Following IDT's notebook clock device and Fujitus's hard disk plans, there's another development that could impact upcoming Apple laptops. SigmaTel, which makes mixed-signal integrated circuits for the portable consumer electronics and computing markets, has introduced a new family of high-fidelity high-definition (HD) audio codecs.

Ron Edgerton, president and CEO of SigmaTel, says the new codecs will allow for digital microphone capabilities and the ability to implement audio and modem functionality directly on the computer motherboard. The new audio solutions—the SigmaTel STAC9202 and STAC9251—feature digital microphone capabilities. The STAC9250 also provides support for the implementation of an audio-modem-on-motherboard (AMoM) solution when combined with the Silicon Laboratories Si3080 Line Side modem Direct Access Arrangement (DAA) chip. The new High Fidelity HD Audio codecs will enable notebook manufacturers to add advanced capabilities to their systems while keeping costs manageable, Edgerton says.

The STAC9202 and STAC9251 will allow laptop manufacturers and designers to design notebook computers with built-in digital microphones that improve voice input for applications such as Voice over Internet Protocol (VoIP) telephone service, voice instant messaging (IM) and speech recognition, he adds. Digital microphones offer high-definition audio input and unlike analog microphones, don't require shielded cabling. This reduces design complexity and assembly costs, Edgerton says.

What's more, the digital microphones are smaller, enabling optimal acoustic placement in the LCD bezel and reducing noise present in typical analog microphone implementations. Additionally, the STAC9250 and STAC9251 A-MoM technology allows designers to place the modem directly onto the computer motherboard, instead of as a separate component on a dedicated daughter card within the computer system.