
CCS Technical Documentation
System Module and User Interface
NSB-9
Issue 1 04/03
Nokia Corporation
Page 41
Internal Speaker
The internal earpiece is mounted into the LCD metal frame. The earpiece is a dynamic
earpiece with a 32 ohm impedance. The earpiece is 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. The earpiece driver in UEM
is a bridge amplifier.
Figure 14: Internal speaker
connections
Integrated Hands Free
Integrated Handsfree (IHF) makes it possible to keep the phone for example on desk and
keep both hands free. When IHF mode is activated, internal microphone is used as in HP-
mode and IHF speaker is used instead of earpiece.
The FM-radio can be listened from the IHF speaker as well, if a headset is connected
(FM-radio antenna).
The stereo audio amplifier supports four inputs and three outputs. It is capable of deliv-
ering 340mW of continuous averahe power into a mono 8Ohm bridged-tied load and
25mW per channel of continuous average power into stereo 32Ohm loads (when using
3V supply voltage). Stereo signal from FM-radio is connected to Rin and Lin inputs, and
XEAR signal from UEM is connected to PhoneInHS input of stereo audio amplifier. Phone
IHF line includes discrete RC high-pass filtering in order to cut off low frequencies from
IHF speaker. SPKROut lines are connected to IHF speaker. PhoneInIHF to SPKROut path
has fixed 12dB gain.
2x1000
Ω
Ω
Ω
Ω
@100MHz
EARP
EARN
UEM
27p
27p
8mm PICO
5140247
Содержание NSB-9
Страница 14: ...NSB 9 CCS Technical Documentation Page 8 Nokia Corporation Issue 1 04 03 This page left intentionally blank ...
Страница 59: ...CCS Technical Documentation NSB 9 Series Transceivers Issue 1 04 03 Nokia Corporation Parts List ...
Страница 80: ...NSB 9 CCS Technical Documentation Page 2 Copyright Nokia All rights reserved Issue 1 04 03 ...
Страница 116: ...NSB 9 Company confidential CCS Technical Documentation Page 40 Copyright Nokia All rights reserved Issue 1 04 03 ...
Страница 143: ...CCS Technical Documentation NSB 9 Series Transceivers Issue 1 04 03 Nokia Corporation Service tools ...
Страница 166: ...NSB 9 Service tools CCS Technical Documentation Page 24 Nokia Corporation Issue 1 04 03 ...
Страница 175: ...CCS Technical Documentation NSB 9 Series Transceivers Issue 1 04 03 Nokia Corporation Troubleshooting Instructions ...