SP485RCN/TR - 1/10 Unit Load RS-485 Transceiver | Sipex
料号： SP485RCN/TR ✓ 量产中SP485RCN/TR 概述
An RS-485 transceiver is a physical-layer interface integrated circuit that combines a differential line driver with a differential receiver. It belongs to the hierarchy of RS-485 interface IC, communications transceiver, interface IC, and semiconductor. This combination supports bidirectional data transfer over a balanced pair of wires while providing the common-mode tolerance and loading characteristics required for distributed industrial buses.
The SP485RCN/TR's 1/10-unit-load receiver input is its defining network-loading feature. Unlike a standard-unit-load device, it reduces the loading presented by each connected node, allowing more than 400 transceivers to share a transmission line. Its typical 150 kΩ receiver input impedance helps preserve signal integrity when multiple nodes are connected, while its +12 V common-mode input range supports systems in which the bus voltage can move substantially above the receiver reference ground.
The SP485R architecture provides a half-duplex transceiver arrangement in which one interface is used for transmission and reception. Direction control allows the connected controller or transceiver to determine when the driver is active. This arrangement is suited to bus architectures where devices share the same differential pair and transmit in a controlled sequence, avoiding simultaneous bus contention.
Typical uses include industrial process-control networks, factory automation equipment, building-control systems, instrumentation, and other multidrop RS-485 networks. The reduced unit load is particularly useful where many field devices must share one cable run. The SP485RCN/TR is also suitable for systems that need the extended common-mode input range of +12 V.
PCB design should preserve the differential signal path from the transceiver through the connector, maintain closely matched routing for the A and B conductors, and provide a suitable return path to reduce common-mode conversion. Bus topology, termination, fail-safe biasing, and protection requirements must be evaluated at the network level because correct transceiver selection alone does not guarantee reliable communication.
This page combines the device's RS-485 network-loading characteristics with practical application guidance, interface comparisons, pinout-document links, and design notes for engineers evaluating the SP485RCN/TR in multidrop industrial communication systems.
直接替换替代料： SP485RCN/TR ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： SP485RCN/TR （相同外形与封装尺寸） ——差异在于 Transceiver Type, Maximum Data Rate, Operating Temperature Range, Supported Standards.
SP485RCN-L/TR
✅ 直接替换联系询价
查看数据手册 →SP485EEN-L/TR
✅ 直接替换联系询价
查看数据手册 →SP485CN-L/TR
✅ 直接替换 ⚠️ 规格未核验联系询价
查看数据手册 →SP485RCN/TR 规格参数
| Transceiver Type | 1 Transceiver, Half Duplex |
| Supported Standards | RS-422, RS-485 |
| Receiver Unit Load | 1/10 unit load |
| Maximum Transceivers per Transmission Line | More than 400 transceivers |
| Receiver Input Impedance | 150 kΩ typical |
| Common-Mode Input Voltage Range | Up to +12 V |
| 封装 | 8-pin SOIC |
| 安装类型 | Surface mount |
| Direction Control | Half-duplex driver/receiver |
| Driver and Receiver Count | 1 driver, 1 receiver |
SP485RCN/TR 8-pin soic 引脚配置指南
SP485RCN/TR（8-pin soic 封装）的引脚配置。 引脚编号、功能和连接图在制造商数据手册中定义。请参阅该手册以了解确切的封装尺寸和焊接指南。
暂无详细引脚数据： SP485RCN/TR.
请参阅 数据手册 以查看完整引脚配置。
典型应用
SP485RCN/TR 适用于 6 应用s: Industrial Process-Control Networks, Factory Automation Equipment, Building-Control and HVAC Systems, Instrumentation and Test Systems, Telecommunications Remote Units, Security and Access-Control Systems.
Industrial Process-Control Networks
The SP485RCN/TR fits multidrop process-control buses where many field devices share one twisted pair. Its 1/10-unit-load receiver input allows more than 400 transceivers on a transmission line, reducing the load accumulated across the network compared with a standard one-unit-load interface. The common-mode input range extending to +12 V also gives the receiver additional tolerance when bus voltages differ from local ground. Place the transceiver near the field connector, route the A and B pair as a tightly coupled differential pair, and verify the complete node budget, cable length, termination, and protection network before deployment.
推荐
Factory Automation Equipment
The SP485RCN/TR is appropriate for factory automation controllers, motor-control panels, and remote I/O modules using half-duplex RS-485. The single-driver, single-receiver arrangement supports economical shared-bus wiring, while the 1/10-unit-load input provides additional node-count margin over standard-unit-load transceivers. Its 150 kΩ typical receiver input impedance helps limit loading when several modules connect to the same cable. Direction-control logic should be connected so that only one node drives the bus at a time. Protective components and chassis-ground design must be evaluated separately for industrial surge, burst, and ESD requirements.
推荐
Building-Control and HVAC Systems
The SP485RCN/TR can connect HVAC controllers, room sensors, actuators, and supervisory units that communicate over an RS-485 backbone. Its 1/10-unit-load receiver input supports a large multipoint population, while the +12 V common-mode range adds tolerance for installations where the bus common voltage moves relative to controller ground. A single twisted pair reduces wiring cost compared with separate point-to-point links. The design should include defined cable routing, bus-end termination, fail-safe biasing at a defined location, and surge protection for long building branches exposed to lightning or switching transients.
推荐
Instrumentation and Test Systems
The SP485RCN/TR is useful in laboratory and field instrumentation where multiple measurement modules share an RS-485 command bus. The high fan-out capability minimizes the burden imposed by each receiver, and the half-duplex arrangement simplifies command-and-response traffic. Its common-mode input rating extending to +12 V helps accommodate grounded measurement systems with different local reference potentials. For test equipment, add an isolated interface or suitable protection when users can connect external cables. Validate data integrity at the longest supported cable length, the highest intended baud rate, and the maximum planned node population.
推荐
Telecommunications Remote Units
The SP485RCN/TR can serve as the local bus interface inside telecommunications remote units, outdoor monitoring cabinets, and line-powered equipment. Its 1/10-unit-load receiver input accommodates dense multidrop deployments, and the 8-pin SOIC package supports compact surface-mounted assemblies. The +12 V common-mode input capability is useful where ground offsets are present between cabinets and central equipment. Designers should add surge and lightning protection at exposed cable entries, use isolated supplies where required, and route the differential pair away from switching nodes to reduce converted common-mode noise.
推荐
Security and Access-Control Systems
The SP485RCN/TR is suitable for access-control readers, door controllers, alarm panels, and cameras connected through an RS-485 backbone. The reduced receiver loading permits a larger population of distributed nodes, while the common-mode range supports installations with varied grounding. Direction control allows the controller to issue commands and collect responses over the same pair. For security equipment, maintain a controlled bus topology, use reliable surge protection at perimeter cables, and consider isolation where outdoor units share ground with different systems. Signal routing should remain short, symmetric, and away from switching regulators and high-current relay returns.
推荐
推荐产品汇总
工程参考数据： SP485RCN/TR ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | SP485RCN-L/TR | SP485EEN-L/TR | SP485CN-L/TR |
|---|---|---|---|---|
| Brand | Sipex Corporation | MaxLinear, Inc. | MaxLinear, Inc. | MaxLinear, Inc. |
| Package | 8-pin SOIC | 8-pin SOIC - same | 8-pin SOIC - same | 8-pin SOIC - same |
| Transceiver Configuration | Half-duplex RS-485 transceiver | Half RS-422/RS-485 transceiver | Half-duplex RS-485 transceiver | RS-485 transceiver |
| Receiver Unit Load | 1/10 unit load | 1/10 unit load | 1/10 unit load | 1/10 unit load |
| Half-Duplex Operation | Yes | Yes | Yes | Yes |
关键差异点
- High bus fan-out capability （对比 SP485RCN-L/TR)
- Extended positive common-mode input range （对比 SP485EEN-L/TR)
- Documented receiver loading （对比 SP485CN-L/TR)
设计说明
Route the A and B conductors as a tightly coupled differential pair from the SP485RCN/TR to the connector. Keep the pair length matched, avoid routing over discontinuous plane references, and place termination, protection, and optional fail-safe biasing close to the connector where practical. Do not create a star topology, because branch stubs can create reflected signals and reduce the reliability of a large multipoint network.
The 1/10-unit-load rating reduces receiver loading but does not eliminate system-level bus calculations. Include the complete transceiver count, cable attenuation, connector loss, termination, node biasing, and transceiver tolerances when estimating the supported node population and cable length. Also verify that the bus remains within the +12 V common-mode input boundary and that only one node drives the line during each transmission interval.
Keep the direction-control and data-interface traces away from the RS-485 A and B pair, especially around switching regulators, relays, and inductors. Use a continuous ground reference beneath the interface where the board stackup permits it, and place supply-decoupling capacitors next to the device. If the cable leaves the enclosure, add appropriately rated surge and ESD protection and verify that its capacitance does not degrade edge-rate performance.
合规信息
Compliance status must be confirmed from the current manufacturer declaration or product documentation for the exact SP485RCN/TR ordering code.