Datasheet

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

SDAS215A − APRIL 1982 − REVISED DECEMBER 1994
4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
POST OFFICE BOX 1443
• HOUSTON, TEXAS 77251−1443
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)
SN54ALS251 SN74ALS251
MIN MAX MIN MAX
t
PLH
A, B, or C
Y
1 21 5 18
ns
t
PHL
A, B, or C Y
7 34 8 24
ns
t
PLH
A, B, or C
W
5 38 8 24
ns
t
PHL
A, B, or C W
7 26 7 23
ns
t
PLH
Any D
Y
2 15 2 10
ns
t
PHL
Any D
Y
3 23 3 15
ns
t
PLH
Any D
W
3 25 3 15
ns
t
PHL
Any D
W
3 20 3 15
ns
t
PZH
OE
Y
3 21 3 15
ns
t
PZL
OE
Y
3 19 3 15
ns
t
PZH
OE
W
3 21 3 15
ns
t
PZL
OE
W
3 19 3 15
ns
t
PZH
OE
Y
2 12 2 10
ns
t
PZL
OE
Y
1 18 1 10
ns
t
PZH
OE
W
2 12 2 10
ns
t
PZL
OE
W
1 18 1 10
ns
†
For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.