User Guide

NPM-6/6X

System Module and User Interface CCS Technical Documentation

Page 34 Nokia Corporation. Issue 2 06/03

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.

Figure 10: Internal microphone

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-6/6X 8mm PICO

type earpiece is used.

Figure 11: Internal speaker

18V

UEM

EARN

EARP

22W

1000W@100MHz

18V