The ADAU1442, ADAU1445, and ADAU1446, referred to collectively as the ADAU144x, are enhanced audio processors that allow full flexibility in routing all input and output signals. The SigmaDSP® core features full 28-bit processing (56-bit in double precision mode), synchronous parameter loading for ensuring filter stability, and 100% code efficiency with the SigmaStudio™ tools. This DSP allows system designers to compensate for the real-world limitations of speakers, amplifiers, and listening environments, resulting in a dramatic improvement of the perceived audio quality through speaker equalization, multiband compression, limiting, and third-party branded algorithms.

The flexible audio routing matrix (FARM) allows the user to multiplex inputs from multiple sources running at various sample rates to or from the SigmaDSP core. This drastically reduces the complexity of signal routing and clocking issues in the audio system. FARM includes up to eight stereo asynchronous sample rate converters (depending on the device model), Sony/ Philips Digital Interconnect Format (S/PDIF) input and output, and serial (I2S) and time division multiplexing (TDM) I/Os. Any of these inputs can be routed to the SigmaDSP core or to any of the asynchronous sample rate converters (ASRCs). Similarly, any one of the output signals can be taken from the SigmaDSP core or from any of the ASRC outputs. This routing scheme, which can be modified at any time via control registers, allows for maximum system flexibility.

The ADAU1442, ADAU1445, and ADAU1446 differ only in ASRC functionality and packaging. The ADAU1442 and ADAU1445 contain 16 channels of ASRCs and are packaged in a TQFP, whereas the ADAU1446 contains no ASRCs and is packaged in an LQFP.

The ADAU144x can be controlled in one of two operational modes. First, the settings of the chip can be loaded and dynamically updated through the SPI/I2C port. Second, the DSP can self-boot from an external EEPROM in a system with no microcontroller. There is also a bank of multipurpose (MP) pins that can be used as general-purpose digital I/Os or as inputs to the 4-channel auxiliary control ADC.

The ADAU144x is supported by the SigmaStudio graphical development environment. This software includes audio processing blocks such as FIR and IIR filters, dynamics processors, mixers, low level DSP functions, and third-party algorithms for fast development of custom signal flows.

Applications

• Automotive audio processing
  Head units
  Navigation systems
  Rear seat entertainment systems
  DSP amplifiers (sound system amplifiers)
• Commercial audio processing

Data Sheet, Rev. PrA, 10/08