AD1941:  SigmaDSP® Multichannel 28-Bit Audio Processor

The AD1940/AD1941 are a complete 28-bit, single-chip, multi-channel audio SigmaDSP™ for equalization, multiband dynamic processing, delay compensation, speaker compensation, and image enhancement. These algorithms can be used to compen-sate for the real world limitations of speakers, amplifiers, and listening environments, resulting in a dramatic improvement of perceived audio quality.

The signal processing used in the AD1940/AD1941 is comparable to that found in high end studio equipment. Most of the processing is done in full, 56-bit double-precision mode, resulting in very good, low level signal performance and the absence of limit cycles or idle tones. The dynamics processor uses a sophisticated, multiple-breakpoint algorithm often found in high end broadcast compressors.

The AD1940/AD1941 are a fully programmable DSP. Easy to use software allows the user to graphically configure a custom signal processing flow using blocks such as biquad filters, dyna-mics processors, and surround sound processors. An extensive control port allows click-free parameter updates, along with readback capability from any point in the algorithm flow.

The AD1940/AD1941’s digital input and output ports allow a glueless connection to ADCs and DACs by multiple, 2-channel serial data streams or TDM data streams. When in TDM mode, the AD1940/AD1941 can input 8 or 16 channels of serial data, and can output 8 or 16 channels of serial data. The input and output port configurations can be individually set. The AD1940 is controlled by a 4-wire SPI® port; the AD1941 is controlled by a 2-wire I2C® bus. Other than the control interface, the functions of the two parts are identical.

Applications

• Automotive sound systems
• Digital televisions
• Home theater systems (Dolby digital/DTS postprocessor)
• Multichannel audio systems
• Mini-component stereos
• Multimedia audio
• Digital speaker crossover
• Musical instruments
• In-seat sound systems (aircrafts/motor coaches)