WM9712CLGEFL/RV WOLFSON [Wolfson Microelectronics plc], WM9712CLGEFL/RV Datasheet - Page 33

• Manufacturer Part Number: WM9712CLGEFL/RV
• Manufacturer: WOLFSON [Wolfson Microelectronics plc]

Production Data
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JACK INSERTION AND AUTO-SWITCHING
In a phone application, a BTL ear speaker may be connected across OUT3 and HPOUTL, and a
stereo headphone on HPOUTL and HPOUTR. Typically, only one of these two output devices is used
at any given time: when no headphone is plugged in, the BTL ear speaker is active, otherwise the
headphone is used.
The presence of a headphone can be detected using GPIO1 (pin 44) and an external pull-up resistor
(see “Applications Information” section for a circuit diagram). When the jack is inserted GPIO1 is
pulled low by a switch on the socket. When the jack is removed GPIO1 is pulled high by a resistor. If
the JIEN bit is set, the WM9712L automatically switches between headphone and ear speaker, as
shown below.
Table 20 Jack Insertion / Auto-Switching (1)
Table 21 Jack Insertion / Auto-Switching (2)
REGISTER
ADDRESS
58h
Additional
Functional
Control
JIEN FRC
0
1
1
0
1
X
0
0
1
1
GPIO1 MODE DESCRIPTION
BIT
12
11
X
X
X
0
1
Jack insert detection disabled
(headphone and ear speaker
can be used at the same
time)
Jack insert detection enabled,
headphone plugged in
Jack insert detection enabled,
headphone not plugged in
Force Ear Speaker Mode
Invalid; do not use this setting
LABEL
JIEN
FRC
DEFAULT
0
0
DESCRIPTION
Jack Insert Enable – Takes output of GPIO1
logic
Force Ear Speaker Mode
See table below
Set by
reg.
24h
and
26h
Set by
reg.
24h
and
26h
Set by
reg.
16h
PD, Rev 4.6, November 2011
WM9712L
33