INTEGRATED CIRCUITS
74ALS245A/74ALS245A–1
Octal transceiver (3–State)
Product specification
IC05 Data Handbook
1991 Jun 03
Philips
Semiconductors
Philips Semiconductors
Product specification
Octal transceiver (3-State)
74ALS245A/74ALS245A-1
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
PIN CONFIGURATION
T/R 1
A0
A1
A2
A3
2
3
4
5
6
7
8
9
20 V
CC
19 OE
18 B0
17 B1
16 B2
15 B3
14 B4
13 B5
12 B6
11 B7
•
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.
TYPICAL
PROPAGATION
DELAY
7.0ns
7.0ns
TYPICAL
SUPPLY CURRENT
(TOTAL)
34mA
34mA
20-pin plastic DIP
20-pin plastic SOL
20-pin plastic SSOP
Type II
A4
A5
A6
A7
GND 10
SF00198
ORDERING INFORMATION
ORDER CODE
DESCRIPTION
COMMERCIAL RANGE
V
CC
= 5V
±10%,
T
amb
= 0°C to +70°C
74ALS245AN,
74ALS245A-1N
74ALS245AD,
744ALS245A-1D
74ALS245ADB,
74ALS245A-1DB
DRAWING
NUMBER
TYPE
74ALS245A
74ALS245A-1
SOT146-1
SOT163-1
SOT339-1
INPUT AND OUTPUT LOADING AND FAN-OUT TABLE
PINS
A0 – A7, B0 – B7
OE
T/R
A0 – A7
B0 – B7
A0 – A7
B0 – B7
DESCRIPTION
Data inputs
Output Enable input (active-Low)
Transmit/receive input
A port outputs
B port outputs
A port outputs (-1 version)
B port outputs (-1 version)
74ALS (U.L.)
HIGH/LOW
1.0/1.0
1.0/1.0
1.0/1.0
750/240
750/240
750/480
750/480
LOAD VALUE
HIGH/LOW
20µA/0.1mA
20µA/0.1mA
20µA/0.1mA
15mA/24mA
15mA/24mA
15mA/48mA
15mA/48mA
NOTE:
One (1.0) ALS unit load is defined as: 20µA in the High state and 0.1mA in the Low state.
1991 Jun 03
2
853–0011 02709
Philips Semiconductors
Product specification
Octal transceiver (3-State)
74ALS245A/74ALS245A-1
LOGIC SYMBOL
IEC/IEEE SYMBOL
19
G3
3EN1 [BA]
1
3EN2 [AB]
2
3
4
5
6
7
8
9
A0
19
1
OE
T/R
B0
A1
A2
A3
A4
A5
A6
A7
2
3
4
∇
1
2
∇
18
17
16
15
14
13
12
11
B1
B2
B3
B4
B5
B6
B7
5
6
7
18
V
CC
= Pin 20
GND = Pin 10
17
16
15
14
13
12
11
8
9
SF00199
SC00097
LOGIC DIAGRAM
A0
2
A1
3
A2
4
A3
5
A4
6
A5
7
A6
8
A7
9
OE
19
1
18
B0
17
B1
16
B2
15
B3
14
B4
13
B5
12
B6
11
B7
T/R
V
CC
= Pin 20
GND = Pin 10
SF00201
FUNCTION TABLE
INPUTS
OE
L
L
H
H
L
X
Z
=
=
=
=
T/R
L
H
X
OUTPUTS
Bus B data to Bus A
Bus A data to Bus B
Z
High voltage level
Low voltage level
Don’t care
High impedance “off” state
1991 Jun 03
3
Philips Semiconductors
Product specification
Octal transceiver (3-State)
74ALS245A/74ALS245A-1
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
V
CC
V
IN
I
IN
V
OUT
I
O
OUT
T
amb
T
stg
Supply voltage
Input voltage
Input current
Voltage applied to output in High output state
Current applied to output in Low output state
Operating free-air temperature range
Storage temperature range
All versions
-1 version
PARAMETER
RATING
–0.5 to +7.0
–0.5 to +7.0
–30 to +5
–0.5 to V
CC
48
96
0 to +70
–65 to +150
UNIT
V
V
mA
V
mA
mA
°C
°C
RECOMMENDED OPERATING CONDITIONS
SYMBOL
V
CC
V
IH
V
IL
I
IK
I
OH
I
O
OL
T
amb
Supply voltage
High-level input voltage
Low-level input voltage
Input clamp current
High-level output current
Low-level
Low level output current
Operating free-air temperature range
All versions
-1 version
0
LIMITS
PARAMETER
MIN
4.5
2.0
0.8
–18
–15
24
48
1
+70
NOM
5.0
MAX
5.5
UNIT
V
V
V
mA
mA
mA
mA
°C
NOTES:
1. The 48mA limit applies only under the condition of V
CC
= 5.0V
±
5%.
1991 Jun 03
4
Philips Semiconductors
Product specification
Octal transceiver (3-State)
74ALS245A/74ALS245A-1
DC ELECTRICAL CHARACTERISTICS
(Over recommended operating free-air temperature range unless otherwise noted.)
SYMBOL
PARAMETER
TEST CONDITIONS
1
V
CC
±10%,
V
IL
= MAX,
,
,
V
IH
= MIN
V
CC
= MIN, V
IL
= MAX,
V
IH
= MIN
All versions
V
OL
Low-level out ut voltage
Low level output
-1 version
V
IK
I
I
I
IH
I
IL
I
O
I
CC
Input clamp voltage
Input current at maxi-
mum input voltage
High-level input
Output current
4
I
CCH
Supply current (total)
I
CCL
I
CCZ
V
CC
= MAX
current
3
OE or T/R
A or B ports
V
CC
= MIN, V
IL
= MAX,
,
,
V
IH
= MIN
V
CC
= 4.75V, V
IL
= MAX,
V
IH
= MIN
V
CC
= MIN, I
I
= I
IK
V
CC
= MAX, V
I
= 7.0V
V
CC
= MAX, V
I
= 5.5V
V
CC
= MAX, V
I
= 2.7V
V
CC
= MAX, V
I
= 0.4V
V
CC
= MAX, V
O
= 2.25V
–30
28
40
44
I
OH
= –0.4mA
I
OH
= –3mA
I
OH
= –15mA
I
OL
= 12mA
I
OL
= 24mA
I
OL
= 48mA
LIMITS
MIN
V
CC
– 2
2.4
2.0
0.25
0.35
0.35
–0.73
0.40
0.50
0.50
–1.5
0.1
0.1
20
–0.1
–112
45
55
58
3.2
TYP
2
MAX
UNIT
V
V
V
V
V
V
V
mA
mA
µA
mA
mA
mA
mA
mA
V
OH
High level output
High-level out ut voltage
Low-level input current
3
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
= 500Ω
MIN
t
PLH
t
PHL
t
PZH
t
PZL
t
PHZ
t
PLZ
Propagation delay
An to Bn, Bn to An
Output enable time
to High or Low level
Output disable time
from High or Low level
Waveform 1
Waveform 2
Waveform 3
Waveform 2
Waveform 3
2.0
2.0
3.0
3.0
2.0
4.0
MAX
10.0
10.0
20.0
20.0
10.0
15.0
ns
ns
ns
UNIT
1991 Jun 03
5
嵌入式系统
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