Motorola Mobility LLC T56KT1 User Manual

Page of 116
Audio Interface
40
 G30 - Module Hardware Description
December 15, 2009
Isolate the audio signals by a surrounding ground plane or shields.
Filter internal supplies and signals that may indirectly affect the audio circuits, from noises 
and voltage drops.
Analog Ground
The G30 interface incorporates a dedicated analog ground contacts, AGND pads 52, 54 (of the 81 
pin LGA interface), which are internally connected to the G30's ground. The AGND signal is 
intended to provide a separate ground connection for the application's external audio devices and 
circuits.
This signal provides an isolated ground connection directly from G30, which is separated from 
the noisy digital ground of the application. It is recommended to connect this signal to analog 
audio devices and circuits used by the application. Using a separate analog ground minimizes 
audio noises and improves the audio circuit's immunity from external interferences.