NXP Semiconductors
74HC244; 74HCT244
Octal buffer/line driver; 3-state
11. Waveforms
V
I
nAn input
GND
t
PHL
V
OH
nYn output
V
OL
t
THL
90 %
V
M
10 %
t
TLH
001aae013
V
M
V
M
t
PLH
V
M
Measurement points are given in
V
OL
and V
OH
are typical voltage output levels that occur with the output load.
Fig 6.
Input (nAn) to output (nYn) propagation delays and output transition times
V
I
nOE input
GND
t
PLZ
V
CC
nYn output
LOW-to-OFF
OFF-to-LOW
V
OL
t
PHZ
V
OH
nYn output
HIGH-to-OFF
OFF-to-HIGH
GND
outputs
enabled
outputs
disabled
outputs
enabled
001aae014
V
M
t
PZL
V
M
V
X
t
PZH
V
Y
V
M
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
74HC244
3-state enable and disable times
Measurement points
Input
V
M
0.5
V
CC
1.3 V
Output
V
M
0.5
V
CC
1.3 V
V
X
0.1
V
CC
0.1
V
CC
V
Y
0.9
V
CC
0.9
V
CC
74HCT244
74HC_HCT244
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© NXP B.V. 2012. All rights reserved.
Product data sheet
Rev. 4 — 24 September 2012
8 of 18
PHILIPS [ NXP SEMICONDUCTORS ]
