Datasheet

SN54ALS688, SN74ALS688
8-BIT IDENTITY COMPARATORS
SDAS228A – JUNE 1982 – REVISED JANUARY 1995
4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
recommended operating conditions
SN54ALS688 SN74ALS688
UNIT
MIN NOM MAX MIN NOM MAX
UNIT
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 0.7 0.8 V
I
OH
High-level output current –1 –2.6 mA
I
OL
Low-level output current 12 24 mA
T
A
Operating free-air temperature –55 125 0 70 °C
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
TEST CONDITIONS
SN54ALS688 SN74ALS688
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
=45V
I
OH
= – 1 mA 2.4 3.3
V
V
CC
=
4
.
5
V
I
OH
= – 2.6 mA 2.4 3.3
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
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
I
CC
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, 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
(INPUT)
(OUTPUT)
SN54ALS688 SN74ALS688
MIN MAX MIN MAX
t
PLH
P
PQ
3 16 3 12
ns
t
PHL
P
P
=
Q
5 25 5 20
ns
t
PLH
Q
PQ
3 16 3 12
ns
t
PHL
Q
P
=
Q
5 25 5 20
ns
t
PLH
G
P=Q
3 15 3 12
ns
t
PHL
G
P
=
Q
5 25 5 22
ns
§
For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.