
M
+3.0V to+5.5V, 1μA, RS-232/RS-485/422
Multiprotocol Transceivers
20
______________________________________________________________________________________
Multiprotocol Bus Multiplexer
The
Typical Application Circuit
shows the MAX3161 con-
figured as a multiprotocol bus multiplexer. The MAX3161
separates the RS-232 and RS-485 lines, but shares the
logic pins between modes. This application allows the
μP to monitor a point-to-point RS-232 bus, and a mul-
tidrop RS-485 interface. The MAX3100 UART asynchro-
nously transfers data through the MAX3161 to the
pin-selected RS-232 or RS-485 protocol.
A
B
Z
D
DATA OUT
DATA IN
R
DI
DE485
RE485
RO
Y
120
120
NOTE:
RE485 ON MAX3162 ONLY
MAX3160
MAX3161
MAX3162
Figure 14. RS-485 Line Repeater
MAX3162
R1OUT
RO
RE485
TE485
A
B
Z
Y
V-
R1IN
RE232
TE232
FAST
V+
T1OUT
C2-
C2+
C1-
C1+
V
CC
T1IN
R2OUT
DI
R2IN
GND
23
22
13
5
10
23
19
20
15
16
14
28
25
7
6
18
17
22
12
9
11
24
3
1
C1
100nF
C2
100nF
RCV
TX
RTS
C3
100nF
C4
100nF
2
3.3V
C
100nF
SHDN
Figure 15. Protocol Translator