Datasheet
SDAS300 − MARCH 1995
4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
POST OFFICE BOX 1443
• HOUSTON, TEXAS 77251−1443
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
TEST CONDITIONS
SN74ALS641A
SN74ALS642A
UNIT
PARAMETER
TEST CONDITIONS
MIN TYP
†
MAX
UNIT
V
IK
V
CC
= 4.5 V, I
I
= −18 mA −1.5 V
I
OH
V
CC
= 4.5 V, V
OH
= 5.5 V 0.1 mA
I
OL
= 12 mA 0.25 0.4
V
OL
V
CC
= 4.5 V
I
OL
= 24 mA 0.35 0.5
V
V
OL
V
CC
= 4.5 V
I
OL
= 48 mA
‡
0.35 0.5
V
I
I
Control inputs V
CC
= 5.5 V, V
I
= 7 V 0.1 mA
I
IH
Control inputs
V
CC
= 5.5 V,
V
I
= 2.7 V
20
A
I
IH
A or B ports
§
V
CC
= 5.5 V, V
I
= 2.7 V
20
µA
I
IL
Control inputs
V
CC
= 5.5 V,
V
I
= 0.4 V
−0.1
mA
I
IL
A or B ports
§
V
CC
= 5.5 V, V
I
= 0.4 V
−0.1
mA
SN74ALS641A
V
CC
= 5.5 V
Outputs high 25 37
I
CC
SN74ALS641A V
CC
= 5.5 V
Outputs low 33 47
mA
I
CC
SN74ALS642A
V
CC
= 5.5 V
Outputs high 8 15
mA
SN74ALS642A
V
CC
= 5.5 V
Outputs low 18 28
†
All typical values are at V
CC
= 5 V, T
A
= 25°C.
‡
Applies only to the -1 version and only if V
CC
is between 4.75 V and 5.25 V
§
For I/O ports, the parameters I
IH
and I
IL
include the off-state output current.
switching characteristics (see Figure 1)
PARAMETER
FROM
(INPUT)
TO
(OUTPUT)
V
CC
= 4.5 V to 5.5 V,
C
L
= 50 pF,
R
L
= 680 Ω,
T
A
= MIN to MAX
¶
UNIT
PARAMETER
(INPUT)
(OUTPUT)
SN74ALS641A SN74ALS642A
UNIT
MIN MAX MIN MAX
t
PLH
A or B
B or A
5 25 10 30
ns
t
PHL
A or B
B or A
3 18 5 22
ns
t
PLH
OE
A or B
8 30 10 30
ns
t
PHL
OE A or B
8 30 15 38
ns
t
PLH
DIR
A or B
8 32 10 30
ns
t
PHL
DIR
A or B
8 32 15 38
ns
¶
For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.