User Guide

Figure 109 External earpiece circuitry (system connector connected on the right)

Pop-port

connector

Pop-Port

connector provides a fully differential 4–wire stereo line-level output connection and fully

differential 2-wire mono line-level or microphone level input connection.

The handsfree driver in Retu is meant for the headset.

The output is driven in a fully differential mode. In the fully differential mode, the handsfree pin is the

negative output and the HFCM pin is the positive output. The gain of the handsfree driver in the differential

mode is 6 dB.

The earpiece and headset signals are multiplexed so that the outputs cannot be used simultaneously.

RM-42

Nokia Customer Care System Module

Page 9 –32 COMPANY CONFIDENTIAL Issue 2