F81438 Datasheet, PDF (8/20 Pages) Feature Integration Technology Inc. – Single 5V RS232/RS422/RS485 Multiprotocol

F81438
TABLE 4: RS-422 FULL DUPLEX: MODE 00
DRIVERS
Inputs
Outputs
TX_EN
TX_IN
TX(A)
TX(B)
1
1
0
1
1
0
1
0
0
x
High-Z
RECEIVERS
Inputs
Outputs
RX(A) - RX(B)
RXOUT
> -50mV
1
　< -200mV
0
Open / Shorted
1
5.2 Mode Description
5.2.1
Pure RS-232 (Mode 01)
The F81438 supports all signals used in RS-232 over an 8 pin RJ-45 as defined in
TIA/EIA-561. For DTE serial port only three drivers are required. F81438 may also
be used to implement a standard serial port over a DB-9 connector (TIA/EIA-574 or
the standard IBM serial port). In that case either DSR or RI signal can be
supported. Both DSR and RI are used mainly for dial-up connections and are
typically not needed on dedicated lines. If both signals are required, add a discrete
transceiver such as F81438.
MODE 01
26
6
1
7
28
17
27
18
19
15
20
16
21
4
22
3
Figure 1:
Pure RS-232 Mode
8
Jan, 2012
V0.11P