5962-87552012A Datasheet, PDF (5/22 Pages) Texas Instruments – OCTAL BUFFERS/DRIVERS WITH 3-STATE OUTPUTS

SN54AC244, SN74AC244
OCTAL BUFFERS/DRIVERS
WITH 3-STATE OUTPUTS
SCAS514E − JUNE 1995 − REVISED OCTOBER 2003
switching characteristics over recommended operating free-air temperature range,
V_CC = 5 V ± 0.5 V (unless otherwise noted) (see Figure 1)
PARAMETER
FROM
(INPUT)
TO
(OUTPUT)
T_A = 25°C
SN54AC244 SN74AC244
UNIT
MIN TYP MAX MIN MAX MIN MAX
t_PLH
A
t_PHL
t_PZH
OE
t_PZL
t_PHZ
OE
t_PLZ
1.5
5
7
1 9.5
1 7.5
Y
ns
1.5
5
7
1
9
1 7.5
1.5
5
7
1
9 1.5
8
Y
ns
1.5 5.5
8
1 10.5 1.5 8.5
2.5 6.5
9
1 10.5
1 9.5
Y
ns
2 6.5
9
1
11
2 9.5
operating characteristics, V_CC = 5 V, T_A = 25°C
PARAMETER
C_pd
Power dissipation capacitance per buffer/driver
TEST CONDITIONS
C_L = 50 pF, f = 1 MHz
TYP UNIT
45 pF
From Output
Under Test
C_L = 50 pF
(see Note A)
PARAMETER MEASUREMENT INFORMATION
500 Ω
500 Ω
2 × V_CC
S1
Open
TEST
t_PLH/t_PHL
t_PLZ/t_PZL
t_PHZ/t_PZH
S1
Open
2 × V_CC
Open
Input
t_PLH
Output
LOAD CIRCUIT
50% V_CC
50% V_CC
50% V_CC
V_CC
0V
t_PHL
V_OH
50% V_CC
V_OL
Output
Control
(low-level
enabling)
Output
Waveform 1
S1 at 2 × V_CC
(see Note B)
Output
Waveform 2
S1 at Open
(see Note B)
t_PZL
t_PZH
50% V_CC
50% V_CC
V_CC
0V
t_PLZ
50% V_CC
t_PHZ
≈V_CC
V_OL + 0.3 V _VOL
50% V_CC
V_OH − 0.3 V ^VOH
≈0 V
VOLTAGE WAVEFORMS
VOLTAGE WAVEFORMS
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 ≤ 2.5 ns, t_f ≤ 2.5 ns.
D. The outputs are measured one at a time with one input transition per measurement.
Figure 1. Load Circuit and Voltage Waveforms
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