SP336E
3.3V - 5V PROGRAMMABLE RS-232/RS-485/RS-422 SERIAL TRANSCEIVER
MARCH 2010
REV. 1.0.0
GENERAL DESCRIPTION
The SP336E is a monolithic serial multi-transceiver
device that contains both RS-232 and RS-485/RS-
422 line drivers and receivers. The configuration of
the SP336E can be reconfigured into eight operating
modes including RS-232 only (4TX/4RX), RS-485/
RS-422 only (2TX/2RX) full or half duplex, two RS-
232/RS-485 mixed modes. two shutdown modes and
a diagnostic loop-back mode. Modes may be
selected at any time by changing the logic state of the
three MODE pins. The device can implement a dual-
mode serial port, mixed mode ports or as an interface
signal translator. The Exar charge pumps deliver true
RS-232 driver output voltages from a single power
supply at either 3.3V or 5V. The SP336E requires
only four 0.1μF capacitors for charge pump. A slew
rate control pin configures driver outputs for either
high data rate or slew-controlled data rates. Slew-
controlled outputs minimize problems with reflections
and ringing on long or un-terminated cables. All RS-
485 receivers or transceivers feature high impedance
which allow up to 256 transceivers on a shared bus.
When configured in RS-485/RS-422 mode, each
driver may be individually enabled or put into tri-state,
simplifying use on shared buses or bidirectional
communication. All receivers have advanced failsafe
protection to prevent oscillation when inputs are un-
connected. In RS-232 mode each receiver input has
a 5k ohm pull-down to ground. Differential Receivers
will default to output logic 1 if inputs are floating,
shorted or open but terminated. All driver outputs and
receiver inputs are protected against ESD strikes up
to +/-15,000 volts.
FEATURES
•
3.3V or 5V Single Supply Operation
•
Robust +/-15kV ESD Protection (IEC 61000-4-2 Air
Gap)
•
Software Selectable Mode Selection
•
Up to 4 Drivers, 4 Receivers RS-232/V.28
•
Up to 2 Drivers, 2 Receivers RS-485/RS-422
■
■
Full or Half Duplex Configurations
1/8th Unit Load, up to 256 receivers on bus
•
Mixed RS-232/RS-485 modes
•
Pin Programmable Slew Rate for Reduced EMI
•
RS-485 Advanced Failsafe on Open, Short or
Terminated Lines
•
Diagnostic Loop-Back Function
•
28 Pin SOIC or TSSOP Packaging
TYPICAL APPLICATIONS
•
Factory Automation Equipment
•
Security Networks
•
Industrial/Process Control Networks
•
Point-Of-Sales Equipment
•
Gaming Machines
•
Serial Protocol Translators (ex. RS-232 to RS-485/
RS-422)
•
Embedded Industrial PC’s
•
Building Environmental Control Systems (ex.
HVAC)
•
Cable Repeaters / Port Extenders / Hubs
Exar
Corporation 48720 Kato Road, Fremont CA, 94538
•
(510) 668-7000
•
FAX (510) 668-7017
•
www.exar.com
EXAR [ EXAR CORPORATION ]
