SN54HC244, SN74HC244
OCTAL BUFFERS AND LINE DRIVERS
WITH 3-STATE OUTPUTS
SCLS130D – DECEMBER 1982 – REVISED AUGUST 2003
PARAMETER MEASUREMENT INFORMATION
V
CC
PARAMETER
R
C
L
S1
S2
L
50 pF
or
150 pF
t
S1
S2
Open
Closed
Closed
Open
PZH
Test
Point
t
t
1 kΩ
1 kΩ
en
R
L
t
From Output
Under Test
PZL
t
t
Open
Closed
Open
PHZ
PLZ
50 pF
C
dis
L
Closed
(see Note A)
50 pF
or
150 pF
t
or t
––
Open
Open
pd
t
LOAD CIRCUIT
V
CC
Input
50%
50%
0 V
t
t
PLH
PHL
90%
V
V
OH
In-Phase
Output
90%
50%
10%
50%
10%
OL
t
Output
Control
(Low-Level
Enabling)
t
r
f
f
V
CC
t
t
PLH
PHL
90%
50%
50%
V
V
OH
90%
t
0 V
Out-of-Phase
Output
50%
10%
50%
10%
t
t
PLZ
PZL
OL
t
≈V
CC
≈V
CC
r
Output
Waveform 1
(See Note B)
50%
VOLTAGE WAVEFORMS
PROPAGATION DELAY AND OUTPUT TRANSITION TIMES
10%
V
OL
OH
t
t
PZH
PHZ
V
CC
V
Output
Waveform 2
(See Note B)
90%
t
90%
90%
Input
50%
10%
50%
10%
50%
0 V
≈0 V
t
r
f
VOLTAGE WAVEFORM
INPUT RISE AND FALL TIMES
VOLTAGE WAVEFORMS
ENABLE AND DISABLE TIMES FOR 3-STATE OUTPUTS
NOTES: A.
C includes probe and test-fixture capacitance.
L
B. Waveform 1 is for an output with internal conditions such that the output is low except when disabled by the output control.
Waveform 2 is for an output with internal conditions such that the output is high except when disabled by the output control.
C. Phase relationships between waveforms were chosen arbitrarily. All input pulses are supplied by generators having the following
characteristics: PRR ≤ 1 MHz, Z = 50 Ω, t = 6 ns, t = 6 ns.
O
r
f
D. The outputs are measured one at a time with one input transition per measurement.
E.
F.
G.
t
t
t
and t
and t
and t
are the same as t
are the same as t
are the same as t
.
dis
en
.
pd
PLZ
PZL
PLH
PHZ
PZH
PHL
.
Figure 1. Load Circuit and Voltage Waveforms
5
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TI [ TEXAS INSTRUMENTS ]
