Hi
Our customer has a question about PCM1774 DAC gain.
He intended to set the gains in 0dB, but measurement gain was 5.1dB smaller than resister settings.
The register settings are as follows:
address value
0x40 0x33
0x41 0x33
0x44 0x3f
0x45 0x3f
0x46 0x01
0x54 0x05
0x56 0x20
0x49 0xec
0x48 0x03
0x58 0x11
0x4A 0x05
0x52 0x30
The register values without mention are default setting.
Input condition is follows:
Sample rate : 22.05 kHz in master mode
Interface format : I2S
Input data : -9.6 dBFS 1kHz sinewave
Measurement output level is 520 mVp-p.
20*log10(0.52V/2/sqrt(2)) = -14.71 dBV.
Where, the output voltage 1 Vrms at 0dBFS.
The difference is -5.1dB.
Best regards,
Akio Ito
