Datasheet

SN75177B, SN75178B
DIFFERENTIAL BUS REPEATERS
SLLS002C – D2606, JULY 1985 – REVISED FEBRUARY 1993
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
2–6
PARAMETER MEASUREMENT INFORMATION
V
OC
2
R
L
2
R
L
V
OD2
V
OL
V
OH
–I
OH
+I
OL
V
ID
Figure 1. Driver V
OD
and V
OC
Figure 2. Receiver V
OH
and V
OL
VOLTAGE WAVEFORMS
50%
t
tD
t
dD
1.5 V
10%
t
tD
≈ 2.5 V
≈ – 2.5 V
90%
50%
Output
t
dD
0 V
3 V
1.5 V
Input
TEST CIRCUIT
Output
(see Note B)
C
L
= 50 pF
R
L
= 54 Ω
50 Ω
Generator
(see Note A)
Figure 3. Driver Differential-Output Test Circuit and Voltage Waveforms
VOLTAGE WAVEFORMS
t
PHZ
1.5 V
2.3 V
0.5 V
0 V
3 V
t
PZH
Output
Input
1.5 V
S1
0 V or 3 V
Output
(see Note B)
C
L
= 50 pF
TEST CIRCUIT
50 Ω
V
OH
V
off
≈ 0
V
(SN75178B)
(SN75177B)
SN75178B
Enable is
Active Low
R
L
= 110 Ω
Generator
(see Note A)
Figure 4. Driver Enable and Disable Times
VOLTAGE WAVEFORMS
5 V
V
OL
0.5 V
t
PZL
3 V
0 V
t
PLZ
1.5 V
2.3 V
1.5 V
Output
Input
TEST CIRCUIT
Output
R
L
= 110 Ω
5 V
S1
(see Note B)
C
L
= 50 pF
50 Ω
3 V or 0 V
(SN75178B)
(SN75177B)
SN75178B
Enable is
Active Low
Generator
(see Note A)
Figure 5. Driver Enable and Disable Times
NOTES: A. The input pulse is supplied by a generator having the following characteristics: PRR ≤ 1 MHz, 50% duty cycle, t
r
≤ 6 ns, t
f
≤ 6 ns,
Z
O
= 50 Ω.
B. C
L
includes probe and jig capacitance.