ADM485JR - 5Mbps RS-485/422 Transceiver | Analog Devices
MPN： ADM485JR ✓ 啟用中ADM485JR 概覽
An RS-485 transceiver is an interface IC that converts logic-level digital signals into balanced differential signals for reliable communication over noisy or long cable runs. In the signal-chain hierarchy, it belongs to the RS-485/RS-422 interface transceiver category within integrated interface circuits. Its differential signaling improves noise immunity by representing the transmitted signal as the voltage difference between two conductors.
Key features include support for data rates up to 5 Mbit/s, a 5 V supply, low-power operation, and independently enabled driver and receiver sections. The fast switching performance minimizes propagation-delay mismatch and skew, helping reduce EMI on high-speed buses. The device is also specified over commercial and industrial temperature ranges and is available in an 8-pin DIL or SOIC package family.
The ADM485 architecture includes a differential line driver with dedicated outputs and a differential line receiver with dedicated inputs. Independent enable control allows a node to remain transparent, transmit only, receive only, or support half-duplex bus operation. This flexibility makes the transceiver suitable for multipoint communication where bus direction and node participation must be controlled independently.
Typical uses include industrial automation equipment, building-control networks, instrumentation, data acquisition, computer interfaces, and communication links between distributed modules. At 5 Mbit/s, the part can support high-speed balanced data transfer, while the 8-pin SOIC package simplifies assembly on conventional surface-mount PCB designs.
Designers should pay attention to termination, biasing, common-mode range, and transceiver enable timing. The manufacturer datasheet also discusses excessive power dissipation caused by bus contention or output shorting, making it important to prevent multiple enabled drivers from driving the bus at the same time. Cable length, topology, and transceiver speed must be considered together because high data rates generally require shorter, better-controlled buses.
This page consolidates the verified manufacturer information, distributor pricing, replacement considerations, and application-specific engineering guidance into one practical reference for engineers evaluating the ADM485JR.
直接替換替代品，適用於 ADM485JR — 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： ADM485JR （相同外形與佔位） — 差異在於 Package, Maximum Data Rate, Product Type, Supply Voltage.
ADM485JRZ
✅ 直接替換聯絡詢價
查看資料表 →ADM485ARZ
✅ 直接替換聯絡詢價
查看資料表 →ADM485EJRZ
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
ADM485EARZ
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
ADM485JR 規格
| Product Type | Low-power differential line transceiver |
| 供應電壓 | 5 V |
| Maximum Data Rate | 5 Mbit/s |
| Communication Standards | EIA RS-485 and EIA RS-422 |
| Driver Configuration | Differential line driver |
| Receiver Configuration | Differential line receiver |
| Enable Control | Independent driver and receiver enables |
| Bus Mode | Multipoint, full-duplex, or half-duplex communication |
| 封裝 | 8-pin SOIC |
| Package Family | 8-pin DIL or SOIC |
| 安裝類型 | Surface mount |
| Temperature Qualification | Commercial and industrial temperature ranges |
| Power Class | Low power |
| EMI Characteristic | Low channel skew |
ADM485JR 腳位配置
| 腳位 1 | RO — Receiver output |
| 腳位 2 | RE — Receiver enable, active low |
| 腳位 3 | DE — Driver enable, active high |
| 腳位 4 | DI — Driver data input |
| 腳位 5 | GND — Ground |
| 腳位 6 | A — Non-inverting driver output and receiver input |
| 腳位 7 | B — Inverting driver output and receiver input |
| 腳位 8 | VCC — Positive supply |
典型應用
ADM485JR 適用於 6 應用s: Industrial Automation RS-485 Bus, Building Control and HVAC Networking, Data Acquisition and Instrumentation, Computer-to-Equipment Peripheral Link, Security and Surveillance Equipment, Remote Sensor and Actuator Networks.
Industrial Automation RS-485 Bus
The ADM485JR fits industrial automation bus nodes because it combines a 5 V supply with differential RS-485 communication up to 5 Mbit/s. The balanced interface helps reject common-mode noise encountered around motors, relays, contactors, and long factory wiring. Independent driver and receiver enables allow a controller to transmit commands and receive responses without tying bus direction to the logic source. Designers should place termination and fail-safe biasing according to the bus topology, avoid multiple drivers becoming active simultaneously, and verify the cable length against the selected 5 Mbit/s data rate.
推薦
Building Control and HVAC Networking
The ADM485JR is appropriate for building-control equipment that connects sensors, controllers, and actuators over a wired RS-485 segment. Its 5 V low-power operation supports compact equipment, while differential signaling improves immunity to the electrical noise commonly found near HVAC drives and power relays. The 5 Mbit/s capability provides ample data-rate margin for supervisory control data and can simplify one physical network spanning multiple controller types. Firmware and hardware must still coordinate driver-enable states to prevent bus contention, and grounding and surge protection should be evaluated for long building runs.
推薦
Data Acquisition and Instrumentation
The ADM485JR can connect laboratory or industrial instrumentation to a host over RS-485, allowing measurement equipment to extend beyond a short board-level interface. The differential receiver is well suited to systems in which source devices are separated from the controller by several metres of cable. At 5 Mbit/s and 5 V, the transceiver provides a useful combination of speed and low-power operation for compact acquisition modules. The bus design must include appropriate termination and fail-safe biasing, and the firmware needs a defined arbitration or token-passing method when multiple measurement nodes can transmit.
推薦
Computer-to-Equipment Peripheral Link
The ADM485JR provides a simple interface between a host controller and industrial peripheral equipment using an RS-485 balanced pair. Its 5 Mbit/s capability allows rapid command and response traffic, while the low-power 5 V architecture suits embedded and compact control equipment. The independent receiver and driver enables are useful when the peripheral must remain available to receive during firmware updates or when a host needs a listen-only state. A robust implementation requires correct logic-level mapping, deliberate DE and RE control, adequate common-mode grounding, and protection appropriate to the external cable environment.
推薦
Security and Surveillance Equipment
The ADM485JR can be used in surveillance equipment that distributes commands or status between cameras, access-control units, and a central controller. Balanced differential signaling helps maintain reliable communications when the equipment is installed alongside switching power supplies and other electrically noisy systems. The 5 Mbit/s rate supports rapid status updates, and the low-power 5 V operation is useful for compact camera or access-control electronics. Engineers should isolate the communications bus from ground differences, apply surge protection at exposed cable entries, and ensure that firmware prevents two remotely located devices from driving the bus simultaneously.
推薦
Remote Sensor and Actuator Networks
The ADM485JR is well suited to remote sensor and actuator networks because a balanced bus can connect multiple low-power field nodes over a shared cable. The 5 V transceiver operates at rates up to 5 Mbit/s, allowing the network to carry frequent measurements and control responses without requiring a separate communication link for every device. Independent driver and receiver enables support half-duplex operation and permit listen-only diagnostics. Bus polarity, grounding, termination, and fail-safe biasing must be planned as a complete system, while enclosure surge protection is important when sensors are connected to long outdoor cables.
推薦
推薦產品摘要
工程參考資料，適用於 ADM485JR — 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 | ADM485JRZ | ADM485ARZ | ADM485EJRZ | ADM485EARZ |
|---|---|---|---|---|---|
| Package | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC | 8-pin SOIC |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Supply Voltage | 5 V | 5 V | 5 V | 5 V | 5 V |
| Maximum Data Rate | 5 Mbit/s | 5 Mbit/s | 5 Mbit/s | 5 Mbit/s | 5 Mbit/s |
| Communication Standards | RS-485 and RS-422 | RS-485 and RS-422 | RS-485 and RS-422 | RS-485 and RS-422 | RS-485 and RS-422 |
| Driver and Receiver Enables | Independent | Independent | Independent | Independent | Independent |
主要差異化特點
- High-speed differential bus operation in a compact package (對比ADM485JRZ)
- Independent driver and receiver enable control (對比ADM485ARZ)
- Potential fail-safe enhancement (對比ADM485JR)
設計說明
Prevent bus contention by ensuring that only one ADM485JR driver is enabled while another node transmits. The Analog Devices manufacturer datasheet identifies excessive power dissipation caused by bus contention and output shorting as a primary hazard. In firmware, use a deterministic arbitration or token-passing scheme, disable the driver promptly after transmission, and provide a defined safe state if the controlling microcontroller resets.
Route the A and B conductors as a tightly coupled differential pair with continuous ground reference beneath or adjacent to the pair. Place the receiver and transceiver grounding strategy consistent with the manufacturer reference circuit, keep the logic-side traces short, and position termination only at the physical ends of the bus. Avoid routing the balanced pair through switching-power or relay regions because that undermines the noise rejection advantage of differential signaling.
Treat termination, biasing, cable length, and data rate as one linked design problem. Although the ADM485JR supports 5 Mbit/s, a long cable or unterminated branch can introduce reflections and reduce reliable margin. Use the manufacturer's application guidance to select termination and fail-safe biasing for the topology, minimize stubs, and verify operation with oscilloscope measurements at the far end under worst-case loading.
合規資訊
The supplied verified snippets did not provide authoritative compliance statements for the ADM485JR. These fields remain unknown rather than being inferred from the manufacturer or distributor listings.