ZXCZM800 improves sound of AVRs

Edited by the Electronicstalk editorial team May 22, 2009

Diodes Incorporated has introduced an eight-channel DAC and pre-amplifier chip that reduces component costs and improves the sound for designers of audio video receivers (AVRs) and add-on sound cards.

The ZXCZM800, part of the Zetex Direct Digital Feedback Amplifier (DDFA) product line, will reduce circuit complexity and in high-performance differential mode will deliver a dynamic range (DNR) as high as 126db.

The outstanding performance of the DAC solution complements that of digital amplifiers created using the DDFA chipset.

In consumer and professional audio-product designs that depend on the use of multiple-quality two-channel DACs to achieve mid- to high-level audio performance goals, the ZXCZM800 offers the means to significantly reduce component inventory and PCB size.

With typical mid-range AVRs and sound cards currently producing a DNR of 112dB, the diodes chip can match or improve existing product sound-quality.

For product designers looking to expand a product's feature set, the ZXCZM800 offers the option of pre-amplifier DSP features, simply programmed using an existing system host processor.

For example, by integrating a digital volume-control function - operating on a per channel and/or all channel basis - the chip can simplify product design, improve performance and reduce cost.

A digital multiplexing function allows additional digital inputs to be accommodated and achieves simple implementation of multi-room configuration.

Fourteen user-programmable biquads per channel facilitate filter functions such as parametric EQ.

In terms of DAC performance metrics, the ZXCZM800 offers a maximum resolution of 32 bits, meaning more headroom and less impact on performance with higher input audio-data resolutions.

Maximum sample-rate is up to 192kHz and DNR in single-ended operating mode is 120dB.

For distortion and noise, figures of less than 0.001 per cent are typical for single-ended mode, less than 0.0004 per cent in differential mode.

The ZXCZM800 DAC and pre-amplifier chip is supported by an eight-channel demonstration board, details of which will be made available for volume production DAC and pre-amplifier designs, and includes circuit diagrams, bill of materials and Gerber files.