Micronas USB Audio Controller Drives Digital Audio deeper Into Home Entertainment (0105)

March 22, 2001 - Micronas announced a newly designed and highly integrated family of universal serial bus (USB) audio controllers to drive digital music from the PC deeper into home entertainment systems. Digital music files, once decompressed on the PC by using the computer's processing power, can be streamed into stereo or TV set via the USB.

The UAC 355xB/E family of audio controllers includes a codec, which provides a streaming interface that makes it possible to tie traditional home entertainment systems to the PC via a USB cable. By piggybacking on the power of the PC's expensive central processing unit, consumer electronics equipment can become digital music playback and recording devices at a fraction of the cost of competing solutions, which do require their own processing power.

So far, the PC and home entertainment system were linked through a Sony/Philips digital interface or by an analog interface. Both are unable to drive title information, user interface or remote control. However, USB's high bandwidth and capability of two-way communication enable easy communication between the entertainment system and PC.

"Our solution allows consumer OEMs to use the liquid crystal displays or the on-screen displays of their own systems to show MP3 file play lists," said Kai Scheffer, director marketing PC peripherals at Micronas. "They can even reuse the existing command and control buttons and remote control for MP3 file playback."

"Micronas did not invent convergence products but we make them user friendly and bring them to the consumer market at an affordable price," said Rainer Hoffmann, president and general manager of Micronas Semiconductors at San Jose (CA). "For digital music to become widely accepted and used we need to take it beyond portable devices and integrate it into our every-day appliances. That is the true essence of convergence."

"Besides standalone music players, we see a big market potential for digital music playback and recording capabilities inside cell phones, handheld devices and home entertainment systems," Scheffer added. "We understand what consumer OEMs are looking for: a low priced, one-chip solution they can simply add to their core system to make digital music streaming, playback and recording an added feature in current-generation systems."

With this strategy in mind, Micronas developed a highly integrated one-chip solution, which includes a micro controller with the functionality needed to for the USB interface and a digital signal processing unit with a three-channel D/A converter and a 2-channel (stereo) A/D converter. The three-channel D/A converter with a signal-to-noise ratio (SNR) of better than 96 dB provides the left and right channels for stereo music and the option to feed low frequencies into the third channel for a subwoofer. The two-channel A/D converter achieves a SNR of better than 85 dB, allowing a microphone to be connected directly without the need for a preamplifier and bias circuits.

Optional to the UAC family members are an additional 8 Kb of RAM for the download of firmware and an integrated EEPROM to store the device descriptor and default power up configuration, which identifies newly plugged-in peripherals.

All versions come in a 64-pin PQFP package and are pin compatible. Engineering samples are currently available; mass production will start in July. Depending on the configuration, the UAC 355xB/E family will cost between US$4.50 and US$6.50 in quantities of 100,000.