Datasheet

SN54ALS645A, SN54AS645, SN74ALS645A, SN74AS645
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SDAS278 – JANUARY 1995
3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
TEST CONDITIONS
SN54ALS645A SN74ALS645A
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
I
OH
= –3 mA 2.4 3.2 2.4 3.2
V
V
OH
V
CC
= 4.5 V
I
OH
= –12 mA 2
V
I
OH
= –15 mA 2
I
OL
= 12 mA 0.25 0.4 0.25 0.4
V
OL
V
CC
= 4.5 V
I
OL
= 24 mA 0.35 0.5
V
I
OL
= 48 mA
‡
0.35 0.5
I
I
Control inputs
V
CC
=55V
V
I
= 7 V 0.1 0.1
mA
I
I
A or B ports
V
CC
=
5
.
5
V
V
I
= 5.5 V 0.1 0.1
mA
I
IH
Control inputs
V
CC
=55V
V
I
=27V
20 20
µA
I
IH
A or B ports
§
V
CC
=
5
.
5
V
,
V
I
=
2
.
7
V
20 20
µ
A
I
IL
Control inputs
V
CC
=55V
V
I
=04V
–0.1 –0.1
mA
I
IL
A or B ports
§
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
Outputs high 30 48 30 45
I
CC
V
CC
= 5.5 V
Outputs low 36 60 36 55
mA
Outputs disabled 38 63 38 58
†
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.
¶
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
SN54ALS645A SN74ALS645A
MIN MAX MIN MAX
t
PLH
AorB
BorA
1 19 3 10
ns
t
PHL
A
or
B
B
or
A
1 14 3 10
ns
t
PZH
OE
AorB
2 30 5 20
ns
t
PZL
OE
A
or
B
2 29 5 20
ns
t
PHZ
OE
AorB
2 14 2 10
ns
t
PLZ
OE
A
or
B
2 30 4 15
ns
#
For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.