2 Automotive Audio Bus A B Transceiver AD2426W/AD2427W/AD2428W Data Sheet 2 2 A B BUS FEATURES A B TRANSCEIVER FEATURES 2 Line topology Configurable as A B bus master or slave (AD2428W) 2 Single master, multiple slave I C interface 2 Up to 15 m between nodes and up to 40 m overall cable 8-bit to 32-bit multichannel I S/TDM interface 2 length I S/TDM/PDM programmable data rate Communication over distance Up to 32 upstream and 32 downstream channels Synchronous data PDM inputs for 4 high dynamic range microphones on mas- 2 2 Multichannel I S/TDM to I S/TDM ters or slaves 2 Clock synchronous, phase aligned in all nodes Support for receiving I S data on nodes with up to 4 PDM microphones Low latency slave to slave communication 2 2 Unique ID register for each transceiver Control and status information I C to I C Support for crossover or straight-through cabling GPIO over distance Programmable settings to optimize EMC performance Bus power or local power slave nodes Configurable with SigmaStudio graphical software tool APPLICATIONS Qualified for automotive applications Automotive audio communication link Active noise cancellation Microphone arrays for hands free and in car communication IOVDD DVDD PLLVDD VOUT1 VIN VOUT2 ATRXVDD/BTRXVDD 2 SCL A B BP PLL VREG1 VREG2 SDA TRX B BCM (Towards IRQ/IO0 2 I C BN Last Slave) ADR1/IO1/CLKOUT1 SWP ADR2/IO2/CLKOUT2 DIAGNOSTICS SENSE BCLK/PDMCLK 2 AP A B SYNC 2 I S/TDM ACM TRX A DTX0/DTX1 PDM (Towards AN Master) DRX0/DRX1 IO7 VSS VSSN Figure 1. Functional Block Diagram 2 2 A B and the A B logo are registered trademarks of Analog Devices, Inc. Rev. Sp0 Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106 U.S.A. Specifications subject to change without notice. No license is granted by implication Tel: 781.329.4700 2018 Analog Devices, Inc. All rights reserved. or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.comData Sheet AD2426W/AD2427W/AD2428W GENERAL DESCRIPTION 2 2 The Automotive Audio Bus (A B ) provides a multichannel, Finally, the transceiver also supports an A B bus powering fea- 2 I S/TDM link over distances of up to 15 m between nodes. It ture, where the master node supplies voltage and current to the embeds bidirectional synchronous pulse-code modulation slave nodes over the same daisy-chained, twisted pair wire cable (PCM) data (for example, digital audio), clock, and synchroni- as used for the communication link. 2 zation signals onto a single differential wire pair. A B supports a 2 Complete technical specifications are available for the A B direct point to point connection and allows multiple, daisy- transceiver. Contact your nearest Analog Devices sales office to chained nodes at different locations to contribute and/or con- complete the nondisclosure agreement (NDA) required to sume time division multiplexed channel content. receive additional product information. 2 A B is a single-master, multiple-slave system where the trans- Table 1. Product Comparison Guide ceiver chip at the host controller is the master. The master generates clock, synchronization, and framing for all slave Feature AD2426W AD2427W AD2428W 2 nodes. The master A B chip is programmable over a control bus 2 Master capable No No Yes (I C) for configuration and read back. An extension of this con- 2 Functional TRX blocks A only A + B A + B trol bus is embedded in the A B data stream, which grants direct 2 access of registers and status information on slave transceivers I S/TDM support No No Yes 2 2 as well as I C to I C communication over distance. PDM microphone inputs 4 mics 4 mics 4 mics The transceiver can connect directly to general-purpose digital Max node to node cable length 15 m 15 m 15 m 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 2 I S/TDM interface. It also provides a PDM interface for direct connection of up to four PDM digital microphones. 2 I C refers to a communications protocol originally developed by Philips Semiconductors (now NXP Semiconductors). 2018 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D16813F-0-5/18(Sp0) Rev. Sp0 Page 2 of 2 May 2018