Datasheet

74AHC_AHCT157_2 © NXP B.V. 2007. All rights reserved.
Product data sheet Rev. 02 — 9 November 2007 8 of 16
NXP Semiconductors
74AHC157; 74AHCT157
Quad 2-input multiplexer
[1] Typical values are measured at nominal supply voltage (V
CC
= 3.3 V and V
CC
= 5.0 V).
[2] t
pd
is the same as t
PLH
and t
PHL
.
[3] C
PD
is used to determine the dynamic power dissipation P
D
(µW).
P
D
=C
PD
× V
CC
2
× f
i
+ ∑ (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 Volts.
C
PD
power
dissipation
capacitance
C
L
= 50 pF; f
i
= 1 MHz;
V
I
= GND to V
CC
[3]
4 outputs switching via S - 31 - - - - - pF
1 outputs switching via I - 13 - - - - - pF
For type 74AHCT157
t
pd
propagation
delay
nI0, nI1 to nY; see Figure 7
[2]
V
CC
= 4.5 V to 5.5 V
C
L
= 15 pF - 3.2 6.4 1.0 7.5 1.0 8.0 ns
C
L
= 50 pF - 4.6 8.7 1.0 9.8 1.0 11.0 ns
S to nY; see
Figure 7
V
CC
= 4.5 V to 5.5 V
C
L
= 15 pF - 3.7 8.6 1.0 10.0 1.0 11.0 ns
C
L
= 50 pF - 5.2 10.4 1.0 12.0 1.0 13.0 ns
E to nY; see Figure 8
[2]
V
CC
= 4.5 V to 5.5 V
C
L
= 15 pF - 4.7 8.1 1.0 9.5 1.0 10.5 ns
C
L
= 50 pF - 6.7 10.6 1.0 12.0 1.0 13.5 ns
C
PD
power
dissipation
capacitance
C
L
= 50 pF; f
i
= 1 MHz;
V
I
= GND to V
CC
[3]
4 outputs switching via S - 41 - - - - - pF
1 outputs switching via I - 16 - - - - - pF
Table 7. Dynamic characteristics
…continued
GND = 0 V; For test circuit see Figure 9.
Symbol Parameter Conditions 25 °C −40 °C to +85 °C −40 °C to +125
°C
Unit
Min Typ
[1]
Max Min Max Min Max