Power Amplifier - Nokia 6111 RM-82 Service Manual

RM-82
Nokia Customer Care System module
Figure 130 Audio block diagram
Earpiece
The earpiece is driven by differential signals from UEMEK (EARP & EARN). It is located on the bottom/back side
of the UI board. The connection to the PWB is made with two metal clips, which are glued to the C-cover.
Microphone
Two inputs are used from UEMEK, one for the normal internal microphone and the other for the headset. The
third microphone input is used for FM. The microphone makes contact with the PWB via spring contacts.
Vibra
The vibra is an SMD-mounted vibra. The rated voltage is 3.2 V and it needs a duty cycle between 140 and 155
Hz to reach the resonance frequency.

Power amplifier

The power amplifier, also called boomer, is a high efficiency filter free differential amplifier. It has a gain of
+6 dB. The differential output drives the internal handsfree speaker, IHF. The outputs go into a high
impedance state when powered down.
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