MAX3485AEASA+ - 20Mbps 3.3V RS-485/RS-422 Transceiver | Analog Devices
料号： MAX3485AEASA+ ✓ 量产中MAX3485AEASA+ 概述
An RS-485/RS-422 transceiver is an interface IC that converts logic-level transmit and receive signals into differential bus voltages and back again. RS-485 supports balanced, multipoint communication over longer distances, while RS-422 provides a balanced differential link commonly used for point-to-point equipment connections. The MAX3485AEASA+ belongs to the interface IC hierarchy, where transceivers bridge communication processors, sensors, controllers, and industrial equipment connected by copper cabling.
The principal features of the MAX3485AEASA+ are its 20Mbps maximum signaling rate, 3V to 3.6V supply operation, half-duplex communication, and ±20kV ESD protection. Slew-rate limiting reduces high-frequency components generated by the driver and helps control EMI and cable reflections. These characteristics make the device useful where a conventional RS-485 transceiver would add excessive edge-rate energy to a long or noisy bus.
The device contains one differential driver and one differential receiver in a compact 8-SOIC package. A half-duplex architecture allows the same differential pair to support transmission and reception, which reduces connector and PCB routing requirements. Because the interface supports both RS-485 and RS-422 applications, the exact bus configuration and termination strategy must be selected according to the number of nodes, cable length, topology, and grounding arrangement used in the final system.
Typical uses include industrial supervisory control, factory automation, building controls, networked sensors, data-acquisition equipment, and point-to-point links between control electronics and remote instrumentation. In these systems, the transceiver can carry command, status, and measurement data over a differential cable while the 3.3V supply simplifies integration with low-voltage controllers. Long cables, connectors, and exposed installations also make the device's ±20kV ESD protection particularly relevant.
When laying out a board, place the transceiver close to the bus connector and keep the differential route short, continuous, and away from noisy switching paths. Termination, common-mode capacitors, and pull-up or pull-down components should be selected from the system-level RS-485 or RS-422 design rather than added solely by board population. The signal integrity of the complete bus depends on cable impedance, stubs, topology, and grounding in addition to the IC.
This product page combines the manufacturer's device description, verified distributor identification, package information, cross-reference options, and practical interface-design guidance. It distinguishes confirmed operating facts from parameters that still require board-level validation, helping engineers select the correct transceiver, compare pin-compatible devices, and plan a robust 3.3V differential communication link.
直接替换替代料： MAX3485AEASA+ ——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： MAX3485AEASA+ （相同外形与封装尺寸） ——差异在于 Package, Driver Count, Maximum Data Rate, Product Type, Receiver Count.
SP3485EN-L/TR
✅ 直接替换联系询价
查看数据手册 →SN75HVD3082E
✅ 直接替换📋 参考替代料（不在目录中）
SN65HVD485E
✅ 直接替换📋 参考替代料（不在目录中）
PCA82C250
✅ 直接替换📋 参考替代料（不在目录中）
ADM485ARZ-REEL
✅ 直接替换联系询价
查看数据手册 →ST3485E
✅ 直接替换📋 参考替代料（不在目录中）
MAX3485AEASA+ 规格参数
| Product Type | Half-duplex RS-485/RS-422 transceiver |
| Supply Voltage Range | 3V to 3.6V |
| Maximum Data Rate | 20Mbps |
| ESD Protection | ±20kV |
| Driver Count | 1 |
| Receiver Count | 1 |
| Communication Mode | Half-duplex |
| Supported Standards | RS-422 and RS-485 |
| Driver Slew Rate | Slew-rate limited |
| 封装 | 8-SOIC |
| 引脚数量 | 8 |
| 安装类型 | Surface mount |
| Cable Optimization | Extended cable runs |
| ESD Protection Level | ±20kV |
| Product Lifecycle | Production |
MAX3485AEASA+ 8-soic 引脚配置指南
MAX3485AEASA+（8-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： MAX3485AEASA+.
请参阅 数据手册 以查看完整引脚配置。
典型应用
MAX3485AEASA+ 适用于 6 应用s: Industrial Supervisory Control, Factory Automation Sensor Networks, Building Control Networks, Point-to-Point RS-422 Equipment Links, Data Acquisition and Instrumentation, Networked Sensors and Remote Actuation.
Industrial Supervisory Control
The MAX3485AEASA+ fits supervisory control links that distribute commands and collect status information between a controller and remote equipment over RS-485. Its 3V-to-3.6V operation supports 3.3V industrial control electronics, while the 20Mbps maximum data rate provides ample channel speed for short command and telemetry packets. Slew-rate-limited signaling reduces unwanted high-frequency energy on extended runs, and ±20kV ESD protection improves robustness at interfaces that may be exposed to electrostatic discharge. The transceiver should be placed near the connector, with controlled differential routing and termination selected according to the actual cable topology.
推荐
Factory Automation Sensor Networks
MAX3485AEASA+ can connect industrial sensors, remote I/O modules, and programmable controllers over a shared differential bus. The half-duplex architecture allows the same pair of conductors to support transmission and reception, reducing connector demand compared with separate full-duplex links. Its 20Mbps capability is useful when numerous nodes must exchange short packets, while the 3.3V supply range aligns with modern embedded control systems. The ±20kV ESD rating is relevant to factory wiring that crosses between cabinets. Bus loading, termination, and common-mode behavior must be validated together because transceiver specifications alone do not define the network's maximum node count or cable length.
推荐
Building Control Networks
The MAX3485AEASA+ is suitable for building-management equipment that exchanges thermostat, lighting-control, access-control, and equipment-status data over an RS-485 network. Its low 3.3V supply requirement simplifies integration with embedded controllers, and the 20Mbps signaling rate provides more bandwidth than required for typical command traffic. Slew-rate limiting helps preserve signal quality on cables installed between equipment rooms, while ±20kV ESD protection adds useful robustness at accessible connectors. Installation practice remains critical: maintain one ground reference where required, avoid parallel cable runs, use appropriate termination, and keep the transceiver and protection components close to the entry point.
推荐
Point-to-Point RS-422 Equipment Links
MAX3485AEASA+ can implement a point-to-point RS-422 link between two pieces of equipment that require differential signaling, such as a data-acquisition unit and a remote controller. The 20Mbps capability supports considerably faster data transfer than low-speed control transceivers, while the 3V-to-3.6V supply range permits operation alongside 3.3V digital circuitry. The integrated driver and receiver simplify implementation, and ±20kV ESD protection strengthens the interface against electrostatic discharge at equipment boundaries. For a successful link, the designer should preserve differential impedance through the PCB and cable, provide suitable termination, and confirm that the grounding arrangement satisfies the selected RS-422 system configuration.
推荐
Data Acquisition and Instrumentation
The MAX3485AEASA+ fits instrumentation systems that transfer sampled measurements, configuration commands, and diagnostic records between a host and remote test equipment. The 3.3V operating range supports compact embedded instruments, and the 20Mbps rate allows high data density without requiring a separate high-voltage transceiver supply. Slew-rate-limited drive helps manage reflections, and ±20kV ESD protection is beneficial when measurement cables connect to external equipment. Designers should keep analog and power sections away from the bus traces, provide a continuous ground reference, and evaluate the cable's attenuation and impedance. The exact maximum communication distance depends on the complete system rather than on the transceiver's headline data rate.
推荐
Networked Sensors and Remote Actuation
MAX3485AEASA+ supports remote sensor and actuator networks that use a controller to poll distributed modules over RS-485. The 20Mbps maximum rate provides ample payload capacity for frequent short frames, while half-duplex operation limits the number of bus conductors required. A 3.3V supply simplifies deployment in compact sensor electronics, and ±20kV ESD protection is useful for installations with user-accessible wiring. The bus should be designed as a controlled transmission-line environment, with minimal stubs, deliberate termination locations, and adequate common-mode margin. If the network experiences reflections or inconsistent logic levels, check the topology, cable type, termination, grounding, and node loading before changing the transceiver.
推荐
推荐产品汇总
工程参考数据： MAX3485AEASA+ ——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 | SP3485EN-L/TR | SN75HVD3082E | SN65HVD485E | PCA82C250 | ADM485 | ST3485E |
|---|---|---|---|---|---|---|---|
| Package | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC |
| Brand | Analog Devices | MaxLinear, Inc. | Texas Instruments | Texas Instruments | NXP Semiconductors | Analog Devices | STMicroelectronics |
关键差异点
- High signaling rate in an 8-SOIC interface IC （对比 SP3485EN-L/TR)
- Documented high-level ESD robustness （对比 SN75HVD3082E)
- Combined RS-485 and RS-422 operation （对比 PCA82C250)
设计说明
Place the MAX3485AEASA+ near the RS-485 or RS-422 connector and route the differential pair as a continuous impedance-controlled pair over a solid ground plane. Avoid routing the bus through digital clocking areas, switching regulators, and high-current return paths. Keep the driver and receiver traces away from antenna-like stubs, and preserve the intended differential geometry through connector launches and protection-device locations.
Treat the cable and PCB interconnect as a transmission line. For the MAX3485AEASA+'s 20Mbps capability, verify propagation delay, connector and protection-device capacitance, stub lengths, and the loss of the selected cable. Add termination only where the topology requires it. If reflections or inconsistent differential levels appear, inspect node count, cable impedance, grounding, and termination before attributing the behavior to the transceiver.
Do not infer that identical SOIC-8 packages guarantee identical behavior. Before replacing the MAX3485AEASA+, compare the alternative's pin function, supply range, maximum data rate, receiver thresholds, fail-safe behavior, driver enable polarity, and ESD rating against the system requirement. In half-duplex designs, also verify that the controller handles bus turnaround correctly and that no unwanted driver state occurs during reception.
合规信息
The manufacturer product page identifies production status and the 3.3V RS-485/RS-422 product family, but the available product information does not explicitly state the requested environmental and material-compliance declarations.