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 used interchangeably over a single cable or connector with no additional switching components. Full operation requires only four external charge pump capacitors.
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 120Ω termination, and the HALF/FULL pin configures the transceiver as either half or full duplex.
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.
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.
The RS-232 receiver inputs include a 5kΩ pull-down to ground when in RS-232 mode. The RS-485/422 receiver inputs are high impedance (>96kΩ when termination is disabled), allowing up to 256 devices on a single communication bus (1/8th unit load).
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.
- Pin-Selectable Cable Termination
- No External Resistors Required for RS-485/422 Termination or Biasing
- Robust ESD Protection:
- ±15kV IEC 61000-4-2 Air Gap Discharge
- ± 8kV IEC 61000-4-2 Contact Discharge
- ±15kV Human Body Model (HBM)
- 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 VL pin
- 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
- 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)
- Software Programmable Serial Ports (RS-232, RS-422, RS-485)
- Industrial and Single Board Computers
- Industrial and Process Control Equipment
- Point-Of-Sale Equipment
- HVAC Controls and Networking Equipment
- Building Security and Automation
Parts & Purchasing
|Part Number||Pkg Code||RoHS||Min Temp||Max Temp||Status||Buy Now||Order Samples|
|SP335ECR1-L||QFN32 5x5 OPT3||0||70||Active||Order|
|SP335ECR1-L/TR||QFN32 5x5 OPT3||0||70||Active||Order|
|SP335EER1-L||QFN32 5x5 OPT3||-40||85||Active||Order|
|SP335EER1-L/TR||QFN32 5x5 OPT3||-40||85||Active||Order|
Active - the part is released for sale, standard product.
EOL (End of Life) - the part is no longer being manufactured, there may or may not be inventory still in stock.
CF (Contact Factory) - the part is still active but customers should check with the factory for availability. Longer lead-times may apply.
PRE (Pre-introduction) - the part has not been introduced or the part number is an early version available for sample only.
OBS (Obsolete) - the part is no longer being manufactured and may not be ordered.
NRND (Not Recommended for New Designs) - the part is not recommended for new designs.
Frequently Asked Questions
For RS-232 it is 50 feet (15 meters), or the cable length equal to a capacitance of 2500 pF, at a maximum transmission rate of 19.2kbps. When we reduce the baud rate, it allows for longer cable length. For Example:
Baud Rate (bps)
Maximum RS-232 Cable Length (ft)
No, the maximum fault tolerance of the above devices is ±18V only. However, the XR3305x and XR3315x families DO support up to ±60V fault tolerance. To find the device in the XR3305x and XR3315x families with the configuration you are looking for, use the parametric search https://www.exar.com/products/interface/serial-transceivers/rs485-422. The Fault Tolerance column is on the right side of the table. See the filters on the left for device selection. See Application Note ANI-23 https://www.exar.com/ani-23.pdf for more on fault testing of these devices.
For any voltage above ±60V, refer to diode manufacturers, such as the Bourns RS-485 transient protection for example below, for an external diode to absorb the transient or surge voltage for protection.or
In this example, we looked for XRA1201. When you hover over it, it will turn grey and you can click anywhere in the grey box. This brings you to the product page. For example:
Click on Parts & Purchasing, highlighted in yellow above. The screen changes to:
Notice the status column and the “Show obsolete parts” link:
A legend tells you the definition of the different statuses. Click on the “Show obsolete parts” link to see EOL or OBS part numbers along with the Active part numbers:
Another method to find out if a part is OBS or EOL is to click on SUPPORT:
And then Product Change Notifications
Type the part into the search, and click on one of the part numbers from the drop down menu. Then you can look for the Product Discontinuation Notice, which generally is at the top of the list, for example:
If you see this, it tells you that this particular orderable part has been discontinued and when the last order date is, or was. If you click on the file, then you can view the notice we sent about this if you purchased the part in the recent past. It may also advise of a replacement part. When an orderable part first becomes discontinued, Product Discontinuation Notices are sent are sent to those who have purchased the parts in the recent past, if purchased directly, with a dated opportunity to place a last order.