74AHC_AHCT3G14 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2013. All rights reserved.
Product data sheet Rev. 8 — 13 May 2013 10 of 19
NXP Semiconductors
74AHC3G14; 74AHCT3G14
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 16
and Figure 17
.
For 74AHC3G14 and 74AHCT3G14 used in relaxation oscillator circuit, see Figure 18
.
Note to the application information:
1. All values given are typical unless otherwise specified.
Linear change of V
I
between 0.1V
CC
to 0.9V
CC
Linear change of V
I
between 0.1V
CC
to 0.9V
CC
Fig 16. Average additional I
CC
for 74AHC3G14 Schmitt
trigger devices
Fig 17. Average additional I
CC
for 74AHCT3G14
Schmitt trigger devices
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
mna058
0462
V
CC
(V)
200
100
50
150
0
ΔI
CC(AV)
(μA)
positive-going
edge
negative-going
edge
