I just got the DA7212 Evaluation Board. I am generating a 1kHz 1Vpp with a signal generator and injecting it into AUX_L and observing the output on HP_L and I am seeing 2Vpp.
The codec is configured for straight through (no ADC/DAC). I also tried going through the MIXN_L (same result). If I inject the signal to MIC1_P then 1Vpp in is 1Vpp out. All gain settings are set to 0dB.
Can you please give some insight as to why the output is doubled when injecting it into the AUX? I tried various configurations and I can't seem to get the expected result.