- ADI’s ADuM1250W hot-swappable, I²C iCoupler® digital isolators directly isolate bi-directional data eliminating the need to split transmit and receive signals into separate channels and reducing component count in electric and hybrid-electric vehicles.

Norwood, MA (08/24/2010) - Analog Devices, Inc. (ADI), a global leader in high-performance semiconductors for signal processing applications, is introducing the industry’s first automotive grade products to provide true bidirectional isolation for the lower cost I2C serial bus. Based on ADI’s proprietary iCoupler® digital isolation technology , the ADuM1250W hot swappable, dual I2C digital isolator reduces board space by as much as 80 percent and greatly reduces the system cost associated with isolating I2C buses. This is accomplished by eliminating optocouplers and support circuitry previously required in isolated I2C interfaces. The ADuM1250W is the industry’s first I2C digital isolator to carry an AEC-Q100 qualified1 –40°C to +125°C automotive temperature rating and is based on the award winning ADuM125x family of I2C isolators that have been in volume production for over three years in a wide range of industrial, instrumentation, networking and other applications.

The I2C bus is a cost-effective, two wire interface between controllers and peripheral devices such as data converters, memory products, switches, sensors and power supply ICs. The bus uses bidirectional lines to transmit and receive signals over the same wire, allowing two-wire signaling of clock and data. This reduces complexity and cost by eliminating extra wiring and components. In a variety of HEV and automotive applications, controllers or peripherals are isolated from the bus to avoid interference or harmful voltage levels. Typically, isolation has been achieved with optocouplers, but doing so increases the cost and complexity of the I2C interface because unidirectional optocouplers must be accommodated by separating each of the two bidirectional I2C channels into two unidirectional channels. The resultant four unidirectional channels are then each isolated with an optocoupler and recombined into two bidirectional channels. The additional circuitry associated with the bidirectional/unidirectional conversions and the isolation of the four unidirectional channels adds complexity and cost that offset the intended benefits of the I2C bus. With the ADuM1250W isolator, this complexity and cost is avoided as a single component directly provides bidirectional isolation to both of the I2C lines. This small, complete isolation device ensures the signal integrity of the bidirectional I2C bus while reducing component count, cost, board space, and complexity. To download the data sheet, visit:

ADuM1250W iCoupler® Digital Isolator Key Features and Benefits

  • AEC-Q100 qualified, 125˚C operation, supports the quality and reliability requirements of automotive applications
  • Small surface mount 8-lead SOIC package saves up to 80% board space
  • True bi-directional isolated data paths eliminate the need for buffers and other external components
  • Industry standard I2C interface ensures reliable operation with I2C compliant peripherals
  • 1MHz operation provides ample bandwidth to operate with high performance peripherals and devices
  • 3.0- to 5.5-V supply/logic levels enables flexible operation and level shifting

Pricing and Availability

Product Sample Availability Price in 10,000s Packaging
ADuM1250W NOW $2.21 8-lead SOIC_narrow

For more information on ADI’s I2C isolators, visit: . For more information on ADI’s broad portfolio of automotive products, visit: For more information on ADI’s digital isolation products, visit: . To connect with a specialist, cross reference tools, and more resources on how to use and obtain ADI products, please click here: .

iCoupler® Digital Isolation Technology

With more than 350 million channels deployed, ADI’s proven iCoupler technology is based on chip-scale transformers, rather than on the LEDs and photodiodes found in optocouplers. Transformers support higher data rates, consume less power, and are more stable over life as compared to LEDs and photodiodes. By fabricating the transformers directly on-chip using wafer-level processing, iCoupler channels can be integrated with each other and other semiconductor functions at low cost. iCoupler transformers are planar structures formed from CMOS and gold metal layers. A high breakdown polyimide layer underneath the gold layer insulates the top transformer coil from the bottom. CMOS circuits connected to the top coil and bottom coil provide the interface between each transformer and its external signals. ADI provides a variety of automotive qualified isolation solutions all of which can be found on their automotive web page:

About Analog Devices

Innovation, performance, and excellence are the cultural pillars on which Analog Devices has built one of the longest standing, highest growth companies within the technology sector. Acknowledged industry-wide as the world leader in data conversion and signal conditioning technology, Analog Devices serves over 100,000 customers, representing virtually all types of electronic equipment. Analog Devices is headquartered in Norwood, Massachusetts, with design and manufacturing facilities throughout the world. Analog Devices is included in the S&P 500 Index.

1: The AEC-Q100 is defined by the Automotive Electronics Council as a “Stress Test for Qualification for Integrated Circuits.”

iCoupler is a registered trademark of Analog Devices, Inc.

Editor's Contact Information:

Howard Wisniowski

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