Motorola D10 Service Manual page 74

BenQ
3.12 Earphone jack circuit
TXD0
C63 10UF
C60 10UF
AUXOP
IO3DATA_HP_SEL
Data cable
L: Download
H: Earpiece
Hand free
active
1
VR3
R41
AUXI
2K 1UF
RXD0
Description
The earphone Jack circuit is used either for the headset or the data
service. The IO13ACCIN will be pulled to low level when headset or
data cable is plugged in. Here, U8 and U10 are used as the switch
between headset using or data service using which is controlled by the
IO3DATA_HP_SEL.
IO3DATA_HP_SEL is switched from low to high level to identify whether
the headset or the data cable is plug-in by reading the voltage at
EARPHONE_IN. If the voltage at EARPHONE_IN is in the range of
1.0V to 2.4V, the phone recognizes headset is plugged in and
IO3DATA_HP_SEL stays at high to keep U8 and U10 as auxiliary audio
path. If the voltage at EARPHONE_IN is in the range of 2.6V to 2.8V,
the phone identifies data cable plugged in and IO IO3DATA_HP_SEL
switches back to low to keep U8 and U10 as data service path.
R86 U8
3
B0
2.7K
2
Gnd
BGND
1
B1
NC7SB3157
R36
47K
R37
2K
BGND
D21
R38
2 C37
1K 4.7UF
BAS516
BGND
C38
U10
1
B1
R95
20K 2
Gnd
BGND BGND
3
B0
NC7SB3157
When IO13ACCIN is detected as low level,
VR2B_SW
4
A
5
Vcc
6
S
R96
0
U9
1
I1 O1
2
GND
3
I2 O2
EMIF01-10005W5
BGND
VR2B_SW
6
S
5
Vcc
4
EARPHONE_IN
A
V=1.0~2.4 Handfree
V=2.6~2.8 Data-cable
33
Rev 1.0
VR3
TP33
R32
100K
IO13ACCIN
R72
1K
1
J3
2 1
SW GND
5 3
SPK
4 5
MIC MIC
4
Audio Jack
T8 T9
TVS
TVS
BGND
To Nausica
plug in
T2
2
. .
TVS
BGND