Datasheet

+3.0V to+5.5V, 1µA, RS-232/RS-485/422
Multiprotocol Transceivers
RS-485/422 Line Length vs. Data Length
The RS-485/422 standard covers line lengths up to
4000 feet. For line lengths greater than 4000 feet, use
the repeater application shown in Figure 14.
RS-232/RS-485 Protocol Translator
Figure 15 shows the MAX3162 configured as an RS-
232/RS-485 protocol translator. The direction of transla-
tion is controlled through the RTS signal (R1IN). The
single-ended RS-232 receiver input signal is translated
to a differential RS-485 transmitter output. Similarly, a
differential RS-485 receiver input signal is translated to
a single-ended RS-232 transmitter output. RS-232 data
received on R2IN is transmitted as an RS-485 signal on
Z and Y. RS-485 signals received on A and B are trans-
mitted as an RS-232 signal on T1OUT.
Multiprotocol Bus
The Typical Operating Circuit shows a standard appli-
cation for the MAX3160. The MAX3160’s output pins
are multiplexed between RS-232 and RS-485 protocols
by a microprocessor (µP). The µP also directs the shut-
down functions, enable lines, and the duplex of the
MAX3160. Data is transmitted to the MAX3100 UART
through an SPI™ port. The UART asynchronously
MAX 3160-2 FIG10
T1OUT
2V/div
SHDN
5V/division
T2OUT
2V/div
GND
40μs/div
Figure 10. MAX3160 RS-232 Transmitter Outputs When Exiting
Shutdown
MAX 3160-2 FIG12
T
OUT
5V/div
R
OUT
T
IN
1μs/div
Figure 12. RS-232 Loopback Test Result at 250kbps, FAST =
Low
MAX 3160-2 FIG13
T
IN
T
OUT
5V/div
R
OUT
200ns/div
Figure 13. RS-232 Loopback Test Result at 1000kbps, FAST =
High
MAX3160
MAX3161
MAX3162
5k
R_ IN
R_ OUT
C2-
C2+
C1-
C1+
V-
V+
V
CC
C4
C3
C1
C2
V
CC
C
BYPASS
SHDN
T_ OUT
T_ IN
GND
V
CC
1000pF
Figure 11. Loopback Test Circuit
SPI is a trademark of Motorola, Inc.
Maxim Integrated
19
MAX3160/MAX3161/MAX3162