Nokia 5140 Manuales De Servicio

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NPL-4/5
System Module and User Interface
Nokia Customer Care
Page 70
 Copyright © 2004 Nokia Corporation. All rights reserved.
Issue 1 05/04
Driver will work as constant current generator increase or decrease the output voltage 
for LEDs to keep the current stable. Serial resistance 33is used to create the current 
limit with transistor Vbe voltage.
Figure 31: Flashlight Driver and Control 
Internal microphone
The internal microphone capsule is mounted into the system connector assy, which is 
connected to engine board with springs. Microphone is omni directional and it’s con-
nected to the UEMEK microphone input MIC1P/N. The microphone input is symmetric 
and the UEMEK (MICB1) provides bias voltage. 
Figure 32: Microphone Connection
 
R=33Ω 
VLED 
CallLED2
R=47Ω 
 
33nF 
UEMEk
MIC1B 
MIC1P 
2k2 
33nF 
MIC1N 
1k
1000
Ω@100MHz 
2k2 
2.2uF 
1nF
1nF
1k
27pF
27pF
27pF
220