Datasheet

74HC_HCT157 All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2015. All rights reserved.
Product data sheet Rev. 7 — 21 January 2015 8 of 19
NXP Semiconductors
74HC157; 74HCT157
Quad 2-input multiplexer
[1] t
pd
is the same as t
PLH
and t
PHL
.
[2] t
t
is the same as t
THL
and t
TLH
.
[3] C
PD
is used to determine the dynamic power dissipation (P
D
in W).
P
D
=C
PD
 V
CC
2
 f
i
 N+(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;
(C
L
 V
CC
2
 f
o
) = sum of outputs.
11. Waveforms
t
t
transition
time
nY; see Figure 7
[2]
V
CC
= 4.5 V - 7 15 - 19 - 22 ns
C
PD
power
dissipation
capacitance
C
L
=50pF;f=1 MHz;
V
I
= GND to V
CC
 1.5 V
[3]
-70- - - - -pF
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 9.
Symbol Parameter Conditions T
amb
= 25 C T
amb
= 40 C
to +85 C
T
amb
= 40 C
to +125 C
Unit
Min Typ Max Min Max Min Max
Measurement points are given in Table 8.
V
OL
and V
OH
are typical voltage output levels that occur with the output load.
Fig 7. Propagation delay input (nI0, nI1, S) to output (nYn)
DDG
W
3/+
W
3+/
9
0
9
0


9
0
9
0
RXWSXW
Q<
LQSXW
6Q,Q,
9
,
*1'
9
2+
9
2/
W
7/+
W
7+/