RTL8773E Motherboard User Guide
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1) Short J12, and connect J9.3 with J9.2. SPKL_N and SPKR_N are connected together to U3.1
for differential line.
2) Short J8 and J13. SPKL_P and SPKR_P are transmitted to daughterboard directly.
Figure 2-12 Capless connection for Headphone out
ALC105 works on motherboard as audio power amplifier. AOUT_LP and AOUT_RP
are amplified to drive speaker. By shorting J4.5 and J4.6, M4_0 on IO jumper B is
connected to PD# to power off amplifier for low power application, which is active-
low.
The following are the steps to amplify SPKL_P and SPKR_P to drive speakers:
1) Select power source for PA on jumper J14. Connect J14.2 to J14.1, power ALC105 on by
USB_5V. Or connect J14.2 to J14.3, power ALC105 on by battery.
2) Short J17 and J18.
3) Connect CN1 and CN2 to speakers.
Figure 2-13 Audio power amplifier’s schematic