Figure 48 Audio block diagramInternal microphoneThe internal microphone is used for HandPortable (HP) and Internal HandsFree (IHF) call modes. Also if theaccessory headset does not have microphone, the phone uses the internal microphone. An analogue electretmicrophone is connected to the EM ASIC N2200 Mic1P input via asymmetric electrical connection. Themicrophone is biased by the EM ASIC MicB1 bias voltage output.External microphoneGalvanic accessories are connected to the 3.5mm AV-connector. Accessory audio mode is automaticallyenabled/disabled during connection/disconnection of dedicated phone accessories. External microphone isconnected to EM ASIC N2200 input Mic2P and Mic2N. Mic2P, Head_Det line of EM ASIC N2200 and CompositeVideo input from application ASIC are multiplexed to the same AV-connector line.RM-313System ModuleIssue 1 COMPANY CONFIDENTIAL Page 6 –21Copyright © 2007 Nokia. All rights reserved.
