Backlight And Illumination; Flip Open/Close Switch; Flashlight; Audio Concept - Nokia RH-109 Service Manual

RH-109
System Module Description

Backlight and illumination

In this phone, Display backlight is common by internal LCD and external LCD, The light source comes from
internal LCM, The LCM backlight control has 3 stages for off, dark and bright, the backlight is collocated MMI
conditions to adjust the shading value.

Flip open/close switch

This is a fold phone that system wakes up, when close the cover. It is implemented with a hall sensors mounted
on the main PCB and a magnet to put on B case housing. The hall detector output is active low (0V) and 1.8V
when not active. This arrangement makes the phone able to detect - closed and open position.

Flashlight

Flashlight is support in the product. The external key design on front cover, external key need press more than
1.5s to turn the flashlight On and Off. Other flashlight has the ability to turn on while phone is off.

Audio concept

The functional core of the audio hardware is built in QSC6055.
QSC6055 provides an interface for the transducers. Integrated hands free (IHF) speakers are driven by D-class
audio amplifier and negative charge pump for (HPH) headset.
There are audio transducers:
3 analog input ( 2 MIC input and 1 LINE_IN input )
1 EARPICE for handset
1 IHF (internal hands free) speaker ( integrate D class for speaker driver)
1 HPH for headset
1 LINE_OUT
Issue 1
Figure 10 Audio block diagram
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