Earpiece; Hands-Free Interface; Headset Jack Interface - LG G7100 Service Manual

3.14 Earpiece

The earpiece is driven directly from AD6521 VOUTNORP (#K8) and VOUTNORN (#K7) pins and the
gain is controlled by the PGA in an AD6521.
The earpiece is placed in the folder cover and contacted to LCD PCB.

3.15 Hands-free Interface

The audio out (VOUTAUXP & VOUTAUXN) to the hands-free kit consists of a pair of differential
signal from AD6521 auxiliary outputs (#K9, #K6), which are tracked down the board to carkit
connector (CN300) at the base of the handset. The DC level of the signal is supplied to the
VOUTAUX pin.

3.16 Headset Jack Interface

This phone chooses a 3-pole type ear-mic jack which has three electrodes such as Receiver +,
Mic+, and GND. This type usually supports only single-ended configuration in the audio path. But
most of phones use the common interface.
Figure 3-15. Earpiece
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3. TECHNICAL BRIEF