A2B is a high bandwidth, bidirectional, digital audio bus. A2B is capable of transporting I2S/TDM/PDM data and I2C control information, along with clock and power, using a single, 2-wire UTP cable over distances up to 15 m between nodes and 40 m over the entire daisy chain. A2B can be used as its own network with embedded sub-networks, or as an endpoint transport bus used in combination with other, longer distance protocols. The clock is synchronous on all nodes in a single A2B network. Microphone and serial audio data is received on each node in the system simultaneously.

Advantages of A2B Audio Bus

Configurable, Flexible, Low Risk and Easy to Use

A2B transceivers allow an I2C host to access all transceivers in a system. Designing an A2B enabled system is simplified using the SigmaStudio® graphical design environment—the same development tool that supports the Analog Devices SigmaDSP® and SHARC® processor families. A broad array of full-featured evaluation systems is available to quickly prototype an A2B network and facilitate early system proof of concept, test, verification, and debug.

Reduced System & Cable Costs, Weight, & Complexity

A2B eliminates the need for an expensive microcontroller and external memory. The transceiver’s ability to provide power to remote nodes over the same UTP (Unshielded Twisted Pair) cable used to transport data removes the need for a local power supply on each bus-powered slave node, reducing the overall system BOM costs. The UTP cable provides system-level cost savings when compared to other digital bus architectures that may require two or three twisted-pair connections or a costly cabling scheme, such as the heavy cable harnesses required to connect audio systems in vehicles.

Superior Audio Quality

With a configurable 44.1 kHz or 48 kHz frame rate and up to a 50 Mbps bandwidth, A2B is ideal for transporting digital audio and delivers superior audio quality relative to analog connections. System nodes support up to 32 bus slots in each direction, and the slot widths are programmable up to 32-bit, thereby supporting I2S and numerous TDM configurations up to TDM32. PDM input is also natively supported, with the transceiver decimating the input to PCM format before placing it on the A2B bus.

Deterministic Low Latency

A2B technology ensures simultaneous sampling and delivery of data on all system nodes for each frame. The frame structure is fully managed at the master node to program each transceiver’s use of the available data slots in both directions, whether to contribute, extract, or read and pass data on to the next node in the line topology. Delays due to bus collisions or the reassembly of packetized data are removed. A2B features deterministic and very low, sub 50 μs latency.

Horizontal Rule

A2B Solves Automotive and Other Audio Market Challenges

Automotive & Transportation

Automotive and Transportation

  • Audio ECU
  • Active noise cancellation
  • Road noise cancellation
  • Personal audio zones/active speakers
  • eCall and telematics systems
  • Autonomous driving systems
  • Smart radio connectivity

See Audio Connectivity Solutions.

Building Technology

Building Technology
(Smart Buildings)

  • Microphone arrays for hands-free/speech recognition
  • A/V conference rooms
  • Residential intercom systems


  • ProAV
  • Vital signs monitoring (wearables)
  • Home theater

A better design experience.
A more dynamic automotive experience.
ADI's A2B technology delivers both.

Less complex, less expensive, and lighter. A2B simplifies and solves your audio design challenges.

Learn more about A2B in automotive applications

A2B Technology




This master-capable transceiver features an I2S/TDM interface to provide the clock/sync signals for an A2B system consisting of up to 10 slave devices. This device can also be configured as a slave to support slave nodes requiring an I2S/TDM interface.



Featuring A- and B-side LVDS transceivers, this midline microphone slave node device (no I2S/TDM interface) supports up to 32 bus slots in each direction.

A2B Products



The EVAL-AD2428WD1BZ A2B evaluation board provides PDM microphone inputs, as well as a serial I2S/TDM interface, to support master or slave node functionality in an A2B system. The board also provides flexibility to use either local or A2B bus power, allowing any supported transceiver configuration to be evaluated.

EVAL-AD2428WD1BZ Details


A2B Evaluation Boards


Signal Chains


Click on a part in the diagram below

A2B Partners

Audio Precision | APx B Series Audio Analyzers


Audio Precision By combining the capabilities of Audio Precision’s APx500 audio analyzers and software, and Mentor’s A2B Analyzer System, software and ASIO driver, developers can easily create a complete, closed-loop multichannel A2B audio test system.

The APx audio analyzer, along with the Mentor analyzer platform, delivers comprehensive, multichannel audio measurement analysis and offers a wide range of interface options, including analog, Bluetooth®, digital serial (TDM) and PDM. Working as a complete system, these tools eliminate the effort required to develop, and support, in-house, custom test solutions.

For more information please visit Audio Precision.

Clockworks Signal Processing | A2B – I2S Module/Module EVM System


Clockworks Signal Processing Clockworks’ A2B module offers developers a simple way to develop A2B products by creating prototypes based on the A2B module connected to EVM board(s) for the desired peripheral functions. Typically, Clockworks’ A2B module is used with ADC or DAC boards, but can also be used with Class D amplifier devices with direct I2S input, or digital microphones with I2S output.

For more information please visit partnerzone clockworks.

DE Design Works | A2B Industrial Design Services


DE Design Works A2B does not have to stop at the automobile industry. The daisy chain system can be implemented into many other products to improve efficiency and lessen cost. DE Design Works is working to make the technology available across all industries.

DE Design Works deep breadth of product design experience, quick-to-market prototyping, proven turnkey design methods, testing capabilities, quality management, and production support offer a suite of value services in product development ending with the right product designed for the market at the fastest possible rate.

For more information please visit dedesignworks.

Mentor Automotive | A2B Analyzer System


Mentor Automotive | A2B Analyzer System The A2B Analyzer System is designed for development teams servicing automotive OEMs, Tier 1s, and audio connectivity equipment suppliers. The deterministic nature of the A2B technology makes it particularly well-suited for automotive audio devices (active speakers, microphones) and newer applications, such as active noise cancellation (ANC), in-car communications, and so on.

For more information please visit A2B Analyzer System.

Mentor Automotive | A2B Bus Monitor System


Mentor Automotive | A2B Bus Monitor System The A2B Bus Monitor System is a powerful debug tool that provides unprecedented insights into the network traffic on an A2B technology based audio network. The A2B Bus Monitor System is a combination of a compact, professional grade, single-unit hardware device, and an easy to use host application software.

For more information please visit A2B Bus Monitor System.

NOFFZ Technologies | ITD 1024 A2B Component Tester


Noffz Technologies ITD 1024 is an off-the-shelf solution for A2B®, an emerging automotive audio bus. In combination with a comprehensive set of software tools, ITD 1024 allows rapid testing of various A2B® components, such as audio speakers, amplifiers, microphone arrays, sensors, and actuators.

For more information please visit ITD 1024.

Total Phase | A2B Bus Monitor (Promira) and A2B Bus Monitor Level 1 Application Software


Total Phase With an A2B Bus monitor attached and non-intrusively sniffing an A2B bus, A2B superframes are decoded and disassembled into I2S/TDM audio data and control data for easy debugging. Additionally, full reporting on interrupts and GPIO handshakes are correlated into the data capture.

For more information please visit Total Phase.