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WM9712L
AC’97 Audio and Touchpanel CODEC
DESCRIPTION
The WM9712L is a highly integrated input / output device designed for mobile computing and communications. The device can connect directly to a 4-wire or 5-wire touchpanel, mono or stereo microphones, stereo headphones and a mono speaker, reducing total component count in the system. Additionally, phone input and output pins are provided for seamless integration with wireless communication devices.
The WM9712L also offers up to four auxiliary ADC inputs for analogue measurements such as temperature or light, and five GPIO pins for interfacing to buttons or other digital devices. To monitor the battery voltage in portable systems, the WM9712L has two uncommitted comparator inputs.
All device functions are accessed and controlled through a single AC-Link interface compliant with the AC’97 standard. Additionally, the WM9712L can generate interrupts to indicate pen down, pen up, availability of touchpanel data, low battery, dead battery, and GPIO conditions.
The WM9712L operates at supply voltages from 1.8 to 3.6 Volts. Each section of the chip can be powered down under software control to save power. The device is available in a small leadless 7x7mm QFN package, ideal for use in handheld portable systems.
BLOCK DIAGRAM
FEATURES
AC’97 Rev 2.2 compatible stereo CODEC - DAC SNR 94dB, THD –87dB - ADC SNR 92dB, THD –87dB - Variable Rate Audio, supports all WinCE sample rates - Tone Control, Bass Boost and 3D Enhancement
On-chip 45mW headphone driver On-chip 400mW mono speaker driver Stereo, mono or differential microphone input
- Automatic Level Control (ALC) Auxiliary mono DAC (ring tone or DC level generation) Seamless interface to wireless chipset Resistive touchpanel interface
- Supports 4-wire and 5-wire panels - 12-bit resolution, INL 2 LSBs (<0.5 pixels) - X, Y and touch-pressure (Z) measurement - Pen-down detection supported in Sleep Mode Up to 5 GPIO pins 2 comparator inputs for battery monitoring Up to 4 auxiliary ADC inputs 1.8V to 3.6V supplies 7x7mm QFN
APPLICATIONS
Personal Digital Assistants (PDA) Smartphones Handheld and Tablet Computers
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Production Data, November 2011, Rev 4.6 Copyright 2011 Wolfson Microelectronics plc.
WM9712L
TABLE OF CONTENTS
Production Data
DESCRIPTION....................................................................................................... 1
FEATURES ............................................................................................................ 1
APPLICATIONS..................................................................................................... 1
BLOCK DIAGRAM ................................................................................................ 1
TABLE OF CONTENTS......................................................................................... 2
PIN CONFIGURATION .......................................................................................... 4
ORDERING INFORMATION.................................................................................. 4
PIN DESCRIPTION................................................................................................ 5
ABSOLUTE MAXIMUM RATINGS ........................................................................ 6
RECOMMENDED OPERATING CONDITIONS..................................................... 6
ELECTRICAL CHARACTERISTICS ..................................................................... 7 AUDIO OUTPUTS ............................................................................................................ 7 AUDIO INPUTS................................................................................................................ 8 AUXILIARY MONO DAC (AUXDAC)................................................................................ 8 TOUCHPANEL AND AUXILIARY ADC ............................................................................ 9 COMPARATORS ............................................................................................................. 9 REFERENCE VOLTAGES ............................................................................................. 10 DIGITAL INTERFACE CHARACTERISTICS ................................................................. 10 HEADPHONE / SPEAKER OUTPUT THD VERSUS POWER ...................................... 11 POWER CONSUMPTION .............................................................................................. 12
DEVICE DESCRIPTION ...................................................................................... 13 INTRODUCTION ............................................................................................................ 13 AUDIO PATHS OVERVIEW...........................