Le blog de l'entreprise ADI ADM2481 Supply—2.5 kV Isolated RS-485 Transceiver for Industrial Automation and Building Control

In industrial automation, building control, and multi-point data transmission systems, the reliability and security of communication interfaces directly determine whether a system can operate stably over the long term. Mingjiada Electronics now offers brand-new, genuine ADI (Analog Devices) ADM2481 isolated RS-485 transceivers in stock. With core features including 2.5 kV signal isolation, a 500 kbps data rate, and ultra-low power consumption of 2.5 mA, this device serves as an ideal communication solution for industrial fieldbuses, isolated interfaces, and building control networks.

I. Product Introduction

The ADM2481 is a differential bus transceiver with integrated electrical isolation introduced by ADI. It is specifically designed for bidirectional data communication over balanced multipoint bus transmission lines and complies with the ANSI EIA/TIA-485-A and ISO 8482:1987(E) standards. The device utilizes ADI’s proprietary iCoupler® magnetic isolation technology to integrate a three-channel isolator, a tri-state differential line driver, and a differential input receiver into a single package. This fundamentally replaces traditional optocoupler solutions, eliminating the inherent drawbacks of optocouplers while achieving highly reliable signal isolation.

The device’s logic side (VDD1) supports a 5 V or 3.3 V supply, while the bus side (VDD2) uses a 5 V supply. It is housed in a 16-pin wide-body SOIC package and is rated for an industrial temperature range of −40°C to +85°C.

II. ADM2481 Key Specifications

Manufacturer: Analog Devices (ADI)

Device Type: iCoupler® Isolated Half-Duplex RS-485 Transceiver

Signal Isolation Voltage: 2.5 kV rms (UL 1577 certified, 1 minute)

Maximum Data Rate: 500 kbps

Common-Mode Transient Immunity (CMTI): >25 kV/μs

Logic-Side Operating Voltage (VDD1): 3.0 V ~ 5.5 V

Bus-Side Operating Voltage (VDD2): 4.75 V ~ 5.25 V

Quiescent Current: 2.5 mA (maximum)

Number of Bus Nodes: Up to 256 transceivers

Input Impedance: 96 kΩ

Electrostatic Discharge (ESD) Protection: ±2 kV

Operating Temperature Range: −40°C to +85°C

Package: 16-pin wide-body SOIC

Safety Certifications: UL 1577, DIN EN IEC 60747-17 (VDE 0884-17)

III. Key Features and Advantages

1. iCoupler® Magnetic Isolation, Replacing Traditional Optocouplers

The ADM2481 utilizes ADI’s iCoupler® digital isolation technology, integrating a three-channel isolator with transceiver functionality onto a single chip. This completely eliminates the inherent drawbacks of optocoupler solutions, such as LED aging, limited data rates, and high power consumption. This device is UL 1577 certified (VISO = 2500 V rms, 1 minute), complies with the DIN EN IEC 60747-17 (VDE 0884-17) standard, and has a VIORM of 656 V peak, effectively breaking ground loops and withstanding high-voltage transients.

2. Ultra-Low Power Design

With a maximum quiescent current of only 2.5 mA, both the bus and logic sides operate at low power. This feature makes it ideal for power-sensitive industrial field devices and remote terminal units.

3. Slew-Rate-Limited Driver for Reduced EMI

The driver output features a limited slew rate, effectively reducing reflections caused by improperly terminated transmission lines. The controlled slew rate limits the data rate to 500 kbps, reducing electromagnetic interference (EMI) while ensuring reliable communication—which is particularly important in industrial environments where the device coexists with sensitive analog circuits.

4. True Fail-Safe Receiver Input

The receiver input features true fail-safe behavior, ensuring that the receiver output remains at a logic high level when the input is open-circuited or short-circuited. This ensures that the receiver output remains in a known state before and after communication begins, preventing data misinterpretation caused by the bus idle state.

5. High Node Count and High-Impedance Inputs

With an input impedance of 96 kΩ, the bus can accommodate up to 256 transceivers, meeting the requirements for large-scale multipoint bus networking.

6. Comprehensive Protection Mechanisms

The device integrates current-limiting protection and thermal shutdown functions to prevent excessive power consumption caused by output short circuits or bus contention, effectively enhancing system reliability. Additionally, when the driver is disabled or VDD1/VDD2 = 0 V, the device imposes minimal load on the bus.

IV. Application Areas

With core advantages such as integrated isolation, low power consumption, and high reliability, the ADM2481 is primarily used in the following scenarios:

Industrial Automation and Process Control

In industrial automation systems, the RS-485 bus is one of the most widely used physical-layer bus standards. The ADM2481’s 2.5 kV isolation capability effectively breaks ground loops, withstands transient high-voltage surges in industrial environments, and ensures reliable communication between PLCs, DCSs, and remote I/O modules.

Building Control Networks

Building automation systems (such as HVAC, security systems, and lighting control) widely adopt RS-485 as their communication bus. The ADM2481’s isolation capabilities and 500 kbps data rate meet the reliability and real-time requirements of building control networks, while its low power consumption makes it suitable for building equipment that operates continuously over long periods.

Multipoint Data Transmission Systems

The high input impedance of 96 kΩ allows up to 256 nodes to be connected on a single bus, making it ideal for multipoint data transmission systems requiring a large number of terminal devices, such as remote terminal units (RTUs) and distributed data acquisition networks.

Motor Control and Motion Control

In motor drive and motion control applications, electromagnetic interference generated by power circuits can couple into the communication bus. The ADM2481’s high common-mode transient immunity (>25 kV/μs) and slew-rate-limited drivers effectively suppress interference, ensuring accurate transmission of control commands.

Low-Power RS-485/RS-422 Networks

This device is specifically designed for low-power RS-485/RS-422 networks and isolated interfaces, making it suitable for battery-powered remote monitoring equipment, portable industrial instruments, and applications requiring electrically isolated communication interfaces.

For the latest pricing information or bulk purchases of the ADM2481, please contact Mingjiada Electronics.

Contact: Mr. Chen

Mobile: +86 13410018555

Email: sales@hkmjd.com

Homepage: https://www.integrated-ic.com/

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