User Guide

CCS Technical Documentation System Module and User Interface

NPM-6/6X

Issue 2 06/03 Nokia Corporation. Page 33

Figure 8: External audio connection

When the accessory is inserted and the microphone path is biased the HookInt signal

decreases to 1.8V due to the microphone bias current flowing through the resistor. When

the button is pressed the microphone signals are connected together, and the HookInt

input will get half of micbias dc value 1.1 V. This change in DC level will cause the Hook-

Int comparator output to change state, in this case from 0 to 1. The button can be used

for answering incoming calls but not to initiate outgoing calls.

internal Audio

IHF Speaker & Stereo Audio Amplifier

Integrated HandsFree Speaker is used to generate alerting and warning tones in NPM-6/

6X. IHF Speaker is controlled by an Audio amplifier . Speaker capsule is mounted in the

C-cover. Spring contacts are used to connect the IHF Speaker contacts to the main PWB.

Figure 9: IHF speaker and amplifier

XMIC N

XMIC P

3 * EXC24CB102U

Ω

@ 100MHz

MIC

ASIP

2* 33nF

UEM

100nF

MIC BIAS

HSEARN

HSEARP

HSEARRN

HSEARRP

radio

14V/46V

varistors

1nF

Stereo

audio

Amplifier

22pF

BIAS ground

SYSTEM CONNECTOR

Stereo Radio

Audio

PhoneAudio

Antenna signal