Datasheet
SCLS304B – JANUARY 1996 – REVISED DECEMBER 2002
3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
NOTE 3: All unused inputs of the device must be held at V
CC
or GND to ensure proper device operation. Refer to the TI application report,
Implications of Slow or Floating CMOS Inputs, literature number SCBA004.
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
TEST CONDITIONS
V
T
A
= 25°C SN54HC645 SN74HC645
UNIT
PARAMETER TEST CONDITIONS V
CC
MIN TYP MAX MIN MAX MIN MAX
UNIT
2 V 1.9 1.998 1.9 1.9
I
OH
= –20 µA
4.5 V 4.4 4.499 4.4 4.4
V
OH
V
I
= V
IH
or V
IL
I
OH
20
µA
6 V 5.9 5.999 5.9 5.9
V
V
OH
V
I
V
IH
or
V
IL
I
OH
= –6 mA 4.5 V 3.98 4.3 3.7 3.84
V
I
OH
= –7.8 mA 6 V 5.48 5.8 5.2 5.34
2 V 0.002 0.1 0.1 0.1
I
OL
= 20 µA
4.5 V 0.001 0.1 0.1 0.1
V
OL
V
I
= V
IH
or V
IL
I
OL
20
µA
6 V 0.001 0.1 0.1 0.1
V
V
OL
V
I
V
IH
or
V
IL
I
OL
= 6 mA 4.5 V 0.17 0.26 0.4 0.33
V
I
OL
= 7.8 mA 6 V 0.15 0.26 0.4 0.33
I
I
DIR or OE V
I
= V
CC
or 0 6 V ±0.1 ±100 ±1000 ±1000 nA
I
OZ
A or B V
O
= V
CC
or 0 6 V ±0.01 ±0.5 ±10 ±5 µA
I
CC
V
I
= V
CC
or 0, I
O
= 0 6 V 8 160 80 µA
C
i
DIR or OE 2 V to 6 V 3 10 10 10 pF
switching characteristics over recommended operating free-air temperature range, C
L
= 50 pF
(unless otherwise noted) (see Figure 1)
PARAMETER
FROM TO
V
T
A
= 25°C SN54HC645 SN74HC645
UNIT
PARAMETER
FROM
(INPUT)
TO
(OUTPUT)
V
CC
MIN TYP MAX MIN MAX MIN MAX
UNIT
2 V 40 105 160 130
t
pd
A or B B or A
4.5 V 15 21 32 26
ns
t
d
A
or
B
B
or
A
6 V 12 18 27 22
ns
2 V 125 230 340 290
t
en
OE A or B
4.5 V 23 46 68 58
ns
t
en
OE
A
or
B
6 V 20 39 58 49
ns
2 V 74 200 300 250
t
dis
OE A or B
4.5 V 25 40 60 50
ns
t
dis
OE
A
or
B
6 V 21 34 51 43
ns
2 V 20 60 90 75
t
t
A or B
4.5 V 8 12 18 15
ns
t
6 V 6 10 15 13