ADM485AN - 5V RS-485/RS-422 Transceiver | Analog Devices
MPN： ADM485AN ✓ 啟用中ADM485AN 概覽
An RS-485 transceiver is an interface IC that converts logic-level digital signals into balanced differential signals for reliable communication over longer cables and noisy industrial environments. Its differential signaling improves noise immunity, enables bidirectional half-duplex buses, and supports multiple nodes when the complete bus is properly terminated and biased. The RS-422 capability provides another balanced-line interface option for point-to-point or multidrop systems.
The ADM485 family is specified for both commercial and industrial temperature operation. Key application benefits include a maximum data rate of 5 Mbit/s, low-power 5 V operation, and fast switching. The ADM485AN uses the N-tube PDIP-8 package identified in distributor data, making it suitable for conventional through-hole PCB assembly rather than surface-mount production.
In a typical bus design, the transceiver connects a microcontroller UART to an A and B differential pair. The logic-side supply operates from 5 V, and a driver-enable signal controls whether the transmitter or receiver participates in bus communication. Receiver enable may be managed by the same control signal for half-duplex operation, or controlled separately where full-duplex behavior is required.
Proper RS-485 implementation depends on more than substituting the IC. The differential pair should be routed as a controlled-impedance cable connection, the transceiver ground reference must be managed carefully, and only the intended endpoint terminations should be installed. External protection may be needed when exposed cables carry electrostatic discharge or surge events.
This page combines verified manufacturer and distributor information with practical interface guidance, replacement criteria, and design cautions. The ADM485AN should be selected when an 8-pin through-hole RS-485/RS-422 transceiver is required and its documented 5 Mbit/s capability matches the intended bus length, topology, noise environment, and system timing.
直接替換替代品，適用於 ADM485AN — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： ADM485AN （相同外形與佔位） — 差異在於 Mounting Type, Communication Mode, Maximum Data Rate, Operating Temperature Range, Package.
ADM485JNZ
✅ 直接替換聯絡詢價
查看資料表 →ADM485JRZ-REEL7
✅ 直接替換📋 參考替代品（不在目錄中）
ADM485AN 規格
| Product Type | Single RS-485/RS-422 differential line transceiver |
| 供應電壓 | 5 V |
| Maximum Data Rate | 5 Mbit/s |
| Supported Standards | EIA RS-485 and RS-422 |
| Transmitter and Receiver Count | 1 transmitter and 1 receiver |
| Communication Mode | Bidirectional data communication |
| Bus Topology | Multipoint bus transmission lines |
| 封裝 | 8-pin PDIP N tube |
| 安裝類型 | Through-hole |
| 工作溫度範圍 | Commercial and industrial ranges |
ADM485AN 8-pin pdip n tube 腳位配置指南
ADM485AN（8-pin pdip n tube 封裝）的腳位配置。 腳位編號、功能與連接圖定義於製造商資料手冊中。請參閱該手冊以取得確切的封裝尺寸與焊接指引。
無詳細腳位定義資料： ADM485AN.
請參閱 資料表 以查看完整腳位配置。
典型應用
ADM485AN 適用於 7 應用s: Industrial RS-485 Control Bus, Building Automation and HVAC Network, Instrumentation and Data Acquisition, RS-422 Point-to-Point Link, Remote Sensor and Telemetry Link, Industrial Gateway with UART-to-RS485 Conversion, Automotive or Heavy Equipment Diagnostic Interface.
Industrial RS-485 Control Bus
ADM485AN fits industrial control equipment that links a controller to remote sensors, actuators, motor starters, or remote I/O over a balanced RS-485 bus. Its verified 5 Mbit/s capability provides timing margin for many short industrial links, while differential signaling improves common-mode-noise immunity. The designer should match the UART baud rate to the cable length and topology, use termination only at the physical endpoints, and provide fail-safe biasing where required. The 8-pin PDIP package also suits repairable or manually assembled industrial controller boards.
推薦
Building Automation and HVAC Network
The ADM485AN can connect a building controller to distributed HVAC units, room sensors, dampers, or variable-air-volume equipment using an RS-485 network. The transceiver's balanced differential interface is useful in buildings where motors, relays, and long cable runs create electrical noise. Its verified 5 Mbit/s maximum rate is not the only system limit: cable length, topology, shielding, grounding, and termination determine the practical communication rate. Firmware should also handle bus contention, node addressing, and retry behavior.
推薦
Instrumentation and Data Acquisition
ADM485AN is appropriate for laboratory and field instrumentation where a central data-acquisition unit must receive measurements from multiple remote modules. The receiver converts the balanced bus signal into a logic-level input for a microcontroller or processor, while the transmitter supports command traffic. The verified data does not specify receiver sensitivity or common-mode limits, so these parameters must be checked in the official datasheet before selecting it for long cables or electrically noisy installations.
推薦
RS-422 Point-to-Point Link
Although commonly associated with RS-485, ADM485AN also supports RS-422 balanced-data operation and can be considered for point-to-point or multidrop links when the system requirements match the transceiver's documented electrical behavior. The differential line reduces susceptibility to common-mode noise compared with a single-ended interface. Designers must verify the selected ADM485AN variant's RS-422 configuration, termination strategy, and logic-side pinout against the official datasheet rather than assuming every RS-485 transceiver is optimal for RS-422.
推薦
Remote Sensor and Telemetry Link
ADM485AN can connect a remote sensor node to a central logger over a wired differential bus. Its verified 5 Mbit/s class is suitable for sensor data when the physical network can support that rate, although practical industrial links are often limited more by distance and topology than by the IC. Use twisted-pair cabling, controlled routing, proper reference grounding, and endpoint termination. For low-power nodes, the component's actual supply-current specification must be obtained from the manufacturer datasheet before battery-budget calculations are made.
推薦
Industrial Gateway with UART-to-RS485 Conversion
ADM485AN is a natural interface between a conventional UART and a wired RS-485 fieldbus in gateway equipment. The microcontroller supplies transmit and receive logic, while the transceiver drives the balanced pair and receives bus data. Direction control must account for driver-enable latency and bus turnaround time. Because the verified data does not specify propagation delay or output-current limits, an engineer should use the current Analog Devices documentation to establish timing and load-current margins before selecting cable length and node count.
推薦
Automotive or Heavy Equipment Diagnostic Interface
ADM485AN may be considered for heavy-equipment diagnostic or service interfaces where a controller communicates with remote nodes over a wired balanced bus. The verified sources do not claim AEC-Q100 qualification, automotive temperature grade, surge protection, or transient immunity, so it should not be placed in a safety-critical automotive design without qualification evidence. At minimum, review the operating-temperature range, ESD rating, common-mode limits, and fault behavior in the current manufacturer datasheet and add appropriate cable protection.
推薦
推薦產品摘要
工程參考資料，適用於 ADM485AN — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | ADM485JNZ | ADM485JRZ-REEL7 | SN75176BD |
|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Texas Instruments |
| Product Type | RS-485/RS-422 transceiver | RS-485/RS-422 transceiver | RS-485/RS-422 transceiver | RS-485 transceiver family |
主要差異化特點
- Verified 5 Mbit/s high-speed capability (對比SN75176BD)
- Dual RS-485 and RS-422 support (對比ADM485JNZ)
- Through-hole package for legacy PCB assembly (對比ADM485JRZ-REEL7)
- One-transmitter, one-receiver integrated interface (對比SN75176BD)
設計說明
Route the A and B differential pair as a closely coupled pair, preferably over a continuous reference plane, and keep the pair away from switching nodes, clocks, and high-current motor paths. The verified data does not provide a recommended PCB land pattern or trace geometry, so use the official ADM485AN package drawing and the cable manufacturer's guidance rather than copying an unverified footprint. Keep the transceiver close to the connector and place protection components near the cable entry.
Do not assume that any RS-485-family IC is a drop-in replacement. Verify the 8-pin PDIP footprint, numbered pinout, supply pins, driver-enable polarity, receiver-enable behavior, and common-mode limits. The verified data supports ADM485AN's RS-485/RS-422 function and 5 Mbit/s capability, but it does not provide enough electrical detail to approve every cross-reference candidate. Treat SN75176BD and other family alternatives as design-review candidates until their manufacturer documentation is checked.
For an RS-485 network, use twisted-pair cable, terminate the differential line only at the physical endpoints, and apply biasing only when the selected transceiver family requires it. A termination resistor at every node can over-damp the bus and reduce signal margin. Start-rate validation with the longest cable, intended node count, grounding arrangement, and worst-case transceiver loading; the IC's 5 Mbit/s headline rate is not a substitute for system-level signal-integrity validation.
The ADM485AN is an interface IC rather than a power semiconductor, so a safe-operating-area curve is not applicable. Nevertheless, power dissipation depends on supply voltage, driver load, termination, and data activity. The supplied data does not include current consumption or output-current limits, so calculate dissipation from the current Analog Devices datasheet and confirm the package temperature rise using the actual PCB copper area and ambient temperature.
合規資訊
The supplied verified data identifies EIA RS-485 and RS-422 compliance but does not provide verified RoHS, REACH, lead-free, halogen-free, conflict-minerals, or automotive qualification information. The ADI product family is specified over commercial and industrial temperature ranges, but that statement is not an automotive qualification claim.
