LG GT540 Service Manual page 60

3.13.2.2 WM9093 audio interface
The WM9093 is a high performance low power audio subsystem, including headphone driver and Class AB/D
earpiece/speaker driver. The Class D speaker driver support 650mV output power at 3.6V, 1%THD.
The unique dual mode charge pump architecture provides ground referenced headphone outputs removing the
requirement for external coupling capacitors. Class G technology is integrated to increase the efficiency and extend
playback time by optimizing the headphone driver supply voltages according to the volume control.
The flexible input configuration allows single ended or differential stereo inputs. Mixers allow highly flexible routing
to the outputs, A 'voice Bypass' path is also available for low-power voice applications.
The WM9093 is controlled using a two-wire I2C interface. An integrated oscillator generates all internal clocks.
Removing the need to provide any external clock.
Separate mixer and volume controls are provided for each headphone and speaker driver. Automatic Gain control
limits the speaker output signal in order to prevent clipping. DC offset correction to less than 1mV Guarantees a
pop/click-free headphone start up.
The WM9093 is available in a 2.0mm × 2.5mm 20-bump CSP package.
Copyright © 2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes
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3. TECHNICAL BRIEF
LGE Internal Use Only