Datasheet

74HC_HCT244 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
Product data sheet Rev. 4 — 24 September 2012 8 of 18
NXP Semiconductors
74HC244; 74HCT244
Octal buffer/line driver; 3-state
11. Waveforms
Measurement points are given in Table 8.
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
001aae013
t
PLH
t
PHL
V
M
V
M
V
M
V
M
nYn output
nAn input
V
I
GND
V
OH
V
OL
t
TLH
t
THL
90 %
10 %
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. 3-state enable and disable times
001aae014
t
PLZ
t
PHZ
outputs
disabled
outputs
enabled
V
Y
V
X
outputs
enabled
nYn output
LOW-to-OFF
OFF-to-LOW
nYn output
HIGH-to-OFF
OFF-to-HIGH
nOE input
V
I
V
OL
V
OH
V
CC
V
M
GND
GND
t
PZL
t
PZH
V
M
V
M
Table 8. Measurement points
Type Input Output
V
M
V
M
V
X
V
Y
74HC244 0.5  V
CC
0.5  V
CC
0.1  V
CC
0.9  V
CC
74HCT244 1.3 V 1.3 V 0.1  V
CC
0.9  V
CC