SN54HC640, SN74HC640
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SCLS303A – JANUARY 1996 – REVISED MA Y 1997
D
Inverting Logic
D
High-Current 3-State Outputs Can Drive up
to 15 LSTTL Loads
D
Package Options Include Plastic
Small-Outline (DW) and Ceramic Flat (W)
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. These 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
used to disable the device so the buses are
effectively isolated.
The SN54HC640 is characterized for operation
over the full military temperature range of –55°C
to 125°C. The SN74HC640 is characterized for
operation from –40°C to 85°C.
FUNCTION TABLE
INPUTS
OE DIR
L L B data to A bus
L HA data to B bus
H X Isolation
) input can be
SN54HC640 ...J OR W PACKAGE
SN74HC640 . . . DW OR N PACKAGE
SN54HC640 . . . 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
10 11 12 13
9
A8
B8
20
19
18
17
16
15
14
13
12
11
V
CC
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
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
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
Copyright 1997, Texas Instruments Incorporated
1
SN54HC640, SN74HC640
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SCLS303A – JANUARY 1996 – REVISED MA Y 1997
logic symbol
†
This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.
†
OE
DIR
A1
A2
A3
A4
A5
A6
A7
A8
19
1
2
3
4
5
6
7
8
9
G3
3 EN1 [BA]
3 EN2 [AB]
1
2
logic diagram (positive logic)
19
OE
18
17
16
15
14
13
12
11
B1
B2
B3
B4
B5
B6
B7
B8
1
DIR
218
A1
To Seven Other Transceivers
B1
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
SN54HC640, SN74HC640
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SCLS303A – JANUARY 1996 – REVISED MA Y 1997
absolute maximum ratings over operating free-air temperature range
Supply voltage range, V
–0.5 V to 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CC
†
Input clamp current, IIK (VI < 0 or VI > VCC) (see Note 1) ±20 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output clamp current, IOK (VO < 0 or VO > VCC) (see Note 1) ±20 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Continuous output current, IO (VO = 0 to VCC) ±35 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Continuous current through VCC or GND ±70 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Package thermal impedance, θ
(see Note 2): DW package 97°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
JA
N package 67°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range, T
†
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. The package thermal impedance is calculated in accordance with JESD 51, except for through-hole packages, which use a trace
length of zero.
–65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
stg
recommended operating conditions
SN54HC640 SN74HC640
MIN NOM MAX MIN NOM MAX
V
V
V
V
V
t
t
T
Supply voltage 2 5 6 2 5 6 V
CC
VCC = 2 V 1.5 1.5
High-level input voltage
IH
Low-level input voltage
IL
Input voltage 0 V
I
Output voltage 0 V
O
Input transition (rise and fall) time
Operating free-air temperature –55 125 –40 85 °C
A
VCC = 4.5 V
VCC = 6 V 4.2 4.2
VCC = 2 V 0 0.5 0 0.5
VCC = 4.5 V
VCC = 6 V 0 1.8 0 1.8
VCC = 2 V 0 1000 0 1000
VCC = 4.5 V
VCC = 6 V 0 400 0 400
3.15 3.15
0 1.35 0 1.35
CC
CC
0 500 0 500
0 V
0 V
CC
CC
V
V
V
V
ns
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
3