SN74BCT245N [TI]
OCTAL BUS TRANSCEIVERS WITH 3-STATE OUTPUTS; 八路总线收发器与3态输出
| 型号： | SN74BCT245N |
| 厂家： | 
TEXAS INSTRUMENTS |
| 描述： | OCTAL BUS TRANSCEIVERS WITH 3-STATE OUTPUTS |
| 文件： | 总7页 (文件大小：105K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
SN54BCT245, SN74BCT245
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SCBS013F – SEPTEMBER 1988 – REVISED APRIL 1994
SN54BCT245 . . . J OR W PACKAGE
SN74BCT245 . . . DB, DW, OR N PACKAGE
(TOP VIEW)
• State-of-the-Art BiCMOS Design
Significantly Reduces I
CCZ
• ESD Protection Exceeds 2000 V
Per MIL-STD-883C, Method 3015
DIR
A1
V
CC
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
• 3-State Outputs Drive Bus Lines or Buffer
OE
B1
B2
B3
B4
B5
Memory Address Registers
A2
A3
A4
A5
• Package Options Include Plastic
Small-Outline (DW) and Shrink
Small-Outline (DB) Packages, Ceramic Chip
Carriers (FK) and Flatpacks (W), and
Standard Plastic and Ceramic 300-mil DIPs
(J, N)
A6
A7
A8
13 B6
12 B7
11
GND
B8
description
SN54BCT245 . . . FK PACKAGE
(TOP VIEW)
These octal bus transceivers are designed for
asynchronous communication between data
buses. The devices transmit data from the A bus
to the B bus or from the B bus to the A bus
depending upon the level at the direction-control
(DIR) input. The output-enable (OE) input can be
used to disable the device so the buses are
effectively isolated.
3
2
1
20 19
18
B1
17 B2
A3
A4
A5
A6
A7
4
5
6
7
8
16
15
14
B3
B4
B5
The SN74BCT245 is available in TI’s shrink
small-outline package (DB), which provides the
same I/O pin count and functionality of standard
small-outline packages in less than half the
printed-circuit-board area.
9 10 11 12 13
The SN54BCT245 is characterized for operation
over the full military temperature range of –55°C
to 125°C. The SN74BCT245 is characterized for
operation from 0°C to 70°C.
FUNCTION TABLE
INPUTS
OPERATION
OE
DIR
L
L
L
B data to A bus
A data to B bus
Isolation
H
H
X
Copyright 1994, 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.
2–1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
SN54BCT245, SN74BCT245
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SCBS013F – SEPTEMBER 1988 – REVISED APRIL 1994
†
logic symbol
logic diagram (positive logic)
19
1
DIR
G3
OE
1
DIR
3EN1[BA]
3EN2[AB]
19
18
OE
B1
2
18
A1
B1
1
2
A1
2
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
To Seven Other Channels
†
This symbol is in accordance with ANSI/IEEE Std 91-1984
and IEC Publication 617-12.
‡
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
Supply voltage range, V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.5 V to 7 V
CC
Input voltage range: Control inputs (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.5 V to 7 V
I/O ports (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.5 V to 5.5 V
Voltage range applied to any output in the disabled or power-off state, V . . . . . . . . . . . . . . . . . – 0.5 V to 7 V
O
Voltage range applied to any output in the high state, V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.5 V to V
O
CC
Current into any output in the low state: SN54BCT245 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 mA
SN74BCT245 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 mA
Power dissipation (DB package only) (see Note 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 650 mW
Operating free-air temperature range: SN54BCT245 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 55°C to 125°C
SN74BCT245 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C
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.
NOTES: 1. The input and output voltage ratings may be exceeded if the input and output current ratings are observed.
2. Power dissipation is application dependent and is a function of supply voltage, operating temperature, the number of outputs
switching simultaneously, and output duty cycle. Because the thermal resistance of the DB package is higher than that of the DW
or N packages, the DB package may not be suitable for some applications.
2–2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
SN54BCT245, SN74BCT245
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SCBS013F – SEPTEMBER 1988 – REVISED APRIL 1994
recommended operating conditions
SN54BCT245
SN74BCT245
MIN NOM MAX
UNIT
MIN NOM
MAX
V
V
V
Supply voltage
4.5
2
5
5.5
4.5
2
5
5.5
V
V
CC
IH
IL
High-level input voltage
Low-level input voltage
Input clamp current
0.8
–18
–3
0.8
–18
–3
V
I
IK
mA
A port
B port
A port
B port
I
High-level output current
mA
OH
OL
–12
20
–15
24
I
Low-level output current
mA
48
64
T
A
Operating free-air temperature
–55
125
0
70
°C
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
SN54BCT245
SN74BCT245
PARAMETER
TEST CONDITIONS
UNIT
†
†
MIN TYP
MAX
MIN TYP
MAX
V
V
V
= 4.5 V,
= 4.5 V
I = –18 mA
–1.2
–1.2
V
IK
CC
I
I
I
I
I
I
I
I
I
I
= –1 mA
= –3 mA
= –3 mA
= –12 mA
= –15 mA
= 20 mA
= 24 mA
= 48 mA
= 64 mA
2.5
2.4
2.4
2
3.4
3.3
3.3
3.2
2.5
2.4
2.4
3.4
3.3
3.3
OH
OH
OH
OH
OH
OL
OL
OL
OL
A port
B port
CC
V
OH
V
V
V
CC
= 4.5 V
2
3.1
0.35
0.42
0.3
0.5
A port
B port
V
CC
V
CC
V
CC
V
CC
V
CC
V
CC
= 4.5 V
= 4.5 V
= 5.5 V,
= 5.5 V,
= 5.5 V,
= 5.5 V,
0.5
V
OL
0.38
0.55
0.55
1
A or B port
Control input
A or B port
Control input
A or B port
Control input
A port
1
0.1
V = 5.5 V
I
mA
µA
I
I
0.1
70
70
‡
V = 2.7 V
I
I
IH
20
20
–0.65
–1.2
–150
–225
90
–0.65
–1.2
–150
–225
90
‡
V = 0.5 V
I
mA
mA
I
IL
–60
–60
§
V
O
= 0
I
OS
B port
–100
–100
I
I
I
A to B
V
CC
V
CC
V
CC
V
CC
= 5.5 V
= 5.5 V
= 5.5 V
= 5 V,
57
36
10
7
57
36
10
7
mA
mA
mA
pF
CCL
CCH
CCZ
A to B
57
57
15
15
C
Control input
A to B
V = 2.5 V or 0.5 V
I
i
9
9
C
V
CC
= 5 V,
V = 2.5 V or 0.5 V
O
pF
io
B to A
12
12
†
‡
§
All typical values are at V
For I/O ports, the parameters I and I include the off-state output current.
Not more than one output should be tested at a time, and the duration of the test should not exceed one second.
= 5 V, T = 25°C.
A
CC
IH
IL
2–3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
SN54BCT245, SN74BCT245
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SCBS013F – SEPTEMBER 1988 – REVISED APRIL 1994
switching characteristics (see Note 3)
V
C
= 5 V,
= 50 pF,
V
= 4.5 V to 5.5 V,
C = 50 pF,
L
CC
L
CC
R1 = 500 Ω,
R2 = 500 Ω,
T
A
R1 = 500 Ω,
R2 = 500 Ω,
†
T = MIN to MAX
A
FROM
(INPUT)
TO
(OUTPUT)
PARAMETER
UNIT
= 25°C
′BCT245
TYP
4.4
SN54BCT245 SN74BCT245
MIN
1
MAX
6
MIN
1
MAX
7.2
MIN
1
MAX
7
t
t
t
t
t
t
PLH
PHL
PZH
PZL
PHZ
PLZ
A or B
B or A
A or B
A or B
ns
ns
ns
1.5
1.5
1.5
1.5
1.5
4.8
6.6
9.4
10.2
8.3
7.8
1.5
1.5
1.5
1.5
1.5
7.6
1.5
1.5
1.5
1.5
1.5
7
8
11.2
11.8
9.7
10.9
11.6
9.3
9.1
OE
OE
8
5.8
5.1
9.6
†
For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
NOTE 3: Load circuits and voltage waveforms are shown in Section 1.
2–4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
SN54BCT245, SN74BCT245
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SCBS013F – SEPTEMBER 1988 – REVISED APRIL 1994
†
TYPICAL CHARACTERISTICS
Figures 1 through 4 show the typical power dissipation for an SN74BCT245 over variations in outputs switching,
output frequency, and capacitive load.
POWER DISSIPATION
vs
POWER DISSIPATION
vs
FREQUENCY
FREQUENCY
1050
900
1400
1200
V
T
R
= 5.5 V
Eight Switching
V
= 5.5 V
CC
= 70°C
A
L
CC
= 70°C
T
A
= 500 Ω
R
= 500 Ω
Eight Switching
L
Air Flow = 0
= 50 pF
Air Flow = 0
C = 15 pF
750
1000
800
600
400
C
L
L
Four Switching
One Switching
600
450
300
Four Switching
One Switching
150
0
200
0
0
10
20
30
40
50
10
20
30
40
50
0
f – Frequency – MHz
f – Frequency – MHz
Figure 1
Figure 2
POWER DISSIPATION
vs
POWER DISSIPATION
vs
FREQUENCY
FREQUENCY
1750
1750
1500
Eight Switching
Four Switching
V
T
R
= 5.5 V
= 70°C
= 500 Ω
Eight Switching
V
CC
= 5.5 V
= 70°C
CC
A
L
T
A
L
1500
1250
1000
750
R
= 500 Ω
Air Flow = 0
= 150 pF
Air Flow = 0
= 100 pF
1250
1000
750
C
C
L
L
Four Switching
One Switching
One Switching
500
500
250
0
250
0
0
10
20
30
40
50
0
10
20
30
40
50
f – Frequency – MHz
f – Frequency – MHz
Figure 3
Figure 4
†
The dashed lines are for the DB package only.
2–5
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
2–6
IMPORTANT NOTICE
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any product or service without notice, and advise customers to obtain the latest version of relevant information
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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.
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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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