Datasheet

AC ELECTRICAL CHARACTERISTICS (C
L
=50pF,Inputt
r
=t
f
=6ns)
Symbol Parameter
Test Conditions Value
Unit
V
CC
(V)
T
A
=25
o
C
54HC and 74HC
-40 to 85
o
C
74HC
-55 to 125
o
C
54HC
Min. Typ. Max. Min. Max. Min. Max.
t
TLH
t
THL
Output Transition
Time
4.5 8151922ns
t
PLH
t
PHL
Propagation
Delay Time
(A, B - Y)
4.5 16 25 31 38 ns
t
PLH
t
PHL
Propagation
Delay Time
(SELECT - Y)
4.5 19 30 38 45 ns
t
PLH
t
PHL
Propagation
Delay Time
(STROBE - Y)
4.5 17 27 34 41 ns
C
IN
Input Capacitance 5 10 10 10 pF
C
PD
(*) Power Dissipation
Capacitance
HCT157 50 pF
HCT158 60 pF
(*) C
PD
isdefined as the value of the IC’s internal equivalent capacitance which is calculated from the operating current consumption without load.
(Refer to Test Circuit).Average operting current can be obtained by the followingequation. I
CC
(opr) = C
PD
•V
CC
•f
IN
+I
CC
/4 (per channel)
SWITCHING CHARACTERISTICS TEST CIR-
CUIT
TEST CIRCUIT I
CC
(Opr.)
INPUT WAVEFORM IS THE SAME AS THAT IN CASE OF
SWITCHINGCHARACTERISTICS TEST.
M54/M74HCT157 M54/M74HCT158
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