MAX1480A_05 Datasheet, PDF (15/21 Pages) Maxim Integrated Products – Complete, Isolated RS-485/RS-422 Data Interface

Complete, Isolated RS-485/RS-422
Data Interface
____________________________________________________Test Circuits (continued)
OUTPUT
UNDER TEST
500Ω
C_L
ISO V_CC_
S1
S2
Figure 6. Driver Timing Test Load
Switching Waveforms
V_{CC_} - 0.4V
V_{CC_} - 0.4V
2
DI´ 0V
B
A
V_DIFF
V_O
0V
-V_O
V_O
1/2 V_O
10%
t_R
V_{CC_} - 0.4V
2
t_PLH
t_PHL
1/2 V_O
V_DIFF = V (A) - V (B)
90%
90%
10%
t_F
t_{SKEW =} t_PLH - t_PHL 
Figure 7. Driver Propagation Delays and Transition Times
V_{CC_} -0.4V
V_{CC_} - 0.4V
DE´ _0V
2
A, B
V_OL
A, B
0V
V_{CC_} - 0.4V
2
t_ZL
t_LZ
2.3V _{OUTPUT NORMALLY LOW}
OUTPUT NORMALLY HIGH
2.3V
t_ZH
t_HZ
V_OL + 0.5V
V_OH - 0.5V
Figure 8. Driver Enable and Disable Times
2.4V
SD
1.6V
0.8V
A, B
V_OL
A, B
0V
1.6V
t_ZL(SHDN)
t_SHDN
2.3V _{OUTPUT NORMALLY LOW}
OUTPUT NORMALLY HIGH
2.3V
t_ZH(SHDN)
t_SHDN
V_OL + 0.5V
V_OH - 0.5V
Figure 9. Times to/from Shutdown
V_ID
0V
-V_ID
V_A - V_B
RO V_OH
V_OL
INPUT
0V
MAX1490A/B
OUTPUT
t_PHL
1.5V
1.5V
t_PLH
V_OH
RO
V_OL
MAX1480A/B/C
1.5V
OUTPUT
1.5V
t_PHL
t_PLH
t_SKEW = t_{PLH -} t_PHL
Figure 10. Receiver Propagation Delays
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