External microphone circuitry is biased by Retu ASIC MicB2 bias voltage output. The circuitry provides a
symmetrical connection for the microphone from the Pop-Port
TM
connections, XMICN and XMICP, to Retu ASIC
inputs, Mic2P and Mic2N.
Figure 113 External microphone circuitry (Pop-Port connects to the right side)
Internal earpiece
Internal earpiece is used for the HandPortable (HP) call mode. A dynamic 7 x 11mm earpiece capsule is connected
to Retu ASIC’s differential output EarP and EarN.
Earpiece capsule is assembled to fold unit (inside of display frame), but some filter components are also in
engine PWB.
Figure 114 Internal earpiece circuitry
Internal speaker
Internal speaker is used for Internal HandsFree (IHF) call mode.
A dynamic 16mm speaker is connected to Retu ASIC’s outputs HFSpP and HFSpN.
IHF amplifier integrated in Retu is a Digital Pulse Modulated Amplifier (DPMA).
RM-42
Nokia Customer Care
System Module
Page 9–28
Company Confidential
9241872 (Issue 1)
Copyright ©2005 Nokia. All Rights Reserved.