Datasheet

74LV14 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 6 — 12 December 2011 10 of 19
NXP Semiconductors
74LV14
Hex inverting Schmitt trigger
15. Application information
The slow input rise and fall times cause additional power dissipation, this 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
=rise time (ns); 10%to90%;
t
f
= fall time (ns); 90 % to 10 %;
I
CC(AV)
= average additional supply current (A).
Average I
CC(AV)
differs with positive or negative input transitions, as shown in Figure 13.
An example of a relaxation circuit using the 74LV14 is shown in Figure 14
.
(1) Positive-going edge.
(2) Negative-going edge.
Fig 13. Average additional supply current as a function of V
CC
001aah097
V
CC
(V)
1.0 3.02.51.5 2.0
50
25
75
100
ΔI
CC(AV)
(μA)
0
(1)
(2)
Fig 14. Relaxation oscillator
mna035
R
C
f
1
T
---
1
0.8 RC
---------------------
=