Ear Jack - LG MG220 Service Manual

Head set Jack Interface
ABB_HSO
R215 0
HSMICP
When ear-mic set or head set plug is inserted into the receptacle, JACK_DETECT signal which is input
o f ADIN1 in ABB changes from 'H' to 'L'. If hook button is pushed for a second to make a call, then
HOOK _DETECT signal which is input of ADIN4 in ABB goes from 'H' to 'L'. Two signal is separate by
the level of ADIN4 input port. If the level of ADIN4 is 0.00V ~ 0.14V, the pin means 'hook-detect' signal
set, and If the level of ADIN1 is 0.14V ~ 1.60V, the pin mean 'jack-detect' signal set. Also call end has
same mechanism by pushing hook button on the Ear- microphone strap. Ordinarily detection of
pushing hook button is established by signal de-bouncing for about 20ms.

Ear jack

R208 1K
HSMICBIAS
HOOK_DETECT
C218 10u
R213 22
L200 100nH
C219 0.1u
R217
C220
NA 1K
Figure 20. Ear-Jack interface
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3. H/W Circuit Description
V_IO
R209
10K
R210
C214
R211
5.6K
4.7u
47K
R212 100
C217
47p
R214 82
R216 4.7
VA200
C221 C222 C223
68p 27p 27p
R218 33K
JACK_DETECT
R219
22K
C216
10u
J200
5
1
3
4
VA201
2
C224
27p