LG GX300 Service Manual page 58

Figure 3.13.2 Overview of Clocking and Interfaces of Audio Front End
The audio front-end of X-GOLD™213 has the following major operation modes:
• Power-down: All analog parts are in power down and all clocks of the digital part are switched off.
• Audio mode: Digital decimation/interpolation filters are connected to the interface buffers and the
analog part is enabled.
These major modes can be modified by certain control register settings.
• Due to the new gain settings in the TX path, the maximum input voltage is limited to 0.8 Vpp.
• In both voiceband paths, the value range for voice samples is confined to 97.5%, i.e. to [-31948, 31947]
or [8334H, 7CCBH] in X-GOLD™213.
• On the TX path, 83% "1"s on the VTPDM line correspond to a 16-bit value of 7CCBH and 17% "1"s
correspond to a 16-bit value of 8334H at the digital filter output. Thus the usable range is 66%. This
range can be scaled to 100% by Firmware.
• The high-pass functions of the voiceband filters have to be implemented in firmware on TEAKLite®.
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3. TECHNICAL BRIEF
3. TECHNICAL BRIEF
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