Chip Combines An Audio Codec With Pen Input Functionality

Touted as an industry first, the WM9705 IC couples a high-performance portable audio codec with pen-input functionality. At the same time, it conforms to Intel's AC'97 Revision 2.1 specification and is said to be the first ever audio codec to maintain this audio standard while integrating advanced features such as a stereo headphone driver and touch screen controller. Expected to have a significant impact on the PDA industry, the chip delivers a convergence of audio and PDA facilities to next-generation portable information devices.
The audio portion of this device, based on the company's WM8731 core, provides full-duplex, 18-bit codec functions and supports variable sample rates from 8 to 48 ksamples/s with high signal-to-noise ratio. Additional audio features include 3-D sound enhancement, line-level outputs and stereo-buffered headphone outputs. Microphone and headphone switching are also provided, making the IC well-suited for such applications as mobile telephony.
The chip also integrates a four-wire, touch-screen controller complete with on-chip screen drivers. Pen-down detection and pressure-measurement capabilities round out this portion of the device.
Other features of the WM9705 include battery monitoring and extensive power management features. The chip is targeted at mobile devices, palm computers and Windows CE machines.
With production quantities scheduled for the third quarter of 2001, price is $5.48 each/1,000 in a 48-pin TQFP package.