIONS
SYMBOL
PARAMETER
LIMITS
UNIT
SYMBOL
PARAMETER
MIN
NOM
MAX
UNIT
V
CC
Supply voltage
4.5
5.0
5.5
V
V
IH
High-level input voltage
2.0
V
V
IL
Low-level input voltage
0.8
V
I
IK
Input clamp current
18
mA
I
OH
High-level output current
15
mA
I
O
Low level output current
All versions
24
mA
I
OL
Low-level output current
-1 version
48
1
mA
T
amb
Operating free-air temperature range
0
+70
C
NOTES:
1. The 48mA limit applies only under the condition of V
CC
= 5.0V
5%.
Philips Semiconductors
Product specification
74ALS245A/74ALS245A-1
Octal transceiver (3-State)
1991 Jun 03
5
DC ELECTRICAL CHARACTERISTICS
(Over recommended operating free-air temperature range unless otherwise noted.)
SYMBOL
PARAMETER
TEST CONDITIONS
1
LIMITS
UNIT
SYMBOL
PARAMETER
TEST CONDITIONS
1
MIN
TYP
2
MAX
UNIT
V
CC
10%, V
IL
= MAX,
I
OH
= 0.4mA
V
CC
2
V
V
OH
High-level output voltage
CC
,
IL
,
V
IH
= MIN
I
OH
= 3mA
2.4
3.2
V
V
OH
High level out ut voltage
V
CC
= MIN, V
IL
= MAX,
V
IH
= MIN
I
OH
= 15mA
2.0
V
All versions
V
CC
= MIN, V
IL
= MAX,
I
OL
= 12mA
0.25
0.40
V
V
OL
Low-level output voltage
All versions
CC
,
IL
,
V
IH
= MIN
I
OL
= 24mA
0.35
0.50
V
V
OL
Low level out ut voltage
-1 version
V
CC
= 4.75V, V
IL
= MAX,
V
IH
= MIN
I
OL
= 48mA
0.35
0.50
V
V
IK
Input clamp voltage
V
CC
= MIN, I
I
= I
IK
0.73
1.5
V
I
Input current at maxi-
OE or T/R
V
CC
= MAX, V
I
= 7.0V
0.1
mA
I
I
mum input voltage
A or B ports
V
CC
= MAX, V
I
= 5.5V
0.1
mA
I
IH
High-level input current
3
V
CC
= MAX, V
I
= 2.7V
20
A
I
IL
Low-level input current
3
V
CC
= MAX, V
I
= 0.4V
0.1
mA
I
O
Output current
4
V
CC
= MAX, V
O
= 2.25V
30
112
mA
I
CCH
28
45
mA
I
CC
Supply current (total)
I
CCL
V
CC
= MAX
40
55
mA
I
CCZ
44
58
mA
NOTES:
1. For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions for the applicable type.
2. All typical values are at V
CC
= 5V, T
amb
= 25
C.
3. For I/O ports, the parameter I
IH
and I
IL
include the off-state current.
4. The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, I
OS
.
AC ELECTRICAL CHARACTERISTICS
LIMITS
SYMBOL
PARAMETER
TEST CONDITION
T
amb
= 0
C to +70
C
V
CC
= +5.0V
10%
C
L
= 50pF, R
L
= 500
UNIT
MIN
MAX
t
PLH
t
PHL
Propagation delay
An to Bn, Bn to An
Waveform 1
2.0
2.0
10.0
10.0
ns
t
PZH
t
PZL
Output enable time
to High or Low level
Waveform 2
Waveform 3
3.0
3.0
20.0
20.0
ns
t
PHZ
t
PLZ
Output disable time
from High or Low level
Waveform 2
Waveform 3
2.0
4.0
10.0
15.0
ns
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