Internal Microphone; External Microphone - Nokia RM-132 Service Manual & Parts Manual

RM-132; RM-133
System Module Nokia Customer Care
Figure 86 Audio block diagram

Internal microphone

The internal microphone is used for HandPortable (HP) and Internal HandsFree (IHF) call modes.
An analogue electret microphone is connected to the EM ASIC (N2200) Mic1P and Mic1N inputs via asymmetric
electrical connection.
The microphone is biased by the EM ASIC MicB1 bias voltage output.
Figure 87 Internal microphone circuitry

External microphone

Galvanic accessories are connected to the system connector.
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