MAX1480A_05 Datasheet, PDF (17/21 Pages) Maxim Integrated Products – Complete, Isolated RS-485/RS-422 Data Interface

Complete, Isolated RS-485/RS-422
Data Interface
AB
RE
R
D
RO DE
DI
TERMINATING RESISTOR
(ONE RESISTOR ON EACH END)
AB
RE
R
D
RO DE DI
B
120Ω
A
100Ω
DI
D
DE
R
RO
RE
V_IN
5V
C1
22µF
C2
0.1µF
74HC86
OR EQUIVALENT
R1
DI
DRIVER INPUT
R2
DE
DRIVER ENABLE
R3
RECEIVER OUTPUT
RO
V_{CC1 1}
V_{CC2 2}
D1 3
D2 4
GND1 ₅
FS 6
SD ₇
V_{CC3 8}
DI ₉
V_{CC4 10}
DE ₁₁
GND2 ₁₂
RO ₁₃
V_CC5
14
MAX1480A/B/C
MAX845
MAX487
MAX1487
TERMINATING RESISTOR
(ONE RESISTOR ON EACH END)
28 AC1 (MAKE NO CONNECTION)
27 AC2 (MAKE NO CONNECTION)
26 ^{ISO VCC1}
25 ^B
24 ^{ISO RO DRV}
23 ^A
22 ^{ISO DI IN}
21 ^{ISO DE IN}
R6
R4
20 ^{ISO COM1}
R5
19 ^{ISO DI DRV}
18 ^{ISO VCC2}
17 ^{ISO DE DRV}
16 ^{ISO COM2}
15 ^{ISO RO LED}
B
120Ω
A
SH
SHIELD
(OPTIONAL)
NOTE: RESISTOR R7 PROTECTS
THE MAX1480A/B/C FROM
TRANSIENT CURRENTS
BETWEEN SHIELD AND
TRANSMISSION LINES.
R7
100Ω
LOGIC GROUND ISOLATION BARRIER
ISOLATED COMMON
Figure 13. Typical Half-Duplex RS-485/RS-422 Network
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