74LV138_3 © NXP B.V. 2007. All rights reserved.
Product data sheet Rev. 03 — 15 November 2007 7 of 17
NXP Semiconductors
74LV138
3-to-8 line decoder/demultiplexer; inverting
10. Dynamic characteristics
[1] All typical values are measured at T
amb
=25°C.
[2] t
pd
is the same as t
PLH
and t
PHL
.
[3] Typical values are measured at nominal supply voltage (V
CC
= 3.3 V).
[4] C
PD
is used to determine the dynamic power dissipation (P
D
in µW).
P
D
=C
PD
× V
CC
2
× f
i
× N+Σ(C
L
× V
CC
2
× f
o
) where:
f
i
= input frequency in MHz, f
o
= output frequency in MHz
C
L
= output load capacitance in pF
V
CC
= supply voltage in V
N = number of inputs switching
Σ(C
L
× V
CC
2
× f
o
) = sum of the outputs.
Table 7. Dynamic characteristics
GND = 0 V; For test circuit see Figure 8.
Symbol Parameter Conditions −40 °C to +85 °C −40 °C to +125 °C Unit
Min Typ
[1]
Max Min Max
t
pd
propagation delay An to Yn; see Figure 6
[2]
V
CC
= 1.2 V - 75 - - - ns
V
CC
= 2.0 V - 26 44 - 55 ns
V
CC
= 2.7 V - 19 31 - 39 ns
V
CC
= 3.0 V to 3.6 V; C
L
=15pF
[3]
-12- - -ns
V
CC
= 3.0 V to 3.6 V
[3]
- 15 26 - 32 ns
V
CC
= 4.5 V to 5.5 V - - 17 - 22 ns
E3,
En to Yn; see Figure 6 and
Figure 7
V
CC
= 1.2 V - 75 - - - ns
V
CC
= 2.0 V - 26 43 - 53 ns
V
CC
= 2.7 V - 19 30 - 38 ns
V
CC
= 3.0 V to 3.6 V; C
L
=15pF
[3]
-14- - -ns
V
CC
= 3.0 V to 3.6 V
[3]
- 15 25 - 31 ns
V
CC
= 4.5 V to 5.5 V - - 19 - 24 ns
C
PD
power dissipation
capacitance
C
L
= 50 pF; f
i
= 1 MHz;
V
I
= GND to V
CC
[4]
-45- - -pF
