Datasheet
SN54ALS520, SN74ALS518, SN74ALS520, SN74ALS521
8-BIT IDENTITY COMPARATORS
SDAS224B – JUNE 1982 – REVISED NOVEMBER 1995
7
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER TEST CONDITIONS
SN54ALS520
SN74ALS520
SN74ALS521
UNIT
MIN TYP
†
MAX MIN TYP
†
MAX
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
=45V
I
OH
= – 1 mA 2.4 3.3
V
V
CC
=
4
.
5
V
I
OH
= – 2.6 mA 2.4 3.2
V
OL
V
CC
=45V
I
OL
= 12 mA 0.25 0.4 0.25 0.4
V
V
OL
V
CC
=
4
.
5
V
I
OL
= 24 mA 0.35 0.5
V
I
I
′ALS520 Q inputs
V
CC
=55V
V
I
= 5.5 V 0.1 0.1
mA
I
I
All other inputs
V
CC
=
5
.
5
V
V
I
= 7 V 0.1 0.1
mA
I
′ALS520 Q inputs
V
CC
=55V
V
I
=27V
–0.2 –0.2 mA
I
IH
All other inputs
V
CC
=
5
.
5
V
,
V
I
=
2
.
7
V
20 20 µA
I
IL
′ALS520 Q inputs
V
CC
=55V
V
I
=04V
–0.6 –0.6
mA
I
IL
All other inputs
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
I
CC
′ALS520
V
CC
=55V
See Note 1
12 19 12 19
mA
I
CC
SN74ALS521
V
CC
=
5
.
5
V
,
See
Note
1
12 19 12 19
mA
†
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
.
NOTE 1: I
CC
is measured with G
grounded, and P and Q at 4.5 V.
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
= 500 Ω
,
T
A
= MIN to MAX
§
UNIT
PARAMETER
(INPUT) (OUTPUT)
SN54ALS520
SN74ALS520
SN74ALS521
UNIT
MIN MAX MIN MAX
t
PLH
PorQ
PQ
3 19 3 12
ns
t
PHL
P
or
Q
P
=
Q
3 25 5 20
ns
t
PLH
G
P=Q
2 18 2 12
ns
t
PHL
G
P
=
Q
5 23 5 22
ns
§
For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.