Nokia 5140 Manuales De Servicio

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Nokia Customer Care
System Module and User Interface
NPL-4/5
Issue 1 05/04
Copyright © 2004 Nokia Corporation. All rights reserved.
Page 71
Internal speaker
There is a dynamic earpiece with impedance of 32 ohms. 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 UEMEK and the 
earpiece driver (EARP & EARN outputs) is a fully differential bridge amplifier with 6 dB 
gain.
Figure 33: IEarpiece Connection
IHF
The NPL-4/5 uses the D-class amplifier to gain signal to IHF speaker. The integrated 
Hands Free Speaker is used to generate polyphonic ringing tones, FM radio, PoC and IHF 
audios. Speaker capsule is mounted under the antenna. Spring contacts are used to con-
nect the IHF Speaker contacts to the system PWB.
Class-D amplifier, it produces high efficiency, which leads to the lower current consump-
tion and makes the thermal issues negligible as well compared to the traditional solu-
tions.
Figure 34: IHF Connection
1000
Ω@100MHz 
EARP 
EARN 
UEMEk 
14V 
14V 
27pF
 
27pF
 
 
UPP 
UEMEk 
LM4667 
IN+ 
IN- 
PAOUTP 
PAOUTN 
10n 
10n GAINSEL 
SHUTDOWN
V01 
V02 
GenIO(14) 
VBatt 
100n
1u 
220ohm/100MHz