SN54AC244, SN74AC244
OCTAL BUFFERS/DRIVERS
WITH 3-STATE OUTPUTS
SCAS514E − JUNE 1995 − REVISED OCTOBER 2003
switching characteristics over recommended operating
V
CC
= 5 V
±
0.5 V (unless otherwise noted) (see Figure 1)
PARAMETER
t
PLH
t
PHL
t
PZH
t
PZL
t
PHZ
t
PLZ
FROM
(INPUT)
A
OE
OE
TO
(OUTPUT)
Y
Y
Y
T
A
= 25°C
MIN
1.5
1.5
1.5
1.5
2.5
2
TYP
5
5
5
5.5
6.5
6.5
free-air
temperature
SN74AC244
MIN
1
1
1.5
1.5
1
2
MAX
7.5
7.5
8
8.5
9.5
9.5
range,
UNIT
ns
ns
ns
SN54AC244
MAX
7
7
7
8
9
9
MIN
1
1
1
1
1
1
MAX
9.5
9
9
10.5
10.5
11
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
45
UNIT
pF
PARAMETER MEASUREMENT INFORMATION
2
×
V
CC
From Output
Under Test
C
L
= 50 pF
(see Note A)
500
Ω
S1
Open
TEST
t
PLH
/t
PHL
t
PLZ
/t
PZL
t
PHZ
/t
PZH
S1
Open
2
×
V
CC
Open
500
Ω
LOAD CIRCUIT
Output
Control
(low-level
enabling)
V
CC
t
PZL
Output
Waveform 1
S1 at 2
×
V
CC
(see Note B)
t
PZH
V
OH
Output
Waveform 2
S1 at Open
(see Note B)
V
CC
50% V
CC
t
PLZ
≈V
CC
50% V
CC
t
PHZ
50% V
CC
V
OH
− 0.3 V
V
OH
≈0
V
VOLTAGE WAVEFORMS
V
OL
+ 0.3 V
V
OL
50% V
CC
0V
Input
t
PLH
50% V
CC
50% V
CC
0V
t
PHL
Output
50% V
CC
50% V
CC
V
OL
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
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
5
TI [ TEXAS INSTRUMENTS ]
