NXP Semiconductors
74HC257; 74HCT257
Quad 2-input multiplexer; 3-state
11. Waveforms
V
I
input
S, nI0, nI1
GND
t
PHL
V
OH
output
nY
V
OL
t
THL
V
M
VM
10 %
t
TLH
001aad477
V
M
V
M
t
PLH
90 %
Measurement points are given in
V
OL
and V
OH
are typical voltage output levels that occur with the output load.
Fig 6.
Propagation delays input (S, nI0, nI1) to output (nY) and output (nY) transition times
t
r
V
I
OE input
GND
V
CC
10 %
t
PLZ
output
LOW-to-OFF
OFF-to-LOW
V
OL
t
PHZ
output
HIGH-to-OFF
OFF-to-HIGH
GND
outputs
enabled
outputs
disabled
V
OH
90 %
90 %
V
M
t
f
t
PZL
V
M
10 %
t
PZH
V
M
outputs
enabled
001aac479
Measurement points are given in
V
OL
and V
OH
are typical voltage output levels that occur with the output load.
Fig 7.
Table 8.
Type
74HC257
3-state output enable and disable times
Measurement points
Input
V
M
0.5V
CC
1.3 V
Output
V
M
0.5V
CC
1.3 V
74HCT257
74HC_HCT257_5
© NXP B.V. 2010. All rights reserved.
Product data sheet
Rev. 05 — 13 January 2010
9 of 17
PHILIPS [ NXP SEMICONDUCTORS ]
