Overview
Features and Benefits
A2B BUS FEATURES
- Line topology
- Single main node, multiple subordinate nodes
- Up to 15 m between nodes and up to 40 m overall cable length
- Communication over distance
- Synchronous data
- Multichannel I2S/TDM to I2S/TDM
- Synchronous clock, phase aligned in all nodes
- Low latency node to node communication
- Control and status information I2C to I2C
- GPIO and interrupt
- Synchronous data
- Bus power or local power subordinate nodes
- Configurable with SigmaStudio/SigmaStudio+ graphical software tool
- AEC-Q100 qualified for automotive applications
A2B TRANSCEIVER FEATURES
- Configurable A2B bus main node or subordinate node
- Programmable via I2C interface
- 8-bit to 32-bit multichannel 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
- Crossover or straight-through cabling
- Programmable settings to optimize EMC performance
Product Details
The Automotive Audio Bus (A2B®) provides a multichannel, I2S/TDM link over distances of up to 15 m between nodes. It embeds bidirectional synchronous pulse-code modulation (PCM) data (for example, digital audio), clock, and synchronization signals onto a single differential wire pair. A2B supports a direct point to point connection and allows multiple, daisy-chained nodes at different locations to contribute and/or consume time division multiplexed (TDM) channel content.
A2B is a single main node, multiple subordinate node system where the transceiver at the host controller is the main node. The main node generates clock, synchronization, and framing for all subordinate nodes. The main A2B transceiver is programmable over a control port (I2C) for configuration and read back. An extension of the control port protocol is embedded in the A2B data stream, which allows direct access of registers and status information on subordinate transceivers, as well as I2C to I2C communication over distance.
The transceiver can connect directly to general-purpose digital signal processors (DSPs), field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), microphones, analog-to-digital converters (ADCs), digital-to-analog converters (DACs), and codecs through a multichannel I2S/TDM interface. It also provides a pulse density modulation (PDM) interface for direct connection of up to four PDM digital microphones.
Finally, the transceiver also supports an A2B bus powering feature, where the main node supplies voltage and current to the subordinate nodes over the same daisy-chained, twisted pair wire cable as used for the communication link.
| Feature | AD2420 | AD2426 | AD2427 | AD2428 | AD2429 |
| Main node capable | No | No | No | Yes | Yes |
| Number of subordinate nodes discoverable1 | N/A | N/A | N/A | Up to 10 | Up to 2 |
| Functional TRX blocks | A only | A only | A + B | A + B | B only |
| I2S/TDM support | No | No | No | Yes | Yes |
| PDM microphone inputs | 2 mics2 | 4 mics | 4 mics | 4 mics | 4 mics |
| Max node to node cable length | 5 m | 15 m | 15 m | 15 m | 5 m |
1 N/A means not applicable.
2 PDM microphones must be connected to the DRX0/IO5 pin.
Applications
- Audio communication link
- Microphone arrays
- Beamforming
- Hands free and in car communication
- Active and road noise cancellation
- Audio/video conferencing systems
Product Categories
Markets and Technologies
Please contact your local ADI sales office or authorized ADI product distributor to receive additional product information and technical support.
Product Lifecycle
Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (7)
Documentation & Resources
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AD242x Automotive Audio Bus A2B Transceiver Data Sheet (Rev. D)6/1/2022PDF1 M
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AD242x/242xW Technical Reference Manual (Rev. 1.1)10/17/2019PDF2 M
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EVAL-AD2428WD1BZ User Guide (Rev. 1.1)10/16/2019PDF661 K
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EE-421: EVAL-AD2428WG1BZ Evaluation Board User Guide (Rev. 1)10/16/2019PDF373 K
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EE-420: EVAL-AD2428WC1BZ Evaluation Board User Guide (Rev. 1)10/16/2019PDF287 K
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EE-419: EVAL-AD2428WB1BZ Evaluation Board User Guide (Rev. 1)10/16/2019PDF499 K
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A2B Class-D Amplifier Module User Guide7/10/2019WIKI
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AD2426/AD2427/AD2428 Silicon-Anomalies (Rev. C)3/31/2020PDF165 K
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AD242x(W) Enhanced Automotive Audio Bus Transceivers10/12/2018PDF903 K
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Analog Devices Enhanced A2B Transceivers Deliver Unparalleled Flexibility for Emerging Applications4/21/2022
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Analog Devices’ Expanded Series of A2B Transceivers Significantly Improves Bus-bandwidth Utilization4/21/2022
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Ford Motor Company Selects Analog Devices’ Automotive Audio Bus™ for its Next-Generation Infotainment Systems4/21/2022
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How A2B Technology and Digital Microphones Enable Superior Performance in Emerging Automotive Applications5/3/2021 Analog Dialogue
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The A to Z of A2B Applications9/1/2020 Analog Dialogue
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Sensor, Power Management, and Bus Solutions as Drivers of Global Megatrends2/1/2019
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Innovative Digital Bus Architecture Reduces Audio System Costs10/1/2015
Software & Systems Requirements
Software Development Tools
A2B® Software
A2B network design tool and embedded software stack that allows audio network designers to graphically design an A2B network and deploy it into an embedded platform.
SigmaStudio®+
System level solution for Automotive Audio, Connectivity and Algorithm/IP applications
SigmaStudio®
Graphical development tool for programming, development, and tuning software for ADI DSP audio processors and A2B® transceivers.
Design Resources
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
PCN-PDN Information
Support & Discussions
AD2428 Discussions
I2C Master / Slave Configuration
7 week(s) ago in A2B
RE: Mixed Nodes AD2428(Manin Node) and AD2433(Sub Node)
10 week(s) ago in A2B
Sample & Buy
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Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.