Prema IC supports analog signal processing for audio enhancement

MAINZ, GERMANY. Is digital signal processing always the way to go? Not according to Stephan Klesy, an applications and project manager at Prema Semiconductor. Prema has developed a silicon BiCMOS processes that require only 11 masks for a 2-metal design, which it employs to build low-cost analog ASICs while offering a few standard products. One of the latter, the MZ-01 analog IC, employs a Speaten filter to provide an analog alternative to digital audio enhancement.The Speaten filter, whose implementation in the MZ-01 was developed by Dedekind R&D, controls the perceived distance of sound, augmenting bass and treble frequencies without introducing distortion in mid-range frequencies.

Klesy notes that the Speaten algorithm could be implemented digitally, which might be an effective approach for applications in which a DSP is available and power consumption isn’t a critical spec. But if you’re looking to implement audio enhancement in an add-on to a portable music player, a DSP would be to expensive and power-hungry to be practical. The MZ-01 consumes 50 mW maximum and is tolerant of a wide range of supply voltages: 2 V to 16 V single-ended or ±1 V to ±8 V differential.

The benefits of an analog approach to signal processing were extolled by National Semiconductor’s Brian Halla (who recently announced his retirement) at Electronica 2008, who said it’s time to stop throwing gates at problems. Gates have their place, but they don’t belong everywhere.