Service manual

TDMA M3090/M3097: Headset/MIC
B36
Description
When a headset is inserted in J8, the internal speaker and microphone is disabled. The user can now use the headset for handsfree conversation. BOOM_MIC_DET
informs U1000 whether a headset is inserted or not. The st ate of BOOM_MIC_DET is controlled by Q1560.
When the headset is inserted the biasing voltage for the AUX_MIC will no longer be present at the base of the NPN transistor Q1560. This will switch Q1560 off, thus,
allowing BOOM_MIC_DET to be pulled high. When the headset is not inserted, the AUX_MIC biasing voltage is present at the base of Q1560. This condition will
switch Q1560 on, thus, pulling the BOOM_MIC_DET to ground.
J8
HDST_SPKR
AUX_MIC
Q1560
BOOM_MIC_DET
2.75V
AUX_OUT
R1560