SN74AS638A [TI]
OCTAL BUS TRANSCEIVERS; 八路总线收发器
| 型号： | SN74AS638A |
| 厂家： | 
TEXAS INSTRUMENTS |
| 描述： | OCTAL BUS TRANSCEIVERS |
| 文件： | 总7页 (文件大小：118K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
SN74ALS638A, SN74ALS639A, SN74AS638A, SN74AS639
OCTAL BUS TRANSCEIVERS
SDAS123A – DECEMBER 1983 – REVISED JANUARY 1995
DW OR N PACKAGE
(TOP VIEW)
• Bidirectional Bus Transceivers in
High-Density 20-Pin Packages
• Choice of True or Inverting Logic
DIR
A1
A2
A3
A4
A5
A6
A7
A8
V
CC
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
• A-Bus Outputs Are Open Collector;
OE
B1
B2
B3
B4
B5
B-Bus Outputs Are 3 State
• Package Options Include Plastic
Small-Outline (DW) Packages and
Standard Plastic (N) 300-mil DIPs
A
B
13 B6
12 B7
DEVICE
LOGIC
OUTPUT
OUTPUT
SN74ALS638A, SN74AS638A Open collector
3 state
Inverting
True
11
GND
B8
SN74ALS639A, SN74AS639
Open collector
3 state
description
These octal bus transceivers are designed for asynchronous two-way communication between open-collector
and 3-state buses. The devices transmit data from the A bus (open-collector) to the B bus (3 state) or from the
B bus to the A bus, depending on the logic level at the direction-control (DIR) input. The output-enable (OE) input
can be used to disable the device so the buses are isolated.
The -1 version of SN74ALS638A is identical to the standard version, except that the recommended maximum
I
is increased to 48 mA.
OL
The SN74ALS638A, SN74ALS639A, SN74AS638A, and SN74AS639 are characterized for operation from 0°C
to 70°C.
FUNCTION TABLE
INPUTS
OPERATION
SN74ALS638A
SN74ALS639A
SN74AS639
OE
DIR
SN74AS638A
B data to A bus
A data to B bus
Isolation
L
L
L
H
X
B data to A bus
A data to B bus
Isolation
H
Copyright 1995, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
SN74ALS638A, SN74ALS639A, SN74AS638A, SN74AS639
OCTAL BUS TRANSCEIVERS
SDAS123A – DECEMBER 1983 – REVISED JANUARY 1995
†
logic symbols
SN74ALS638A, SN74AS638A
SN74ALS639A, SN74AS639
G3
19
1
19
1
G3
OE
OE
DIR
3 EN1 [BA]
3 EN2 [AB]
DIR
3 EN1 [BA]
3 EN2 [AB]
2
18
2
18
A1
B1
A1
B1
1
1
2
2
3
4
5
6
7
8
9
17
16
15
14
13
12
11
3
4
5
6
7
8
9
17
16
15
14
13
12
11
A2
A3
A4
A5
A6
A7
A8
B2
B3
B4
B5
B6
B7
B8
A2
A3
A4
A5
A6
A7
A8
B2
B3
B4
B5
B6
B7
B8
†
These symbols are in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
logic diagrams (positive logic)
SN74ALS638A, SN74AS638A
SN74ALS639A, SN74AS639
19
19
OE
OE
1
1
2
DIR
DIR
A1
2
18
18
A1
B1
B1
To Seven Other Transceivers
To Seven Other Transceivers
‡
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
Supply voltage, V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
CC
Input voltage, V : All inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
I
A-bus I/O ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
B-bus I/O ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 V
Operating free-air temperature range, T : SN74ALS638A, SN74ALS639A . . . . . . . . . . . . . . . . . 0°C to 70°C
A
Storage temperature range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65°C to 150°C
‡
Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
SN74ALS638A, SN74ALS639A, SN74AS638A, SN74AS639
OCTAL BUS TRANSCEIVERS
SDAS123A – DECEMBER 1983 – REVISED JANUARY 1995
recommended operating conditions
SN74ALS638A
SN74ALS639A
UNIT
MIN NOM
MAX
V
V
V
V
Supply voltage
4.5
2
5
5.5
V
V
CC
High-level input voltage
Low-level input voltage
High-level output voltage
High-level output current
IH
0.8
5.5
–15
24
V
IL
A ports
B ports
V
OH
I
mA
OH
I
Low-level output current
A or B ports
mA
OL
†
48
70
T
A
Operating free-air temperature
0
°C
†
Applies only to the SN74ALS638A-1 version and only if V
is between 4.75 V and 5.25 V
CC
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
SN74ALS638A
SN74ALS639A
PARAMETER
TEST CONDITIONS
UNIT
‡
MIN TYP
MAX
–1.5
0.1
V
V
V
V
= 4.5 V,
I = –18 mA
V
IK
CC
CC
CC
I
I
A ports
B ports
= 4.5 V,
V
OH
= 5.5 V
mA
OH
= 4.5 V to 5.5 V,
I
I
I
I
I
I
= –0.4 mA
= –3 mA
= –15 mA
= 12 mA
V
–2
OH
OH
OH
OL
OL
OL
CC
2.4
V
V
3.2
V
V
OH
V
CC
= 4.5 V
= 4.5 V
2
0.25
0.35
0.35
0.4
0.5
0.5
0.1
0.1
20
A or B ports
V
CC
= 24 mA
OL
†
= 48 mA
Control inputs
A or B ports
V = 7 V
I
I
I
V
V
= 5.5 V
= 5.5 V,
mA
I
CC
V = 5.5 V
I
Control inputs
V = 2.7 V
I
µA
IH
CC
§
A or B ports
20
Control inputs
–0.1
–0.1
–112
30
I
I
V
V
= 5.5 V,
= 5.5 V,
V = 0.4 V
mA
mA
IL
CC
I
§
A or B ports
¶
B ports
V
O
= 2.25 V
–30
O
CC
Outputs high
Outputs low
18
26
16
25
30
33
SN74ALS638A
SN74ALS639A
V
V
= 5.5 V
= 5.5 V
41
CC
Outputs disabled
Outputs high
30
I
mA
CC
40
Outputs low
50
CC
Outputs disabled
is between 4.75 V and 5.25 V
54
†
Applies only to the SN74ALS638A-1 version and only if V
All typical values are at V
CC
For I/O ports, the parameters I and I include the off-state output current.
CC
‡
§
¶
= 5 V, T = 25°C.
A
IH
IL
The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, I
.
OS
3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
SN74ALS638A, SN74ALS639A, SN74AS638A, SN74AS639
OCTAL BUS TRANSCEIVERS
SDAS123A – DECEMBER 1983 – REVISED JANUARY 1995
switching characteristics (see Figure 1)
V
C
R
= 4.5 V to 5.5 V,
= 50 pF,
= 680 Ω (A outputs),
CC
L
L
FROM
(INPUT)
TO
(OUTPUT)
R1 = R2 = 500 Ω (B outputs),
T
A
PARAMETER
UNIT
†
= MIN to MAX
SN74ALS638A SN74ALS639A
MIN
2
MAX
12
12
25
30
25
45
20
22
10
15
MIN
2
MAX
12
12
30
22
30
35
21
25
10
16
t
t
t
t
t
t
t
t
t
t
PLH
PHL
PLH
PHL
PLH
PHL
PZH
PZL
PHZ
PLZ
A
B
ns
ns
ns
ns
ns
B
A
A
B
B
2
2
8
10
5
8
5
10
10
6
OE
OE
OE
10
5
5
8
2
2
3
3
†
For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
‡
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
Supply voltage, V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
CC
Input voltage, V : All inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
I
A-bus I/O ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
B-bus I/O ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 V
Operating free-air temperature range, T : SN74AS638A, SN74AS639 . . . . . . . . . . . . . . . . . . . . 0°C to 70°C
A
Storage temperature range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65°C to 150°C
‡
Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
recommended operating conditions
SN74AS638A
SN74AS639
UNIT
MIN NOM
MAX
V
V
V
V
Supply voltage
4.5
2
5
5.5
V
V
CC
High-level input voltage
Low-level input voltage
High-level output voltage
High-level output current
Low-level output current
Operating free-air temperature
IH
0.8
5.5
–15
64
V
IL
A ports
V
OH
I
I
B ports
mA
mA
°C
OH
A or B ports
OL
T
A
0
70
4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
SN74ALS638A, SN74ALS639A, SN74AS638A, SN74AS639
OCTAL BUS TRANSCEIVERS
SDAS123A – DECEMBER 1983 – REVISED JANUARY 1995
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
SN74AS638A
SN74AS639
PARAMETER
TEST CONDITIONS
UNIT
†
MIN TYP
MAX
–1.2
0.1
V
V
V
V
= 4.5 V,
I = –18 mA
V
IK
CC
CC
CC
I
I
A ports
B ports
= 4.5 V,
V
OH
= 5.5 V
mA
OH
= 4.5 V to 5.5 V,
I
I
I
I
= –2 mA
= –3 mA
= –15 mA
= 64 mA
V
–2
OH
OH
OH
OL
CC
2.4
V
3.2
V
OH
OL
V
CC
V
CC
V
CC
= 4.5 V
= 4.5 V,
= 5.5 V
2.4
V
A or B ports
Control inputs
A or B ports
Control inputs
0.35
0.55
0.1
V
V = 7 V
I
I
I
mA
I
V = 5.5 V
I
0.1
20
V
CC
= 5.5 V,
V = 2.7 V
I
µA
IH
‡
A or B ports
Control inputs
70
–0.5
–0.75
–150
54
I
I
V
V
= 5.5 V,
= 5.5 V,
V = 0.4 V
I
mA
mA
IL
CC
‡
A or B ports
§
V
O
= 2.25 V
–50
O
CC
Outputs high
Outputs low
24
75
37
56
95
62
SN74AS638A
SN74AS639
V
= 5.5 V
= 5.5 V
122
61
CC
CC
Outputs disabled
Outputs high
Outputs low
I
mA
CC
92
V
154
100
Outputs disabled
†
‡
§
All typical values are at V
For I/O ports, the parameters I and I include the off-state output current.
The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, I
= 5 V, T = 25°C.
A
IH IL
CC
.
OS
switching characteristics (see Figure 1)
V
C
R
= 4.5 V to 5.5 V,
= 50 pF,
= 500 Ω (A outputs),
CC
L
L
FROM
TO
(OUTPUT)
R1 = R2 = 500 Ω (B outputs),
T
A
PARAMETER
(INPUT)
UNIT
¶
= MIN to MAX
SN74AS638A
SN74AS639
MIN
2
MAX
7
MIN
2
MAX
9.5
9
t
t
t
t
t
t
t
t
t
t
PLH
PHL
PLH
PHL
PLH
PHL
PZH
PZL
PHZ
PLZ
A
B
ns
ns
ns
ns
ns
B
A
A
B
B
2
6.5
20
7
2
5
5
22
2
2
9
5
19
9
5
21.5
11.5
10.5
10.5
7
OE
OE
OE
2
2
2
8
2
2
10
7
2
2
2
2
10
2
10.5
¶
For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
5
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
SN74ALS638A, SN74ALS639A, SN74AS638A, SN74AS639
OCTAL BUS TRANSCEIVERS
SDAS123A – DECEMBER 1983 – REVISED JANUARY 1995
PARAMETER MEASUREMENT INFORMATION
SERIES 54ALS/74ALS AND 54AS/74AS DEVICES
7 V
R
= R1 = R2
V
CC
L
S1
R1
R
L
Test
Point
From Output
Under Test
From Output
Under Test
Test
Point
Test
Point
From Output
Under Test
C
C
L
R
L
R2
L
C
L
(see Note A)
(see Note A)
(see Note A)
LOAD CIRCUIT FOR
BI-STATE
TOTEM-POLE OUTPUTS
LOAD CIRCUIT
FOR OPEN-COLLECTOR OUTPUTS
LOAD CIRCUIT
FOR 3-STATE OUTPUTS
3.5 V
3.5 V
Timing
Input
High-Level
1.3 V
1.3 V
1.3 V
Pulse
0.3 V
0.3 V
t
h
t
w
t
su
3.5 V
3.5 V
0.3 V
Data
Input
Low-Level
1.3 V
1.3 V
1.3 V
1.3 V
Pulse
0.3 V
VOLTAGE WAVEFORMS
SETUP AND HOLD TIMES
VOLTAGE WAVEFORMS
PULSE DURATIONS
3.5 V
0.3 V
Output
Control
(low-level
enabling)
1.3 V
1.3 V
3.5 V
t
PZL
Input
1.3 V
1.3 V
t
PLZ
0.3 V
PHL
3.5 V
t
Waveform 1
S1 Closed
(see Note B)
t
PLH
1.3 V
V
OH
In-Phase
Output
1.3 V
1.3 V
1.3 V
V
OL
0.3 V
V
OL
t
PHZ
t
PLH
t
PZH
t
PHL
V
OH
V
Waveform 2
S1 Open
(see Note B)
OH
OL
Out-of-Phase
Output
(see Note C)
1.3 V
1.3 V
0.3 V
V
0 V
VOLTAGE WAVEFORMS
PROPAGATION DELAY TIMES
VOLTAGE WAVEFORMS
ENABLE AND DISABLE TIMES, 3-STATE OUTPUTS
NOTES: A.
C includes probe and jig capacitance.
L
B. Waveform 1 is for an output with internal conditions such that the output is low except when disabled by the output control.
Waveform 2 is for an output with internal conditions such that the output is high except when disabled by the output control.
C. When measuring propagation delay items of 3-state outputs, switch S1 is open.
D. All input pulses have the following characteristics: PRR ≤ 1 MHz, t = t = 2 ns, duty cycle = 50%.
r
f
E. The outputs are measured one at a time with one transition per measurement.
Figure 1. Load Circuits and Voltage Waveforms
6
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
IMPORTANT NOTICE
Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue
any product or service without notice, and advise customers to obtain the latest version of relevant information
to verify, before placing orders, that information being relied on is current and complete. All products are sold
subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those
pertaining to warranty, patent infringement, and limitation of liability.
TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in
accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent
TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily
performed, except those mandated by government requirements.
CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF
DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL
APPLICATIONS”). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, AUTHORIZED, OR
WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT DEVICES OR SYSTEMS OR OTHER
CRITICAL APPLICATIONS. INCLUSION OF TI PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO
BE FULLY AT THE CUSTOMER’S RISK.
In order to minimize risks associated with the customer’s applications, adequate design and operating
safeguards must be provided by the customer to minimize inherent or procedural hazards.
TI assumes no liability for applications assistance or customer product design. TI does not warrant or represent
that any license, either express or implied, is granted under any patent right, copyright, mask work right, or other
intellectual property right of TI covering or relating to any combination, machine, or process in which such
semiconductor products or services might be or are used. TI’s publication of information regarding any third
party’s products or services does not constitute TI’s approval, warranty or endorsement thereof.
Copyright 1998, Texas Instruments Incorporated
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