SP3485EEN(UMW)

The SP3485E is a 3.3V-powered, half-duplex, low-power RS-485 transceiver that fully complies with TIA/EIA-485 standard requirements. The SP3485E integrates one driver and one receiver, both of which can be independently enabled and disabled. When both are disabled, the driver and receiver outputs enter a high-impedance state. The SP3485E features 1/8 unit load, allowing up to 256 SP3485E transceivers to be connected to the same communication bus. Error-free data transmission at up to 12Mbps is achievable. The SP3485E operates over a supply voltage range of 3.0V to 3.6V, and provides fault protection, over-temperature protection, current limiting protection, and overvoltage protection.

Applications

• Bus Networking: The SP3485E RS485 transceiver is designed for bidirectional data communication on multipoint bus transmission lines. These devices can also be used as line repeaters for cable lengths exceeding 4000 feet. To reduce reflections, termination matching using the characteristic impedance should be applied at both ends of the transmission line, and stub lengths beyond the main line should be kept as short as possible.
• Daisy-Chain Networking: Also known as daisy-chain topology, this is the standard and recommended RS485 bus wiring topology endorsed by organizations such as TIA. The wiring method connects a master device and multiple slave devices in a daisy-chain configuration. This approach has no stubs, offering the advantages of low signal reflection and high communication success rate.
• Bus Port Protection: In harsh environments, RS485 communication ports typically require protection against ESD, lightning, and surge, and may even need to withstand 380V power line contact, to prevent damage to smart meters and industrial control hosts.

Key features

• 3.3V supply, half-duplex
• 1/8 unit load, supports up to 256 devices on the bus
• Driver output short-circuit protection
• Over-temperature protection
• Low-power shutdown
• Receiver open-circuit protection
• High noise immunity
• Integrated transient voltage suppression