DA7212 AUX input doubled

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pawelp28
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DA7212 AUX input doubled

Hello,

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.

thank you

Device: 
ED_Dialog
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Hello Pawelp28,

Hello Pawelp28,

 

I will look into this, I will get back to you soon. 

 

Kind regards,

Elliott Dexter 

ED_Dialog
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Hello Pawelp28,

Hello Pawelp28,

When the inputs are set in single-ended mode (AUX is always single-ended, MIC depends on the setting of MIC_x_AMP_IN_SEL) they have a built in +6 dB of gain due to the internal conversion from single-ended to differential.  This maximises the dynamic range. Therefore 1 Vpp in gives 2 Vpp out (assuming all gains are set to 0 dB). This gain can be removed by setting AUX_x_AMP_GAIN = -6 dB (0x31).

Kind regards,

Elliott Dexter 

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