EVAL BOARD FOR AD2428

An Automotive Audio Bus (A²B^®) system consists of a single main node and at least one subordinate node, where the transceiver at the host controller is the main node. The main transceiver generates clock, synchronization, and framing for all subordinate nodes and is programmable over a control bus (I²C) for configuration and readback. An extension of this control bus is embedded in the A²B data stream, which enables the host to directly access subordinate transceiver registers and any I²C-connected peripherals on subordinate nodes. Transceivers can connect directly to PDM microphones and to numerous peripherals via I²C and a multichannel I²S/TDM interface. 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, thus eliminating the need for a power supply on bus-powered subordinate nodes. Due to the numerous configurations that are possible for a given A²B system, there are several evaluation platforms that can be used in combination to verify system operation, as summarized in the table below.

• AD2428W Automotive Audio Bus A²B^® Transceiver
  • Programmable as A²B main or subordinate
  • Multichannel I²S/TDM interface
  • Three PDM microphone inputs
  • Locally powered
    • LT8609 – 2A/3A Peak Synchronous Step-Down Regulator with 2.5μA Quiescent Current
    • LTC4040 – 2.5A Battery Backup Power Manager
    • LTC3621 – 1A Synchronous Step-Down Regulator
    • LTC3121 – 1.5A Synchronous Step-Up DC/DC Converter
  • Configurable with SigmaStudio^™ graphical software tool
• ADAU1452 SigmaDSP^® Digital Audio Processor
• ADAU1761 SigmaDSP Stereo, Low Power, 96kHz, 24-Bit Audio Codec with Integrated PLL
• Reset, Status, and Interrupt LEDs
• Jumper Controls
  • Power, clock, and synchronization signal source
  • Data routing