SN54ALS244C, SN54AS244A, SN74ALS244C, SN74AS244A
OCTAL BUFFERS AND LINE DRIVERS
WITH 3-STATE OUTPUTS
SDAS142C – JULY 1987 – REVISED AUGUST 1995
PARAMETER MEASUREMENT INFORMATION
SERIES 54ALS/74ALS AND 54AS/74AS DEVICES
7 V
R
= R1 = R2
V
CC
L
S1
R1
R
L
Test
Point
From Output
Under Test
From Output
Under Test
Test
Point
Test
Point
From Output
Under Test
C
C
L
R
L
R2
L
C
L
(see Note A)
(see Note A)
(see Note A)
LOAD CIRCUIT FOR
BI-STATE
TOTEM-POLE OUTPUTS
LOAD CIRCUIT
FOR OPEN-COLLECTOR OUTPUTS
LOAD CIRCUIT
FOR 3-STATE OUTPUTS
3.5 V
3.5 V
Timing
Input
High-Level
1.3 V
1.3 V
1.3 V
Pulse
0.3 V
0.3 V
t
h
t
w
t
su
3.5 V
3.5 V
0.3 V
Data
Input
Low-Level
1.3 V
1.3 V
1.3 V
1.3 V
Pulse
0.3 V
VOLTAGE WAVEFORMS
SETUP AND HOLD TIMES
VOLTAGE WAVEFORMS
PULSE DURATIONS
3.5 V
0.3 V
Output
Control
(low-level
enabling)
1.3 V
1.3 V
3.5 V
t
PZL
Input
1.3 V
1.3 V
t
PLZ
0.3 V
PHL
3.5 V
t
Waveform 1
S1 Closed
(see Note B)
t
PLH
1.3 V
V
OH
In-Phase
Output
1.3 V
1.3 V
1.3 V
V
OL
0.3 V
V
OL
t
PHZ
t
PLH
t
PZH
t
PHL
V
OH
V
Waveform 2
S1 Open
(see Note B)
OH
OL
Out-of-Phase
Output
(see Note C)
1.3 V
1.3 V
0.3 V
V
0 V
VOLTAGE WAVEFORMS
PROPAGATION DELAY TIMES
VOLTAGE WAVEFORMS
ENABLE AND DISABLE TIMES, 3-STATE OUTPUTS
NOTES: A.
C includes probe and jig 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. When measuring propagation delay items of 3-state outputs, switch S1 is open.
D. All input pulses have the following characteristics: PRR ≤ 1 MHz, t = t = 2 ns, duty cycle = 50%.
r
f
E. The outputs are measured one at a time with one transition per measurement.
Figure 1. Load Circuits and Voltage Waveforms
6
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