Rainbow Electronics MAX3430 - 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