company blog about Supply ADI Isolated Interface:Isolated CAN,Isolated I²C,Isolated SPI,Isolated USB

Supply ADI Isolated Interface:Isolated CAN,Isolated I²C,Isolated SPI,Isolated USB

Shenzhen Mingjiada Electronics Co., Ltd., as an authorised independent distributor of globally renowned electronic components, has established a stable product supply chain through its specialist distribution experience in the electronic components sector. We offer our customers a guarantee of genuine products, highly competitive prices and rapid delivery services.

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I. Isolated CAN: A Reliable Link for Industrial and Automotive Communication

The CAN (Controller Area Network) bus is one of the most widely used serial communication protocols in industrial automation and automotive electronics, renowned for its high reliability, multi-master communication and strong fault tolerance. However, in scenarios such as high-voltage industrial environments and automotive high-voltage systems, the common-mode voltage between CAN bus nodes can reach several hundred volts. Standard CAN transceivers are unable to withstand such interference, making them prone to communication interruptions and component damage. ADI’s isolated CAN interface products utilise magnetic isolation technology to achieve electrical isolation whilst retaining the core advantages of the CAN protocol, effectively resolving the aforementioned issues.

1. Core Technology and Product Features

ADI’s isolated CAN products primarily utilise iCoupler magnetic isolation technology. This technology enables contactless signal transmission via wafer-level transformers, replacing the light-emitting diodes and photodetectors found in traditional optocouplers, thereby avoiding the drawbacks associated with optocouplers, such as temperature drift, ageing and significant transmission delays. Taking classic products such as the ADM2483 and ADM3053 as examples, their core features are as follows:

- High isolation performance: Supports isolation voltages of up to 5 kV RMS and an isolation withstand voltage of 2,500 V RMS for 1 minute. Certified to authoritative standards such as UL 1577 and VDE 0884, these devices effectively isolate electrical interference between the high-voltage and low-voltage sides, ensuring the safety of low-voltage control circuits.

- Compatibility with CAN protocol standards: Fully compliant with the ISO 11898-2 standard, supporting both standard CAN and CAN FD (on certain products), with data transmission rates of up to 5 Mbps (CAN FD), meeting the high-speed communication requirements of industrial field and automotive systems.

- Low power consumption and wide temperature range: Operating current as low as 4.5 mA, with negligible standby power consumption, making it suitable for battery-powered applications; the operating temperature range spans -40 °C to +105 °C, with some products even supporting -40 °C to +125 °C, enabling adaptation to high-temperature industrial environments and extreme temperatures both inside and outside the vehicle cabin.

- Comprehensive protection features: Built-in protection functions include bus short-circuit protection, thermal shutdown protection and overvoltage protection. In the event of a CAN bus short-circuit or overvoltage, the device automatically enters a protective state to prevent damage; some products also feature fault diagnosis outputs, facilitating real-time monitoring of the communication status by the system.

2. Typical Application Scenarios

Isolated CAN is one of the most widely used products within ADI’s range of isolation interfaces. Key application scenarios include: communication link isolation for equipment such as PLCs, variable frequency drives, servo motors and industrial robots in the industrial automation sector; communication isolation between on-board high-voltage BMS (battery management systems), motor controllers, on-board chargers (OBCs) and vehicle control units (VCUs) in the automotive electronics sector; signal transmission isolation for equipment such as distribution network automation terminals, charging points and photovoltaic inverters in the power and energy sector; furthermore, isolated CAN plays a crucial role in applications such as lift control, rail transport and marine electronics, ensuring stable system operation in complex electromagnetic environments.

II. Isolated I²C: An Isolation Solution for Low-Speed, Short-Range Communication

I²C (Inter-Integrated Circuit) is a two-wire serial communication bus characterised by a small number of pins, simple wiring and support for multiple master devices. It is widely used for short-range communication between peripherals—such as sensors, memory devices and displays—and the main control chip. However, in industrial environments and medical equipment, common-mode voltage interference may exist between the main control unit and peripherals, causing issues such as data packet loss and communication failures in standard I²C interfaces. ADI’s isolated I²C interface products provide a secure solution for low-speed, short-range communication by integrating isolation functionality.

1. Core Technology and Product Features

ADI’s isolated I²C products are also based on iCoupler magnetic isolation technology; some products further integrate an isoPower isolated power supply, achieving an integrated design for both signal and power isolation, thereby simplifying the peripheral circuitry. Taking products such as the ADUM1250 and ADUM3250 as examples, their core features are as follows:

- Bidirectional isolated communication: Supports bidirectional isolation of both the SDA (serial data) and SCL (serial clock) lines on the I²C bus. Fully compatible with the I²C standard protocol, supporting standard mode (100 kbps), fast mode (400 kbps) and high-speed mode (3.4 Mbps) to accommodate different data rate requirements.

- Advantages of integrated isolated power supplies: Certain models incorporate an isoPower isolated DC-DC converter, capable of providing an isolated power output of up to 500 mW. This eliminates the need for additional isolated power supply circuitry, significantly simplifying system design whilst reducing PCB footprint and costs.

- High immunity to interference: Magnetic isolation technology provides excellent electromagnetic interference (EMI) and electromagnetic compatibility (EMC) performance, enabling the device to withstand pulse noise and surge interference in industrial environments and ensuring the accuracy of data transmission; The isolation voltage supports 2500 VRMS, meeting the safety isolation requirements for medical and industrial applications.

- Compact packaging: Utilising compact packages such as SOIC and MSOP, these devices occupy minimal PCB space and are well-suited to the design requirements of portable devices and compact industrial modules; they also feature low power consumption, with quiescent current as low as the microampere range, making them ideal for battery-powered portable medical devices and IoT terminals.

2. Typical Application Scenarios

Isolated I²C is primarily used in low-speed, short-range communication scenarios where isolation is required: in the medical equipment sector, for devices such as patient monitors, blood glucose metres and electrocardiographs, to provide isolated communication between sensors and the main control unit, thereby preventing high-voltage signals from causing harm to patients; in the industrial sector, for internal communication isolation in devices such as industrial sensors (temperature, pressure and humidity sensors), PLC expansion modules and industrial instruments; in the consumer electronics sector, such as smart home devices and wearables, to provide isolation between peripherals and the main control chip, thereby enhancing device safety and resistance to interference; furthermore, in automotive electronics applications—including in-vehicle sensors and instrument clusters—isolated I²C can also be used to enable safe communication between high- and low-voltage sides.

III. Isolated SPI: The Isolation Solution for High-Speed Serial Communication

SPI (Serial Peripheral Interface) is a high-speed synchronous serial communication interface characterised by high data rates, a simple protocol and support for full-duplex communication. It is widely used for communication between high-speed peripherals—such as ADCs, DACs, memory and display controllers—and the main control chip. In applications such as industrial control and power electronics, high-speed SPI communication faces more severe electromagnetic interference, and there is an urgent need for electrical isolation between high- and low-voltage sides. ADI’s isolated SPI interface products, with their high data rates and excellent isolation performance, are the ideal choice for isolating high-speed serial communication.

1. Core Technology and Product Features

ADI’s isolated SPI products are based on iCoupler magnetic isolation technology. To address the multi-wire nature of the SPI interface (typically comprising four lines: SCK, MOSI, MISO and CS), they employ a multi-channel isolation design to achieve isolation across all signal channels. Taking products such as the ADUM1401 and ADUM3401 as examples, their core features are as follows:

- High-speed communication capability: Supports data transfer rates of up to 50 Mbps, with some products even supporting 100 Mbps, meeting the communication requirements of high-speed peripherals such as ADCs, DACs and high-speed memory; supports full-duplex communication to ensure efficient data transfer.

- Multi-channel isolation design: Provides 4-channel isolation (with some products supporting 2 or 6 channels), allowing flexible adaptation to the isolation requirements of the SPI interface’s four-wire configuration (SCK, MOSI, MISO, CS); some products also support flexible channel configuration to accommodate the communication protocols of different peripherals.

- High reliability and stability: Magnetic isolation technology eliminates the issue of optical component ageing; transmission latency is low and stable, with a maximum latency of just a few nanoseconds, thereby preventing communication synchronisation issues caused by excessive latency; isolation voltage supports 2500 VRMS and has passed authoritative certifications such as UL and VDE, ensuring electrical safety on both the high- and low-voltage sides.

- Wide Power Supply Voltage Range: Supports multiple power supply voltages, including 3.3V and 5V, to meet the power requirements of various master chips and peripherals; built-in level conversion functionality enables signal isolation and level conversion between different voltage domains, simplifying system design.

2. Typical Application Scenarios

Isolated SPI is primarily used in high-speed serial communication scenarios where both isolation and data rate are critical: high-speed data acquisition systems in the industrial control sector (isolated communication between ADCs and main control chips), high-speed PLC modules, and joint control modules for industrial robots; in the power and energy sector, it provides communication isolation between high-speed power devices and control units in photovoltaic inverters, wind power converters and energy storage systems; in the automotive electronics sector, for isolated communication between high-speed peripherals and the main control chip in on-board cameras, in-car entertainment systems and Advanced Driver Assistance Systems (ADAS); furthermore, in high-speed data acquisition modules for medical equipment and electronic devices in the aerospace sector, isolated SPI can also be used to achieve high-speed, secure serial communication.

IV. Isolated USB: An Isolated Upgrade for Universal Serial Communication

USB (Universal Serial Bus) is currently the most widely used general-purpose serial communication interface, supporting plug-and-play and high-speed data transfer, and is extensively utilised in computers, industrial equipment, medical devices and consumer electronics. However, in industrial environments and medical devices, the need for electrical isolation of USB interfaces is becoming increasingly urgent. For example, when medical devices are connected to computers, high-voltage signals must be isolated to ensure patient safety; when industrial equipment communicates with a host computer via USB, field interference must be isolated to ensure data stability. ADI’s isolated USB interface products provide a safe and reliable solution for USB communication by integrating isolation functionality.

1. Core Technologies and Product Features

ADI’s isolated USB products are based on iCoupler magnetic isolation technology and isoPower integrated isolation power supply technology, achieving full isolation of USB signals whilst remaining compatible with USB standard protocols. Taking products such as the ADUM4160 and ADUM3160 as examples, their core features are as follows:

- Compatibility with USB standard protocols: Fully compatible with the USB 2.0 standard, supporting low-speed (1.5 Mbps) and full-speed (12 Mbps) data transmission; some products support high-speed (480 Mbps) transmission. They can directly replace standard USB interfaces without the need to modify existing communication protocols or software.

- Integrated isolation design: Incorporates iCoupler magnetic isolation technology and isoPower isolated power supply to achieve dual isolation of USB signals (D+, D-) and the power supply, eliminating the need for additional isolation power supply circuitry and simplifying system integration; the isolation voltage supports 2500 VRMS, meeting safety isolation requirements for medical and industrial applications.

- Comprehensive protection features: Built-in short-circuit protection for the D+ and D- lines provides defence against electrostatic discharge (ESD) interference at the USB interface; ESD performance complies with the ANSI/ESD STM5.1-2007 standard, enhancing the interface’s durability and reliability; certain products also feature thermal shutdown protection to prevent damage caused by overheating.

- Wide temperature range and low power consumption: The operating temperature range spans from -40°C to +105°C, making it suitable for extreme temperature environments in industrial and automotive applications; the low-power design, with low standby current, is ideal for portable devices and battery-powered scenarios; the compact packaging meets the design requirements of miniaturised devices.

2. Typical Application Scenarios

Isolated USB is primarily used in scenarios requiring USB communication where isolation is essential: in the medical equipment sector, communication isolation between patient monitors, ultrasound equipment, diagnostic instruments and computers ensures the safety of patients and operators; in the industrial sector, for communication isolation during the commissioning of industrial equipment, data acquisition, and between PLCs and host computers, to prevent interference from industrial environments from affecting data transmission; in the automotive electronics sector, for communication isolation between On-Board Diagnostics (OBD) systems, in-vehicle entertainment systems and external devices; furthermore, in consumer electronics—including smart home devices and wearables—as well as in the aerospace and rail transport sectors, isolated USB can also be used to achieve secure and reliable universal serial communication.