SCBS081L − JANUARY 1991 − REVISED APRIL 2005
SN54ABT245A, SN74ABT245B
OCTAL BUS TRANSCEIVERS
WITH 3 STATE OUTPUTS
PARAMETER MEASUREMENT INFORMATION
7V
From Output
Under Test
CL = 50 pF
(see Note A)
500
Ω
S1
Open
GND
500
Ω
TEST
tPLH/tPHL
tPLZ/tPZL
tPHZ/tPZH
S1
Open
7V
Open
LOAD CIRCUIT
3V
Timing Input
tw
3V
Input
1.5 V
1.5 V
0V
VOLTAGE WAVEFORMS
PULSE DURATION
VOLTAGE WAVEFORMS
SETUP AND HOLD TIMES
Data Input
tsu
1.5 V
th
3V
1.5 V
0V
1.5 V
0V
3V
Input
1.5 V
tPLH
Output
tPHL
1.5 V
1.5 V
1.5 V
0V
tPHL
VOH
1.5 V
VOL
tPLH
VOH
Output
1.5 V
VOL
VOLTAGE WAVEFORMS
PROPAGATION DELAY TIMES
INVERTING AND NONINVERTING OUTPUTS
Output
Control
tPZL
Output
Waveform 1
S1 at 7 V
(see Note B)
tPZH
Output
Waveform 2
S1 at Open
(see Note B)
3V
1.5 V
1.5 V
0V
tPLZ
1.5 V
3.5 V
VOL + 0.3 V
VOL
tPHZ
1.5 V
VOH − 0.3 V
VOH
≈0
V
VOLTAGE WAVEFORMS
ENABLE AND DISABLE TIMES
LOW- AND HIGH-LEVEL ENABLING
NOTES: A. CL 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
≤
10 MHz, ZO = 50
Ω,
tr
≤
2.5 ns, tf
≤
2.5 ns.
D. The outputs are measured one at a time, with one transition per measurement.
E. All parameters and waveforms are not applicable to all devices.
Figure 1. Load Circuit and Voltage Waveforms
6
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
TI [ TEXAS INSTRUMENTS ]
