WM8750-EV1M
HEADPHONE AUTO-DETECT FUNCTION
DBVDD
+1.8V
to
AVDD
+1.8V
to
DGND
+3.6V
+3.6V
AGND
PARALLEL PORT
J5
J4
J1
J2
+5V
J8
J6
RLINE
IN1
DCVDD
+1.42V
to
P E O
N
SW1
0
J10
SW3
5
4 6
3
1
2
1
+3.6V
SW4
SW2
J11
LLINE
IN1
H1
J13
RLINE
IN2
-
SW6
J17
J15
SW5
SW7
J18
J20
J25
OPT
_IN
LLINE
IN2
J24
J23
J21
SPDIF_
IN
H2
RLINE
IN3
SW8
SW9
J28
J27
1
1
J33
J32
SPDIF_
OUT
1
1
J35
J34
J37
1
1
J36
LLINE
IN3
J38
1
J31
1
J47
HPVDD
+1.8V
to
+3.6V
Figure 34 Headphone Auto Detect Setup
One of the features of the WM8750 is a headphone auto-detect function. This can be
enabled on the WM8750-EV1B by the making the following hardware and software settings.
HARDWARE SETUP
1. Designator R50 should be populated with a 0R resistor.
2. Switch SW8 should be set to the OFF (centre) position.
3. Designator R49 should be populated with a 47K resistor.
4. Connect speakers to the R/LOUT2 outputs.
5. For this recommended setup the rest of the jumper and switch settings should be
as shown in Table 7.
SOFTWARE SETUP
1. Press the ‘DAC Setup’ button.
2. Open the Tone Control panel and set the ‘Headphone Switch’ to Enable. Press the
Tone Submit button.
The headphone auto-detect function should now be active. With no headphone connected to
the 3.5mm jack socket (J46) audio should be output from the speakers connected to
R/LOUT2. When the headphone is plugged into 3.5mm jack socket (J46), the audio should
not be output from the speakers connected to R/LOUT2 and only be output from the
headphones.
Refer to the WM8750 datasheet for further details of this, and all other functions offered by
the WM8750.
Rev 2.0, February 2005
46
w
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
