PATHHardware Documentation > PowerBook G3 Series 1999

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Sound Interface IC

The sound interface IC, called Screamer, is a custom IC that combines a waveform amplifier with a 16-bit digital sound encoder and decoder (codec). It is similar to the AWAC IC used in older PowerBook models, with three main differences:

• It has better analog performance
• It has a low-power mode
• It includes a separate input used for the modem call progress sound from a PC Card modem.

The Screamer IC is not soldered directly to the main logic board but is on a small card mounted on the main logic board. The sound outputs from the Screamer IC are connected to a pair of LM4861 power amplifier ICs that provide power to drive the speakers.