Datasheet
SDAS124C − APRIL 1982 − REVISED AUGUST 1996
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
SN54ALS257A
SN54ALS258A
SN74ALS257A
SN74ALS258A
UNIT
PARAMETER
TEST CONDITIONS
MIN TYP
†
MAX MIN TYP
†
MAX
UNIT
V
IK
V
CC
= 4.5 V, I
I
= −18 mA −1.5 −1.5 V
V
CC
= 4.5 V to 5.5 V, I
OH
= −0.4 mA V
CC
−2 V
CC
−2
V
OH
V
CC
= 4.5 V
I
OH
= −1 mA 2.4 3.3
V
V
OH
V
CC
= 4.5 V
I
OH
= −2.6 mA 2.4 3.2
V
V
OH
V
CC
= 4.5 V
I
OL
= 12 mA 0.25 0.4 0.25 0.4
V
V
OH
V
CC
= 4.5 V
I
OL
= 24 mA 0.35 0.5
V
I
OZH
V
CC
= 5.5 V, V
O
= 2.7 V 20 20 µA
I
OZL
V
CC
= 5.5 V, V
O
= 0.4 V −20 −20 µA
I
I
V
CC
= 5.5 V, V
I
= 7 V 0.1 0.1 mA
I
IH
V
CC
= 5.5 V, V
I
= 2.7 V 20 20 µA
I
IL
V
CC
= 5.5 V, V
I
= 0.4 V −0.1 −0.1 mA
I
O
‡
V
CC
= 5.5 V, V
O
= 2.25 V −20 −112 −30 −112 mA
SN54ALS257A,
Outputs high 3 8 3 6
SN54ALS257A
,
SN74ALS257A
V
CC
= 5.5 V
Outputs low 8 12 8 12
I
CC
SN74ALS257A
V
CC
= 5.5 V
Outputs disabled 9 14 9 14
mA
I
CC
SN54ALS258A,
Outputs high 2.5 5 2.5 4
mA
SN54ALS258A
,
SN74ALS258A
V
CC
= 5.5 V
Outputs low 7 11 7 11
SN74ALS258A
V
CC
= 5.5 V
Outputs disabled 8 13 8 13
†
All typical values are at V
CC
= 5 V, T
A
= 25°C.
‡
The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, I
OS
.
switching characteristics (see Figure 1)
PARAMETER
FROM
(INPUT)
TO
(OUTPUT)
V
CC
= 4.5 V to 5.5 V,
C
L
= 50 pF,
R1 = 500 Ω,
R2 = 500 Ω,
T
A
= MIN to MAX
§
UNIT
(INPUT)
(OUTPUT)
SN54ALS257A SN74ALS257A
MIN MAX MIN MAX
t
PLH
A or B
Any Y
2 12 2 10
ns
t
PHL
A or B Any Y
2 14 2 12
ns
t
PLH
A/B
Any Y
4 21 6 18
ns
t
PHL
A/B
Any Y
6 25 6 22
ns
t
PZH
OE
Any Y
3 20 4 16
ns
t
PZL
OE
Any Y
4 22 5 18
ns
t
PHZ
OE
Any Y
2 12 2 10
ns
t
PLZ
OE
Any Y
2 35 4 15
ns
§
For conditions shown MIN or MAX, use the appropriate value specified under recommended operating conditions.