SP335E
RS-232/RS-485/RS-422 TRANSCEIVER WITH INTERNAL TERMINATION
August 2017
Rev. 1.0.2
FEATURES
GENERAL DESCRIPTION
Pin-Selectable Cable Termination
The SP335 is an advanced multiprotocol transceiver
supporting RS-232, RS-485, and RS-422 serial
standards. Integrated cable termination and multiple
configuration modes allow all three protocols to be
No External Resistors Required for RS-485/422
Termination or Biasing
Robust ESD Protection:
used interchangeably over
a
single cable or
connector with no additional switching components.
Full operation requires only four external charge
pump capacitors.
■ ±15kV IEC 61000-4-2 Air Gap Discharge
■ ± 8kV IEC 61000-4-2 Contact Discharge
■ ±15kV Human Body Model (HBM)
The RS-485/RS-232 mode pin selects RS-485 mode
when high, and RS-232 mode when low. In RS-485
mode, the TERM pin enables the differential 120
termination, and the HALF/FULL pin configures the
transceiver as either half or full duplex.
20Mbps RS-485 and 1Mbps RS-232 Data Rates
Pin-Selectable 250kbps Slew Limiting
Single Supply Operation from 3V to 5.5V
1.65V to 5.5V Logic Interface V pin
L
The high speed drivers operate up to 20Mbps in RS-
485/422 modes, and up to 1Mbps in RS-232 mode.
All drivers can be slew limited to 250kbps in any
mode to minimize electromagnetic interference (EMI)
by setting the dedicated SLEW pin low.
2 Drivers, 2 Receivers RS-232/V.28
1 Driver, 1 Receiver RS-485/422
■ Full or Half Duplex Configuration
■ 1/8th Unit Load, up to 256 receivers on bus
All transmitter outputs and receiver inputs feature
robust electrostatic discharge (ESD) protection to
±15kV IEC 61000-4-2 Airgap, ±15kV Human Body
Model (HBM) and ±8kV IEC 61000-4-2 Contact. Each
receiver output has full fail-safe protection to avoid
system lockup, oscillation, or indeterminate states by
defaulting to logic-high output level when the inputs
are open, shorted, or terminated but undriven. No
external biasing resistors are required.
RS-485/422 Enhanced Receiver Fail-safe for open,
shorted, or terminated but idle inputs
10nA Shutdown Supply Current (typical)
Small 32 QFN package (5mm x 5mm)
TYPICAL APPLICATIONS
Software Programmable Serial Ports
The RS-232 receiver inputs include a 5k pull-down
to ground when in RS-232 mode. The RS-485/422
receiver inputs are high impedance (>96k when
termination is disabled), allowing up to 256 devices
on a single communication bus (1/8th unit load).
(RS-232, RS-422, RS-485)
Industrial and Single Board Computers
Industrial and Process Control Equipment
Point-Of-Sale Equipment
The SP335 operates from a single power supply,
either 3.3V or 5V, with low idle current. The shutdown
mode consumes less than 1µA in low power standby
operation with RS-232 receivers enabled.
HVAC Controls and Networking Equipment
Building Security and Automation
(1)
ORDERING INFORMATION
PART NUMBER
SP335EER1-L
OPERATING TEMPERATURE RANGE
LEAD-FREE
PACKAGE
PACKAGE METHOD
Tray
Reel
Tray
Reel
-40°C to +85°C
SP335EER1-L/TR
SP335ECR1-L
Yes(2)
32-pin QFN
0°C to +70°C
SP335ECR1-L/TR
SP335EER1-0A-EB
NOTES:
SP335E Evaluation Board
1. Refer to www.exar.com/SP335E for most up-to-date Ordering Information
2. Visit www.exar.com for additional information on Environmental Rating
1