Internal Microphone; Internal Speaker - Nokia NPM-6 Series Manual

System Module and User Interface

Internal Microphone

The internal microphone is connected to the UEM microphone input. The microphone
input is symmetric and microphone bias is provided by the UEM. The microphone input
on the UEM is ESD protected. Microphone capsule is mounted in the System Connector
Assembly. Spring contacts are used to connect the microphone contacts to the main
PWB.

Internal Speaker

The internal earpiece is a dynamic earpiece with impedance of 32 ohms. The earpiece
must be low impedance one since the sound pressure is to be generated using current
and not voltage as the supply voltage is restricted to 2.7V. The earpiece is driven directly
by the UEM and the earpiece driver in UEM is a bridge amplifier. In NPM-6 8mm PICO
type earpiece is used.
UEM
EARP
EARN
Page 34
Figure 10: Internal microphone
Figure 11: Internal speaker
22W
22W
18V 18V
ãNokia Corporation.
CCS Technical Documentation
1000W@100MHz
Issue 1 01/03