NXP Semiconductors
74HC138; 74HCT138
3-to-8 line decoder/demultiplexer; inverting
Table 7.
Dynamic characteristics
…continued
Voltages are referenced to GND (ground = 0 V); C
L
= 50 pF unless otherwise specified; for test circuit see
Figure 8.
Symbol Parameter
Conditions
T
amb
= 25
°C
Min
For type 74HCT138
t
pd
propagation
delay
An to Yn; see
V
CC
= 4.5 V
V
CC
= 5 V; C
L
= 15 pF
E3 to Yn; see
V
CC
= 4.5 V
V
CC
= 5 V; C
L
= 15 pF
En to Yn; see
V
CC
= 4.5 V
V
CC
= 5 V; C
L
= 15 pF
t
t
transition
time
power
dissipation
capacitance
Yn; see
and
V
CC
= 4.5 V
C
PD
C
L
= 50 pF; f = 1 MHz;
V
I
= GND to V
CC
T
amb
=
−40 °C
to +85
°C
Min
Max
T
amb
=
−40 °C
to +125
°C
Min
Max
Unit
Typ
Max
-
-
-
-
-
-
20
17
18
19
19
19
35
-
40
-
40
-
-
-
-
-
-
-
44
-
50
-
50
-
-
-
-
-
-
-
53
-
60
-
60
-
ns
ns
ns
ns
ns
ns
-
-
7
67
15
-
-
-
19
-
-
-
22
-
ns
pF
[1]
[2]
[3]
t
pd
is the same as t
PLH
and t
PHL
.
t
t
is the same as t
THL
and t
TLH
.
C
PD
is used to determine the dynamic power dissipation (P
D
in
μW).
P
D
= C
PD
×
V
CC2
×
f
i
×
N +
(C
L
×
V
CC2
×
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;
(C
L
×
V
CC2
×
f
o
) = sum of outputs.
74HC_HCT138
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2012. All rights reserved.
Product data sheet
Rev. 4 — 27 June 2012
8 of 19
PHILIPS [ NXP SEMICONDUCTORS ]
