Datasheet

SN54ACT245, SN74ACT245
OCTAL BUS TRANSCEIVERS
WITH 3-STATE OUTPUTS
SCAS452E – SEPTEMBER 1994 – REVISED OCTOBER 2002
4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
switching characteristics over recommended operating free-air temperature range,
V
CC
= 5 V ± 0.5 V (unless otherwise noted) (see Figure 1)
PARAMETER
FROM TO
T
A
= 25°C SN54ACT245 SN74ACT245
UNIT
PARAMETER
(INPUT) (OUTPUT)
MIN TYP MAX MIN MAX MIN MAX
UNIT
t
PLH
AorB
BorA
1 4 7.5 1 9 1.5 8
ns
t
PHL
A
or
B
B
or
A
1 4 8 1 10 1 9
ns
t
PZH
OE
AorB
1 5 10 1 12 1.5 11
ns
t
PZL
OE
A
or
B
1 5.5 10 1 13 1.5 12
ns
t
PHZ
OE
AorB
1 5.5 10 1 12 1 11
ns
t
PLZ
OE
A
or
B
1 5 10 1 12 1.5 11
ns
operating characteristics, V
CC
= 5 V, T
A
= 25°C
PARAMETER TEST CONDITIONS TYP UNIT
C
pd
Power dissipation capacitance C
L
= 50 pF, f = 1 MHz 45 pF
PARAMETER MEASUREMENT INFORMATION
LOAD CIRCUIT
t
PLH
t
PHL
3 V
0 V
50% V
CC
50% V
CC
V
OH
V
OL
Input
Output
VOLTAGE WAVEFORMS
From Output
Under Test
C
L
= 50 pF
(see Note A)
S1
2 × V
CC
500 Ω
500 Ω
Open
t
PLH
/t
PHL
t
PLZ
/t
PZL
t
PHZ
/t
PZH
Open
2 × V
CC
Open
TEST S1
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)
V
OL
V
OH
t
PZL
t
PZH
t
PLZ
t
PHZ
≈V
CC
0 V
50% V
CC
V
OL
+ 0.3 V
50% V
CC
≈0 V
VOLTAGE WAVEFORMS
V
OH
– 0.3 V
3 V
1.5 V 1.5 V
1.5 V 1.5 V
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