74HC_HCT3G14 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2013. All rights reserved.
Product data sheet Rev. 5 — 9 December 2013 12 of 21
NXP Semiconductors 74HC3G14; 74HCT3G14
Triple inverting Schmitt trigger
14. Application information
The slow input rise and fall times cause additional power dissipation, which can be
calculated using the following formula:
P
add
=f
i
(t
r
I
CC(AV)
+t
f
I
CC(AV)
) V
CC
where:
P
add
= additional power dissipation (W);
f
i
= input frequency (MHz);
t
r
= input rise time (ns); 10 % to 90 %;
t
f
= input fall time (ns); 90 % to 10 %;
I
CC(AV)
= average additional supply current (A).
I
CC(AV)
differs with positive or negative input transitions, as shown in Figure 12 and
Figure 13
.
An example of a relaxation circuit using the 74HC3G14/74HCT3G14 is shown
in Figure 14
.
linear change of V
I
between 0.1V
CC
to 0.9V
CC
.
Fig 12. I
CC(AV)
as a function of V
CC
for 74HC3G14
mna036
0 2.0 4.0 6.0
V
CC
(V)
200
150
50
0
100
ΔI
CC(AV)
(μA)
positive-going
edge
negative-going
edge
