Data Sheet

74VHC157 Quad 2-Input Multiplexer
©1992 Fairchild Semiconductor Corporation www.fairchildsemi.com
74VHC157 Rev. 1.2 6
AC Electrical Characteristics
Note:
3. 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
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,
I
n
to Z
n
3.3 ± 0.3 C
L
= 15pF 6.2 9.7 1.0 11.5 ns
C
L
= 50pF 8.7 13.2 1.0 15.0
5.0 ± 0.5 C
L
= 15pF 4.1 6.4 1.0 7.5 ns
C
L
= 50pF 5.6 8.4 1.0 9.5
t
PLH
, t
PHL
Propagation Delay,
S to Z
n
3.3 ± 0.3 C
L
= 15pF 8.4 13.2 1.0 15.5 ns
C
L
= 50pF 10.9 16.7 1.0 19.0
5.0 ± 0.5 C
L
= 15pF 5.3 8.1 1.0 9.5 ns
C
L
= 50pF 6.8 10.1 1.0 11.5
t
PLH
, t
PHL
Propagation Delay,
E
to Z
n
3.3 ± 0.3 C
L
= 15pF 8.7 13.6 1.0 16.0 ns
C
L
= 50pF 11.2 17.1 1.0 19.5
5.0 ± 0.5 C
L
= 15pF 5.6 8.6 1.0 10.0 ns
C
L
= 50pF 7.1 10.6 1.0 12.0
C
IN
Input Capacitance V
CC
= Open 4 10 10 pF
C
PD
Power Dissipation
Capacitance
(3)
20 pF