WM9715L Datasheet, PDF (13/77 Pages) Wolfson Microelectronics plc – AC’97 Audio and Touchpanel CODEC

Production Data
DEVICE DESCRIPTION
WM9715L
INTRODUCTION
The WM9715L is designed to meet the mixed-signal requirements of portable and wireless computer
systems. It includes audio recording and playback, touchpanel digitisation, battery monitoring,
auxiliary ADC and interrupt functions, all controlled through a single 5-wire AC-Link interface.
SOFTWARE SUPPORT
The basic audio features of the WM9715L are software compatible with standard AC’97 device
drivers. However, to better support the touchpanel and other additional functions, Wolfson
Microelectronics supplies custom device drivers for selected CPUs and operating systems. Please
contact your local Wolfson Sales Office for more information.
AC’97 COMPATIBILITY
The WM9715L uses an AC’97 interface to communicate with a microprocessor or controller. The
audio functions are largely compliant with AC’97 Revision 2.2. The following differences from the
AC’97 standard are noted:
• Pinout: The function of some pins has been changed to support device specific features.
The PHONE and PCBEEP pins have been moved to different locations on the device
package.
• Package: The default package for the WM9715L is a 7×7mm leadless QFN package.
Audio mixing: The WM9715L handles all the audio functions of a smartphone, including
audio playback, voice recording, phone calls, phone call recording, ring tones, as well as
simultaneous use of these features. The AC’97 mixer architecture does not fully support
this. The WM9715L therefore uses a modified AC’97 mixer architecture with three
separate mixers.
• Tone Control, Bass Boost and 3D Enhancement: These functions are implemented in
the digital domain and therefore affect only signals being played through the audio
DACs, not all output signals as stipulated in AC’97.
Some other functions are additional to AC’97:
• On-chip BTL loudspeaker driver
• On-chip BTL driver for ear speaker (phone receiver)
• Auxiliary mono DAC for ring tones, system alerts etc.
• Touchpanel controller
• Auxiliary ADC Inputs
• 2 Analogue Comparators for Battery Alarm
• Programmable Filter Characteristics for Tone Control and 3D Enhancement
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PD Rev 4.0 December 2007
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