Headset Interface - LG KG110 Service Manual

3. TECHNICAL BRIEF
R275 0
SPK_P
R276 0
SPK_N
AMP_SHDN
AMP_SHDM

3.3.8 Headset Interface

This phone has 5 electrodes such as GND, AUXIP, ACK_DETECT, HOOK_DETECT.
This type supports mono sound.
Switching from Receiver to Headset Jack
If jack is inserted, JACK_DETECT goes from high to low.
Audio path is switched from receiver to earphone by JACK_DETECT interrupt.
Switching from Headset Jack to Receiver
If jack is removed, JACK_DETECT goes from low to high.
Audio path is switched from earphone to receiver by JACK_DETECT interrupt.
Hook detection
If hook-button is pressed, HOOK_DETECT is changed from low to high.
This is detected by AUXADC2.
And then hook is detected.
VBAT
AUDIO
C280
1u
U202
MAX9718
4 10
IN+ OUT+
2 6
IN- OUT-
1 5
RCV_P
SHDN BIAS
3 8
RCV_N
SHDM NC
C277
0.1u
R283 NA
R284 NA
Figure 3-10: Main Speaker Circuit
VEXT
C271
1u
U201
MAX4684EBC_T
C4 C2
NO1 IN1
A4 A2
NO2 IN2
C1 C3
NC1 COM1
A1 A3
NC2 COM2
SPK_RCV_P
C272
39p
SPK_RCV_N
C273 C274
39p 39p
24
SPK_RCV_SEL
SELECT
HIGH SPEAKER
LOW RECEIVER
SPK_RCV_SEL
R271 0
SPK_RCV_P
R272 0
SPK_RCV_N
R280
(FOR TUNING NOISE)
10K
RC201
RC202