SN74LV244AT
OCTAL BUFFER/DRIVER
WITH 3-STATE OUTPUTS
SCES572C – JUNE 2004 – REVISED AUGUST 2005
www.ti.com
PARAMETER MEASUREMENT INFORMATION
V
CC
From Output
Under Test
C
L
(see Note A)
Test
Point
From Output
Under Test
C
L
(see Note A)
R
L
= 1 kΩ
S1
Open
GND
TEST
t
PLH
/t
PHL
t
PLZ
/t
PZL
t
PHZ
/t
PZH
Open Drain
S1
Open
V
CC
GND
V
CC
LOAD CIRCUIT FOR
TOTEM-POLE OUTPUTS
LOAD CIRCUIT FOR
3-STATE AND OPEN-DRAIN OUTPUTS
3V
Timing Input
t
w
3V
t
su
Data Input
0V
1.5 V
1.5 V
0V
t
h
3V
1.5 V
0V
VOLTAGE WAVEFORMS
SETUP AND HOLD TIMES
3V
3V
1.5 V
t
PZL
50% V
CC
t
PZH
V
OH
50% V
CC
50% V
CC
V
OL
Output
Waveform 2
S1 at GND
(see Note B)
50% V
CC
1.5 V
0V
t
PLZ
≈V
CC
V
OL
+ 0.3 V
t
PHZ
V
OH
− 0.3 V
V
OH
≈0
V
V
OL
Input
1.5 V
1.5 V
VOLTAGE WAVEFORMS
PULSE DURATION
Input
t
PLH
In-Phase
Output
t
PHL
Out-of-Phase
Output
1.5 V
1.5 V
0V
t
PHL
50% V
CC
V
OH
50% V
CC
V
OL
t
PLH
Output
Control
Output
Waveform 1
S1 at V
CC
(see Note B)
VOLTAGE WAVEFORMS
PROPAGATION DELAY TIMES
INVERTING AND NONINVERTING OUTPUTS
VOLTAGE WAVEFORMS
ENABLE AND DISABLE TIMES
LOW- AND HIGH-LEVEL ENABLING
NOTES: A. C
L
includes probe and jig capacitance.
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. All input pulses are supplied by generators having the following characteristics: PRR
≤
1 MHz, Z
O
= 50
Ω,
t
r
≤
3 ns, t
f
≤
3 ns.
D. The outputs are measured one at a time, with one input transition per measurement.
E. t
PLZ
and t
PHZ
are the same as t
dis
.
F. t
PZL
and t
PZH
are the same as t
en
.
G. t
PHL
and t
PLH
are the same as t
pd
.
H. All parameters and waveforms are not applicable to all devices.
Figure 1. Load Circuits and Voltage Waveforms
6
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