SN54ALS645A, SN54AS645, SN74ALS645A, SN74AS645
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SDAS278 – JANUARY 1995
•
•
•
Bidirectional Bus Transceivers in
High-Density 20-Pin Packages
True Logic
3-State Outputs
Package Options Include Plastic
Small-Outline (DW) Packages, Ceramic
Chip Carriers (FK), and Standard Plastic (N)
and Ceramic (J) 300-mil DIPs
SN54ALS645A, SN54AS645 . . . J PACKAGE
SN74ALS645A, SN74AS645 . . . DW OR N PACKAGE
(TOP VIEW)
DIR
A1
A2
A3
A4
A5
A6
A7
A8
GND
description
These octal bus transceivers are designed for
asynchronous two-way communication between
data buses. These devices transmit data from the
A bus to the B bus or from the B bus to the A bus,
depending on the 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.
1
20
2
19
3
18
4
17
5
16
6
15
7
14
8
13
9
12
10
11
VCC
OE
B1
B2
B3
B4
B5
B6
B7
B8
A2
A1
DIR
VCC
SN54ALS645A, SN54AS645 . . . FK PACKAGE
(TOP VIEW)
The -1 version of the SN74ALS645A is identical
to the standard version, except that the
recommended maximum IOL is increased to
48 mA. There is no -1 version of the
SN54ALS645A.
A3
A4
A5
A6
A7
The SN54ALS645A and SN54AS645 are
characterized for operation over the full military
temperature range of – 55°C to 125°C. The
SN74ALS645A
and
SN74AS645
are
characterized for operation from 0°C to 70°C.
OE
•
4
3 2 1 20 19
18
5
17
6
16
7
15
14
8
B1
B2
B3
B4
B5
A8
GND
B8
B7
B6
9 10 11 12 13
FUNCTION TABLE
INPUTS
OPERATION
OE
DIR
L
L
B data to A bus
L
H
A data to B bus
H
X
Isolation
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.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
1
SN54ALS645A, SN54AS645, SN74ALS645A, SN74AS645
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SDAS278 – JANUARY 1995
logic symbol†
OE
DIR
A1
logic diagram (positive logic)
19
1
OE
G3
19
3 EN1 [BA]
3 EN2 [AB]
2
18
1
DIR
1
B1
2
A2
A3
A4
A5
A6
A7
A8
3
17
4
16
5
15
6
14
7
13
8
12
9
11
B2
A1
B3
2
18
B1
B4
B5
B6
B7
To Seven Other Transceivers
B8
† 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, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
Input voltage, VI: All inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
I/O ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 V
Operating free-air temperature range, TA: SN54ALS645A . . . . . . . . . . . . . . . . . . . . . . . . . . . – 55°C to 125°C
SN74ALS645A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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.
recommended operating conditions
SN54ALS645A
VCC
VIH
Supply voltage
VIL
IOH
Low-level input voltage
IOL
Low level output current
Low-level
High-level input voltage
MIN
NOM
MAX
MIN
NOM
MAX
4.5
5
5.5
4.5
5
5.5
2
High-level output current
TA
Operating free-air temperature
§ Applies only to the -1 version and only if VCC is between 4.75 V and 5.25 V
2
SN74ALS645A
POST OFFICE BOX 655303
– 55
• DALLAS, TEXAS 75265
2
UNIT
V
V
0.7
0.8
V
– 12
– 15
mA
12
24
48§
mA
70
°C
125
0
SN54ALS645A, SN54AS645, SN74ALS645A, SN74AS645
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SDAS278 – JANUARY 1995
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
VIK
VOH
SN54ALS645A
TYP†
MAX
TEST CONDITIONS
MIN
VCC = 4.5 V,
VCC = 4.5 V to 5.5 V,
II = – 18 mA
IOH = – 0.4 mA
VCC = 4.5 V
IOH = – 3 mA
IOH = – 12 mA
– 1.5
VCC – 2
2.4
II
VCC = 4.5 V
Control inputs
A or B ports
VCC = 5
5.5
5V
VI = 7 V
VI = 5.5 V
Control inputs
A or B ports§
VCC = 5
5.5
5V
V,
VI = 2
2.7
7V
IIL
Control inputs
A or B ports§
5V
VCC = 5
5.5
V,
4V
VI = 0
0.4
VCC = 5.5 V,
VO = 2.25 V
Outputs high
ICC
3.2
3.2
VCC = 5.5 V
UNIT
V
V
2
0.25
0.4
IOL = 24 mA
IOL = 48 mA‡
IIH
IO¶
– 1.5
VCC – 2
2.4
2
IOH = – 15 mA
IOL = 12 mA
VOL
SN74ALS645A
TYP†
MAX
MIN
– 20
Outputs low
0.25
0.4
0.35
0.5
0.35
0.5
0.1
0.1
0.1
0.1
20
20
20
20
– 0.1
– 0.1
– 0.1
– 0.1
– 112
– 30
– 112
30
48
30
45
36
60
36
55
V
mA
µA
mA
mA
mA
Outputs disabled
38
63
38
58
† All typical values are at 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.
switching characteristics (see Figure 1)
PARAMETER
FROM
(INPUT)
TO
(OUTPUT)
VCC = 4.5 V to 5.5 V,
CL = 50 pF,
R1 = 500 Ω,
R2 = 500 Ω,
TA = MIN to MAX#
SN54ALS645A
tPLH
tPHL
A or B
B or A
tPZH
tPZL
OE
A or B
tPHZ
tPLZ
OE
A or B
UNIT
SN74ALS645A
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
ns
ns
ns
# For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
3
SN54ALS645A, SN54AS645, SN74ALS645A, SN74AS645
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SDAS278 – JANUARY 1995
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)†
Supply voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
Input voltage, VI: All inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V
I/O ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 V
Operating free-air temperature range, TA: SN54AS645 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 55°C to 125°C
SN74AS645 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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.
recommended operating conditions
SN54AS645
SN74AS645
MIN
NOM
MAX
MIN
NOM
MAX
4.5
5
5.5
4.5
5
5.5
UNIT
VCC
VIH
Supply voltage
VIL
IOH
Low-level input voltage
0.8
0.8
V
High-level output current
– 12
– 15
mA
IOL
TA
Low-level output current
48
64
mA
70
°C
High-level input voltage
2
Operating free-air temperature
2
– 55
125
V
V
0
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
VIK
VOH
VOL
II
A or B ports
MIN
VCC = 4.5 V,
VCC = 4.5 V to 5.5 V,
II = – 18 mA
IOH = – 2 mA
VCC = 4.5 V
IOH = – 3 mA
IOH = – 12 mA
VCC = 4
4.5
5V
Control inputs
SN54AS645
TYP‡
MAX
TEST CONDITIONS
VCC = 5
5.5
5V
SN74AS645
TYP‡
MAX
MIN
– 1.2
VCC – 2
2.4
– 1.2
VCC – 2
2.4
3.2
3.2
V
V
2.4
IOH = – 15 mA
IOL = 48 mA
UNIT
2.4
0.3
0.55
IOL = 64 mA
VI = 7 V
0.35
0.55
0.1
0.1
VI = 5.5 V
0.1
0.1
20
20
70
70
– 0.5
– 0.5
– 0.75
– 0.75
IIH
Control inputs
A or B ports§
5V
VCC = 5
5.5
V,
7V
VI = 2
2.7
IIL
Control inputs
A or B ports§
VCC = 5
5.5
5V
V,
VI = 0
0.4
4V
IO¶
VCC = 5.5 V,
VO = 2.25 V
Outputs high
62
97
62
97
ICC
VCC = 5.5 V
Outputs low
95
149
95
149
Outputs disabled
79
123
79
123
– 50
– 150
– 50
– 150
V
mA
µA
mA
mA
mA
‡ All typical values are at VCC = 5 V, TA = 25°C.
§ 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.
4
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SN54ALS645A, SN54AS645, SN74ALS645A, SN74AS645
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SDAS278 – JANUARY 1995
switching characteristics (see Figure 1)
PARAMETER
FROM
(INPUT)
TO
(OUTPUT)
VCC = 4.5 V to 5.5 V,
CL = 50 pF,
R1 = 500 Ω,
R2 = 500 Ω,
TA = MIN to MAX†
SN54AS645
tPLH
tPHL
A or B
B or A
tPZH
tPZL
OE
A or B
tPHZ
tPLZ
OE
A or B
UNIT
SN74AS645
MIN
MAX
MIN
MAX
2
11
2
9.5
2
10.5
2
9
2
12
2
11
2
12
2
10
2
8
2
7
2
13
2
12
ns
ns
ns
† For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
5
SN54ALS645A, SN54AS645, SN74ALS645A, SN74AS645
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SDAS278 – JANUARY 1995
PARAMETER MEASUREMENT INFORMATION
SERIES 54ALS/74ALS AND 54AS/74AS DEVICES
7V
RL = R1 = R2
VCC
S1
RL
R1
Test
Point
From Output
Under Test
CL
(see Note A)
From Output
Under Test
RL
Test
Point
From Output
Under Test
CL
(see Note A)
CL
(see Note A)
LOAD CIRCUIT FOR
BI-STATE
TOTEM-POLE OUTPUTS
LOAD CIRCUIT
FOR OPEN-COLLECTOR OUTPUTS
3.5 V
Timing
Input
Test
Point
LOAD CIRCUIT
FOR 3-STATE OUTPUTS
3.5 V
High-Level
Pulse
1.3 V
R2
1.3 V
1.3 V
0.3 V
0.3 V
Data
Input
tw
th
tsu
3.5 V
1.3 V
3.5 V
Low-Level
Pulse
1.3 V
0.3 V
1.3 V
0.3 V
VOLTAGE WAVEFORMS
SETUP AND HOLD TIMES
VOLTAGE WAVEFORMS
PULSE DURATIONS
3.5 V
Output
Control
(low-level
enabling)
1.3 V
1.3 V
0.3 V
tPZL
Waveform 1
S1 Closed
(see Note B)
tPLZ
[3.5 V
1.3 V
tPHZ
tPZH
Waveform 2
S1 Open
(see Note B)
1.3 V
VOL
0.3 V
VOH
1.3 V
0.3 V
[0 V
3.5 V
1.3 V
Input
1.3 V
0.3 V
tPHL
tPLH
VOH
In-Phase
Output
1.3 V
1.3 V
VOL
tPLH
tPHL
VOH
Out-of-Phase
Output
(see Note C)
1.3 V
1.3 V
VOL
VOLTAGE WAVEFORMS
PROPAGATION DELAY TIMES
VOLTAGE WAVEFORMS
ENABLE AND DISABLE TIMES, 3-STATE OUTPUTS
NOTES: A. CL includes probe and jig capacitance.
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, tr = tf = 2 ns, duty cycle = 50%.
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
PACKAGE OPTION ADDENDUM
www.ti.com
17-Sep-2022
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
Samples
(4/5)
(6)
8403301RA
ACTIVE
CDIP
J
20
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
8403301RA
SNJ54ALS645AJ
Samples
8403301SA
ACTIVE
CFP
W
20
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
8403301SA
SNJ54ALS645AW
Samples
SN54ALS645AJ
ACTIVE
CDIP
J
20
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
SN54ALS645AJ
Samples
SN54AS645J
ACTIVE
CDIP
J
20
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
SN54AS645J
Samples
SN74ALS645A-1DW
ACTIVE
SOIC
DW
20
25
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
ALS645A-1
Samples
SN74ALS645A-1DWR
ACTIVE
SOIC
DW
20
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
ALS645A-1
Samples
SN74ALS645A-1N
ACTIVE
PDIP
N
20
20
RoHS &
Non-Green
NIPDAU
N / A for Pkg Type
0 to 70
SN74ALS645A-1N
Samples
SN74ALS645A-1NSR
ACTIVE
SO
NS
20
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
ALS645A-1
Samples
SN74ALS645ADW
ACTIVE
SOIC
DW
20
25
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
ALS645A
Samples
SN74ALS645ADWR
ACTIVE
SOIC
DW
20
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
ALS645A
Samples
SN74ALS645AN
ACTIVE
PDIP
N
20
20
RoHS &
Non-Green
NIPDAU
N / A for Pkg Type
0 to 70
SN74ALS645AN
Samples
SN74ALS645ANSR
ACTIVE
SO
NS
20
2000
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
0 to 70
ALS645A
Samples
SN74AS645N
ACTIVE
PDIP
N
20
20
RoHS &
Non-Green
NIPDAU
N / A for Pkg Type
0 to 70
SN74AS645N
Samples
SNJ54ALS645AJ
ACTIVE
CDIP
J
20
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
8403301RA
SNJ54ALS645AJ
Samples
SNJ54ALS645AW
ACTIVE
CFP
W
20
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
8403301SA
SNJ54ALS645AW
Samples
SNJ54AS645J
ACTIVE
CDIP
J
20
1
Non-RoHS
& Green
SNPB
N / A for Pkg Type
-55 to 125
SNJ54AS645J
Samples
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
Addendum-Page 1
PACKAGE OPTION ADDENDUM
www.ti.com
17-Sep-2022
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of