Texas Instruments SN54ALS245AJ, SN54AS245J, SN74ALS245A-1DW, SN74ALS245A-1DWR, SN74ALS245A-1N Datasheet
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OPERATION
SN54ALS245A, SN54AS245, SN74ALS245A, SN74AS245
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SDAS272 – NOVEMBER 1994
• 3-State Outputs Drive Bus Lines Directly
• pnp Inputs Reduce dc Loading
• Package Options Include Plastic
Small-Outline (DW) Packages, Ceramic
Chip Carriers (FK), and Standard Plastic (N)
and Ceramic (J) 300-mil DIPs
description
These octal bus transceivers are designed for
asynchronous two-way communication between
data buses. The control-function implementation
minimizes external timing requirements.
The devices allow data transmission from the
A bus to the B bus or from the B bus to the A bus
depending upon the logic level at the
direction-control (DIR) input. The output-enable
(OE
) input can be used to disable the device so
that the buses are effectively isolated.
The -1 version of the SN74ALS245A is identical to
the standard version, except that the
recommended maximum I
48 mA. There is no -1 version of the
SN54ALS245A.
The SN54ALS245A and SN54AS245 are
characterized for operation over the full military
temperature range of –55°C to 125°C. The
SN74ALS245A and SN74AS245 are
characterized for operation from 0°C to 70°C.
is increased to
OL
SN54ALS245A, SN54AS245 ...J PACKAGE
SN74ALS245A, SN74AS245 . . . DW OR N PACKAGE
SN54ALS245A, SN54AS245 . . . FK PACKAGE
A3
A4
A5
A6
A7
(TOP VIEW)
1
DIR
2
A1
3
A2
4
A3
5
A4
6
A5
7
A6
8
A7
9
A8
10
GND
(TOP VIEW)
A2A1DIR
3212019
4
5
6
7
8
910111213
A8
B8
20
19
18
17
16
15
14
13
12
11
CC
V
B7
V
OE
B1
B2
B3
B4
B5
B6
B7
B8
OE
18
17
16
15
14
B6
CC
B1
B2
B3
B4
B5
GND
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.
FUNCTION TABLE
INPUTS
OE DIR
L L B data to A bus
L H A data to B bus
H X Isolation
Copyright 1994, Texas Instruments Incorporated
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
1
SN54ALS245A, SN54AS245, SN74ALS245A, SN74AS245
UNIT
IOLLow-level output current
mA
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SDAS272 – NOVEMBER 1994
19
1
2
3
4
5
6
7
8
9
†
G3
3EN1[BA]
3EN2[AB]
1
2
18
17
16
15
14
13
12
11
logic diagram (positive logic)
1
DIR
B1
B2
B3
B4
B5
B6
B7
B8
A1
2
To Seven Other Channels
19
18
OE
B1
logic symbol
OE
DIR
A1
A2
A3
A4
A5
A6
A7
A8
†
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, V
Input voltage, V
Operating free-air temperature range, T
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.
7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CC
: All inputs 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I
I/O ports 5.5 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
: SN54ALS245A –55°C to 125°C. . . . . . . . . . . . . . . . . . . . . . . . . . .
A
SN74ALS245A 0°C to 70°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
‡
recommended operating conditions
V
CC
V
IH
V
IL
I
OH
T
A
§
Applies only to the -1 version and only if VCC is between 4.75 V and 5.25 V
2
SN54ALS245A SN74ALS245A
MIN NOM MAX MIN NOM MAX
Supply voltage 4.5 5 5.5 4.5 5 5.5 V
High-level input voltage 2 2 V
Low-level input voltage 0.7 0.8 V
High-level output current –12 –15 mA
p
Operating free-air temperature –55 125 0 70 °C
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
12 24
48
§
PARAMETER
TEST CONDITIONS
UNIT
V
V
I
V
V
mA
I
V
V
V
A
I
V
V
V
mA
A or B
B or A
ns
OE
A or B
ns
OE
A or B
ns
SN54ALS245A, SN54AS245, SN74ALS245A, SN74AS245
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SDAS272 – NOVEMBER 1994
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
SN54ALS245A SN74ALS245A
MIN TYP†MAX MIN TYP†MAX
V
IK
OH
V
OL
I
IH
IL
I
O
I
CC
†
All typical values are VCC = 5 V, TA = 25°C.
‡
Applies only to the -1 version and only if VCC is between 4.75 V and 5.25 V
§
For I/O ports, the parameters IIH and IIL 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, IOS.
Control inputs
A or B ports
Control inputs
A or B ports
Control inputs
A or B ports
¶
VCC = 4.5 V, II = –18 mA –1.5 –1.5 V
VCC = 4.5 V to 5.5 V, IOH = –0.4 mA VCC –2 VCC –2
IOH = –3 mA 2.4 3.2 2.4 3.2
VCC = 4.5 V
VCC = 4.5 V
= 5.5
CC
= 5.5 V,
§
§
CC
= 5.5 V,
CC
VCC = 5.5 V, VO = 2.25 V –20 –112 –30 –112 mA
VCC = 5.5 V
IOH = –12 mA 2
IOH = –15 mA 2
IOL= 12 mA 0.25 0.4 0.25 0.4
IOL = 24 mA
IOL = 48 mA
VI = 7 V 0.1 0.1
VI = 5.5 V 0.1 0.1
= 2.7
I
= 0.4
I
Outputs high 30 48 30 45
Outputs low 36 60 36 55
Outputs disabled 38 63 38 58
‡
20 20
20 20
–0.1 –0.1
–0.1 –0.1
0.35 0.5
0.35 0.5
V
µ
mA
switching characteristics (see Figure 1)
VCC = 4.5 V to 5.5 V,
CL = 50 pF,
PARAMETER
t
PLH
t
PHL
t
PZH
t
PZL
t
PHZ
t
PLZ
#
For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
FROM
(INPUT)
TO
(OUTPUT)
R1 = 500 Ω,
R2 = 500 Ω,
TA = MIN to MAX
SN54ALS245A SN74ALS245A
MIN MAX MIN MAX
1 19 3 10
1 14 3 10
2 30 5 20
2 29 5 20
2 14 2 10
2 30 4 15
#
UNIT
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
3
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