SN54ALS640B, SN54AS640, SN74ALS640B, SN74AS640
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SDAS122A – DECEMBER 1983 – REVISED JANUARY 1995
4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
†
Supply voltage, V
CC
7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage, V
I
: All inputs 7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I/O ports 5.5 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating free-air temperature range, T
A
: SN54AS640 –55°C to 125°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SN74AS640 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
SN54AS640 SN74AS640
MIN NOM MAX MIN NOM MAX
V
CC
Supply voltage 4.5 5 5.5 4.5 5 5.5 V
V
IH
High-level input voltage 2 2 V
V
IL
Low-level input voltage 0.8 0.8 V
I
OH
High-level output current –12 –15 mA
I
OL
Low-level output current 48 64 mA
T
A
Operating free-air temperature –55 125 0 70 °C
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
SN54AS640 SN74AS640
MIN TYP
‡
MAX MIN TYP
‡
MAX
V
IK
V
CC
= 4.5 V, I
I
= –18 mA –1.2 –1.2 V
V
CC
= 4.5 V, I
OH
= –2 mA V
CC
–2
V
CC
= 4.5 V to 5.5 V, I
OH
= –2 mA V
CC
–2
V
OH
I
OH
= –3 mA 2.4 3.2 2.4 3.2
V
V
CC
= 4.5 V
I
OH
= –12 mA 2.4
I
OH
= –15 mA 2.4
I
OL
= 48 mA 0.3 0.55
OL
CC
=
.
I
OL
= 64 mA 0.35 0.55
Control inputs
V
I
= 7 V 0.1 0.1
I
A or B ports
CC
=
.
V
I
= 5.5 V 0.1 0.1
Control inputs
20 20
IH
A or B ports
§
CC
=
.
,
I
=
.
70 70
µ
Control inputs
–0.5 –0.5
IL
A or B ports
§
CC
=
.
,
I
=
.
–0.75 –0.75
I
O
¶
V
CC
= 5.5 V, V
O
= 2.25 V –50 –150 –50 –150 mA
Outputs high 37 58 37 58
I
CC
V
CC
= 5.5 V
Outputs low 78 123 78 123
mA
Outputs disabled 51 80 51 80
‡
All typical values are at V
CC
= 5 V, T
A
= 25°C.
§
For I/O ports, the parameters I
IH
and I
IL
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
OS
.
