SP336E

23

REV. 1.0.0

3.3V - 5V PROGRAMMABLE RS-232/RS-485/RS-422 SERIAL TRANSCEIVER

2.0 SUGGESTED APPLICATION DIAGRAMS

The SP336E supports all signals used in RS-232 over an 8 pin modular jack (RJ-45) as defined in TIA/EIA-

561. For DTE serial port only three drivers are required. Driver_1 is not used in this configuration and its driver

input should be tied to high or low.

SP336E 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 SP3220E.

An alternative implementation would be to use the SP336E to emulate the functionality of two dual-channel

RS-232 transceivers (2 x SP232’s or equivalent).

Loop-Back

Changing from RS-232 mode (MODE 001) to loop-back mode (MODE 000) duplicates the function of an

external loop-back plug. Loop-back can be used to test serial port functionality or to diagnose faults.