Test circuits/timing diagrams – Rainbow Electronics MAX3430 User Manual
Page 6
MAX3430
±80V Fault-Protected, Fail-Safe,
1/4-Unit Load, +3.3V RS-485 Transceiver
6
_______________________________________________________________________________________
V
OD
V
OC
2
R
L
2
R
L
A
B
Figure 1. Driver DC Test Load
V
O
3V
R
L
C
L
C
L
DI
DE
A
B
Figure 2. Driver Timing Test Circuit
t
DPLH
t
DPHL
DI
0
V
CC
A
B
1/2 V
O
1/2 V
O
V
OD
= V (A) - V (B)
t
SKEW
= |t
DPLH
- t
DPHL
|
V
CC
/2
t
DR
t
DF
V
O
20%
80%
80%
20%
V
O
Figure 3. Driver Propagation Delays
V
CC
50
Ω
R
L
= 500
Ω
C
L
50pF
GENERATOR
D
0 OR +3V
OUT
S1
V
CC
0
0.25V
V
OL
t
DZL
, t
DZL(SHDN)
V
OM
= (V
OL
+ V
CC
)/2
V
CC
/2
V
CC
OUT
DE
t
DLZ
Figure 4. Driver Enable and Disable Times (t
DZL
, t
DLZ
,
t
DLZ(SHDN)
)
V
CC
0
0
V
OH
0.25V
50
Ω
R
L
= 500
Ω
C
L
50pF
GENERATOR
D
0 OR +3V
t
DZH
, t
DZH(SHDN)
V
OM
= (0 + V
OH
)/2
V
CC
/2
OUT
OUT
S1
DE
t
DHZ
Figure 5. Driver Enable and Disable Times (t
DHZ
, t
DZH
, t
DZH(SHDN)
)
Test Circuits/Timing Diagrams