User Guide

Figure 48 Audio block diagram

Internal microphone

The internal microphone is used for HandPortable (HP) and Internal HandsFree (IHF) call modes. Also if the

accessory headset does not have microphone, the phone uses the internal microphone. An analogue electret

microphone is connected to the EM ASIC N2200 Mic1P input via asymmetric electrical connection. The

microphone is biased by the EM ASIC MicB1 bias voltage output.

External microphone

Galvanic accessories are connected to the 3.5mm AV-connector. Accessory audio mode is automatically

enabled/disabled during connection/disconnection of dedicated phone accessories. External microphone is

connected to EM ASIC N2200 input Mic2P and Mic2N. Mic2P, Head_Det line of EM ASIC N2200 and Composite

Video input from application ASIC are multiplexed to the same AV-connector line.

RM-313

System Module

Issue 1 COMPANY CONFIDENTIAL Page 6 –21