Analog Ground - Motorola 8900 - Blackberry Curve Cell Phone OEM Car Charger Developer's Manual

Chapter 2: Hardware Interface Description

Analog Ground

The C24 interface incorporates a dedicated analog ground contact, AGND pin 59, which is
internally connected to the C24'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 C24, 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.
December 15, 2008 C24 Module Hardware Description 37