ADAU1702:  SigmaDSP® 28-/56-Bit Audio Processor with Two ADCs and Four DACs

The ADAU1702 is a complete single-chip audio system with a 28-/56-bit audio DSP, ADCs, DACs, and microcontroller-like control interfaces. Signal processing includes equalization, cross-over, bass enhancement, multiband dynamics processing, delay compensation, speaker compensation, and stereo image widening. This processing can be used to compensate for real-world limitations of speakers, amplifiers, and listening environments, providing dramatic improvements in perceived audio quality.

Its signal processing is comparable to that found in high end studio equipment. Most processing is done in full 56-bit, double precision mode, resulting in very good low level signal perfor-mance. The ADAU1702 is a fully programmable DSP. The easy to use SigmaStudio™ software allows the user to graphically configure a custom signal processing flow using blocks such as biquad filters, dynamics processors, level controls, and GPIO interface controls.

ADAU1702 programs can be loaded on power-up either from a serial EEPROM through its own self-boot mechanism or from an external microcontroller. On power-down, the current state of the parameters can be written back to the EEPROM from the ADAU1702 to be recalled the next time the program is run.

Two Σ-Δ ADCs and four Σ-Δ DACs provide a 98.5 dB analog input to analog output dynamic. Each ADC has a THD + N of −83 dB, and each DAC has a THD + N of −90 dB. Digital input and output ports allow a glueless connection to additional ADCs and DACs. The ADAU1702 communicates through an I²C bus or a 4-wire SPI port.

Applications

• Multimedia speaker systems
• MP3 player speaker docks
• Automotive head units
• Minicomponent stereos
• Digital televisions
• Studio monitors
• Speaker crossovers
• Musical instrument effects processors
• In-seat sound systems (aircraft/motor coaches)