NXP Semiconductors
74HC257; 74HCT257
Quad 2-input multiplexer; 3-state
Table 7.
Dynamic characteristics
…continued
Voltages are referenced to GND (ground = 0 V); For test circuit see
Figure 8.
Symbol Parameter
Conditions
25
°C
Typ
t
t
transition time
see
V
CC
= 2.0 V
V
CC
= 4.5 V
V
CC
= 6.0 V
C
PD
power dissipation
capacitance
propagation delay
per multiplexer;
V
I
= GND to V
CC
nl0 to nY or nl1 to nY;
see
V
CC
= 4.5 V
V
CC
= 5.0 V; C
L
= 15 pF
S to nY; see
V
CC
= 4.5 V
V
CC
= 5.0 V; C
L
= 15 pF
t
en
t
dis
t
t
C
PD
enable time
disable time
transition time
power dissipation
capacitance
t
pd
is the same as t
PHL
, t
PLH
.
t
en
is the same as t
PZH
, t
PZL
.
t
dis
is the same as t
PHZ
, t
PLZ
.
t
t
is the same as t
THL
, 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.
−40 °C
to
+85
°C
Max
75
15
13
−40 °C
to Unit
+125
°C
Max
90
18
15
ns
ns
ns
pF
Max
60
12
10
-
14
5
4
45
74HCT257
t
pd
16
13
20
17
30
-
35
-
30
30
12
-
38
-
44
38
38
15
45
ns
ns
53
45
45
18
ns
ns
ns
ns
ns
pF
OE to nY; V
CC
= 4.5 V;
see
OE to nY; V
CC
= 4.5 V;
see
V
CC
= 4.5 V; see
per multiplexer;
V
I
= GND to V
CC
15
16
5
45
[1]
[2]
[3]
[4]
[5]
74HC_HCT257_5
© NXP B.V. 2010. All rights reserved.
Product data sheet
Rev. 05 — 13 January 2010
8 of 17
PHILIPS [ NXP SEMICONDUCTORS ]
