CODEC Motherboard Manual Version 1.3
Page 45 of 66
April 12, 2016
CODEC Motherboard
21.1
Analog Output Options for NAU8822
Several functional feature options are available related to the analog outputs.
Jumper and
Label on
Motherboard
Jumper Selection
J34
HP-DETECT
Installing this jumper on the motherboard connects the LLIN/GPIO2 pin of the NAU8822 to a pullup resistor tied
to VDDB, and shorted to a lower voltage by the headphone jack in the state when nothing is inserted in the
headphone jack.
Care should be taken to remove J34 if the headset detection function is not needed or being evaluated. This
otherwise creates a large DC offset for the LLIN signal, and may give the appearance the LLIN input is
malfunctioning.
J32
HP_DC-AC
"AC" default position, connecting pins 1-2. Headphone is tied to analog ground and should be AC coupled (J33
and J35 not-installed on motherboard).
"DC" position, connecting pins 2-3. Headphone is tied to AUXOUT2 which should be configured as a virtual
ground, and in which case the headphone may be DC coupled.
J33
HP-DC
Installing J33 causes the left headphone connector output to be DC coupled to the LHP headphone output of the
NAU8822.
J35
HP-DC
Installing J35 causes the left headphone connector output to be DC coupled to the LHP headphone output of the
NAU8822.
H5 (header)
AUX1
This is intended as the two-pin connection for an external ear speaker load, such as a telephony 150-ohm
receiver transducer. This is not a jumper option location and no jumper should ever be installed at this location.
J30
LINE-HP
Position 1-2 Left Line_Out select and Position 2-3 selects Left HP-_Out (Left headphone out)
J31
LINE-HP
Position 1-2 Right Line_Out select and Position 2-3 selects Right HP+_Out (Right headphone out)
Default factory configuration highlighted in color
Table 5: ANALOG OUTPUT OPTIONS
Figure 27: ANALOG OUTPUT OPTIONS
