Analog Devices Inc. AD242x Automotive Audio Bus A2B® Transceivers

Analog Devices Inc. AD242x Automotive Audio Bus (A2B®) Transceivers deliver unprecedented capability to tailor system-level performance to even the most stringent electromagnetic compatibility (EMC) requirements. The AD242x A2B Transceivers offers configurable transmit power levels, enabling developers to match system performance to specific OEM EMC requirements. The transceivers also allow expanded use cases for microphone connectivity and significantly reduce cabling complexity by distributing audio and control data plus clock and power over a single, unshielded twisted-pair wire. These features drastically lower system cost and are ideal for emerging multi-mic applications such as road noise cancellation, in-car communications, and autonomous driving. 

The AD242x A2B Transceivers are available in a 32-lead LFCSP (5mm x 5mm) package, and are fully pin-compatible, simplifying upgrade and speeding time to market. These devices are also fully compliant with all relevant automotive EMC, EMI, and ESD requirements, are fully AEC-Q100 qualified, and operate over the extended automotive temperature range (-40℃ to +105℃).

Automotive Audio Bus (A2B)

The Automotive Audio Bus (A2B) is an innovative and application-tuned technology that reduces the weight of cable harnesses by up to 75% while delivering high fidelity digital audio. A2B is optimized for audio applications delivering superior audio quality relative to analog connectivity at significantly lower total system cost than existing digital bus standards. In its simplest form, A2B is a high bandwidth (50Mbps) digital bus capable of transporting I2S audio and I2C control data together with clock and power using a single, 2-wire, unshielded, twisted pair cable over significant distances, up to 15m between nodes and 40m over the entire daisy chain.


  • A2B Bus Features
    • Line topology
      • Single master, multiple slave
      • Up to 15m between nodes and up to 40m overall cable length
    • Communication over distance
      • Synchronous data
        • Multichannel I2S/TDM to I2S/TDM
        • Synchronous clock, phase aligned in all nodes
        • Low latency slave to slave communication
      • Control and status information I2C to I2C
      • GPIO and interrupt
    • Bus power or local power slave nodes
    • Configurable with SigmaStudio graphical software tool
    • AEC-Q100 qualified for automotive applications
  • A2B Transceiver Features
    • Configurable A2B bus master or slave operation
    • I2C interface
    • 8-bit to 32-bit multi-channel I2S/TDM interface
      • Programmable I2S/TDM data rate
      • Up to 32 upstream and 32 downstream channels
    • PDM interface
      • Programmable PDM clock rate
      • Up to 4 high dynamic range microphone inputs
    • Simultaneous reception of I2S data with up to 4 PDM microphones
    • Unique ID register for each transceiver
    • Support for crossover or straight-through cabling
    • Programmable settings to optimize EMC performance


  • Autonomous Transportation
  • Advanced Driver-Assistance Systems (ADAS)
  • Vehicle Electrification
  • Cabin Electronics and Infotainment
  • Active Noise Cancellation
  • Audio Connectivity
  • Head Units and Cluster
  • Premium Audio and Amplifiers
  • Telematics
  • Video Connectivity

Additional Resources

Superior Performance in Emerging Automotive Applications

This article about Automotive Audio Bus® (A2B®) technology explains recent advances in digital microphone and connectivity technologies that enabling game-changing applications for future generations of vehicle infotainment systems.

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Using A2B for Audio-Conferencing Systems

Although A2B transceiver technology was mainly designed to solve the problem of bulky audio cabling in automotive applications, it is certainly a much more generic audio transport method with a potential widespread of applications. One such potential application for A2B technology outside of automotive space is in huddle room conferencing systems.

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Comparison Chart

Chart - Analog Devices Inc. AD242x Automotive Audio Bus A2B® Transceivers


Block Diagram

Block Diagram - Analog Devices Inc. AD242x Automotive Audio Bus A2B® Transceivers
Published: 2019-11-12 | Updated: 2023-01-24