Data Sheet

74VHCT244A Octal Buffer/Line Driver with 3-STATE Outputs
©1997 Fairchild Semiconductor Corporation www.fairchildsemi.com
74VHCT244A Rev. 1.3 5
AC Electrical Characteristics
Notes:
7. Parameter guaranteed by design. t
OSLH
= |t
PLH max
– t
PLH min
|; t
OSHL
= |t
PHL max
– t
PHL min
|
8. C
PD
is defined as the value of the internal equivalent capacitance which is calculated from the operating
current consumption without load. Average operating current can be obtained by the equation:
I
CC
(Opr.) = C
PD
• V
CC
• f
IN
+ I
CC
/ 8 (per F/F). The total C
PD
when n pcs. of the Octal D Flip-Flop operates
can be calculated by the equation: C
PD
(total) = 20 + 12n
Symbol Parameter V
CC
(V) Conditions
T
A
= 25°C
T
A
= –40°C
to +85°C
UnitsMin. Typ. Max. Min. Max.
t
PLH
, t
PHL
Propagation Delay
Time
5.0 ± 0.5 C
L
= 15pF 5.4 7.4 1.0 8.5 ns
C
L
= 50pF 5.9 8.4 1.0 9.5
t
PZL
, t
PZH
3-STATE Output
Enable Time
5.0 ± 0.5 R
L
= 1kΩ C
L
= 15pF 7.7 10.4 1.0 12.5 ns
C
L
= 50pF 8.2 11.4 1.0 13.5
t
PLZ
, t
PHZ
3-STATE Output
Disable Time
5.0 ± 0.5 R
L
= 1kΩ C
L
= 50pF 8.8 11.4 1.0 13.0 ns
t
OSLH
, t
OSHL
Output to Output
Skew
5.0 ± 0.5
(7)
1.0 1.0 ns
C
IN
Input Capacitance V
CC
= Open 4 10 10 pF
C
OUT
Output Capacitance V
CC
= 5.0V 9 pF
C
PD
Power Dissipation
Capacitance
(8)
18 pF