An analogue electret microphone is connected to N2200 Mic1P and Mic1N inputs via asymmetric electrical
connection.
The microphone is biased by ASIC N2200.
Figure 45 Internal microphone circuitry
External microphone
Galvanic accessories are connected to the AV connector.
Accessory audio mode is automatically enabled/disabled during connection/disconnection of dedicated
phone accessories.
External microphone circuitry is biased by Avilma ASIC MicB2 bias voltage output. The circuitry provides an
asymmetrical connection for the microphone from the AV connector, XMICP to Avilma ASIC input, mic2p and
XMICN, to GND.
Figure 46 External earpiece and microphone circuitry (AV connected on the right)
Internal earpiece
Internal earpiece is used for the HandPortable (HP) call mode. A dynamic 7x11 mm earpiece capsule is
connected to Avilma ASIC’s differential output EarP and EarN.
RM-243
System Module and User Interface
Page 6 –20 COMPANY CONFIDENTIAL Issue 1
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