Philips Semiconductors is the leader in USB audio technology having been the first to demonstrate its feasibility at WinHEC '96, which was closely followed by the launch of the world's first USB audio Digital to Analog Converter (DAC), the UDA1321. The company continues to innovate with the launch of the world's first integrated USB audio codec, the UDA1325. This provides advanced USB audio handling for superb sound at a build cost that is much less than the current non-integrated solutions and also quicker and easier to implement for a quicker time to market.

It integrates together the functionality of the company's USB transceiver, Digital to Analog Conversion, and USB engine on an 80C51 microcontroller core along with digital and analog filtering, tone and volume control, and buffering.

'As the appointed author of the USB Audio Device Class specifications, Philips Semiconductors is able to create USB audio products that make the most of the great potential of creating high performance, high quality audio over USB,' explained Johan van Ginderdeuren, Philips' USB strategic co-ordinator. 'Before USB this could not be easily achieved because of the electronically harsh and noise environment within a computer. USB enables the signals to be taken outside the PC in a digital format right up to the speakers and so removing the possibility for interference. It also removes the need for sound cards in the PC as all their functionality is now handled in software on the host processor and by the USB audio peripheral, which enables impressive, multi-channel surround sound to be easily achieved as well. All of which, combined with Hot Plug&Play, is in line with the future evolution of the PC with concepts such as the Simply Interactive PC (SIPC) and the OnNow initiative.'

When the notion of USB audio first surfaced I thought it was a great idea -- if it could be implemented; then Philips showed it could be, at least in one direction. Now we have a product that will keep audio inside the computer digital, as it should be: that may sound like an oxymoron for an analog engineer but it surely is how it should be, with the most-possible digital functionality in the PC itself and analog processing as far away from the nasty data lines as possible.

The IC contains the full functionality of the USB interface requirements as well as a well-performing codec, and both the digital and analog filtering needs and level/frequency control. It is difficult to predict anymore how features such as USB will be accepted in the marketplace but a large proportion of PCs seem to be USB-equipped and certainly the system makes life very easy interconnecting devices. My personal feelings are that a newly-delivered and configured PC would be more likely still to be fitted with sound cards until additional features can be delineated to the consumer, or until the quality improvement is blatantly obvious. In the meantime if a PC is being retrofitted -- and has USB capability -- would make devices using this IC rather attractive.

Getting analog audio way-the-heck out of the PC is, to me, a major breakthrough and a prelude to dramatically improved audio performance. The negative about the technology's future is the unknown degree to which the processor manufacturers will push for audio on the motherboard. The price is attractive at $9.00 for the UDA1325 in 10,000 lots. Engineering samples in QFP64 packages are available now with volume production in early 1988.