WM8978
Production Data
w
PD, Rev 4.5, October 2011
66
OUTPUT PHASING
The relative phases of the analogue outputs will depend upon the following factors:
1.
DACPOLL and DACPOLR invert bits: Setting these bits to 1 will invert the DAC output.
2.
Mixer configuration: The polarity of the signal will depend upon the route through the mixer path.
For example, DACL can be directly input to the OUT3 mixer, giving a 180° phase shift at the
OUT3 mixer output. However, if DACL is input to the OUT3 mixer via the left mixer, an
additional phase shift will be introduced, giving 0° phase shift at the OUT3 mixer output.
3. Output boost set-up: When 1.5x boost is enabled on an output, no phase shift occurs. When
1.5x boost is not enabled, a 180° phase shift occurs.
Figure 26 shows where these phase inversions can occur in the output signal path.
Figure 34 Output Signal Path Phasing
Summary of Contents for WM8978
Page 11: ...Production Data WM8978 w PD Rev 4 5 October 2011 11 SPEAKER OUTPUT THD VERSUS POWER...
Page 14: ...WM8978 Production Data w PD Rev 4 5 October 2011 14 AUDIO PATHS OVERVIEW...
Page 55: ...Production Data WM8978 w PD Rev 4 5 October 2011 55 Figure 26 Left Right Output Channel Mixers...
Page 60: ...WM8978 Production Data w PD Rev 4 5 October 2011 60 Figure 29 Speaker Outputs LOUT2 and ROUT2...