HH
VS1005 VSOS A
UDIO
S
UBSYSTEM
VS1005g
8.2
DC Offset/AGC Audio Drivers
When audio is digitized, two technical issues are DC Offset and Large Dynamic Range.
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Figure 12: Audio with exaggerated DC offset
In an ideal world DC Offset wouldn’t happen. However, in the real world, signals almost
always have a slight DC offset. Note, how the sine wave in Figure 12 does not move
evenly around the center point, but has an offset of about +0.35. While the figure has
been greatly exaggerated, this is a real phenomenon caused by a myriad of different
reasons.
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Figure 13: Audio with DC blocking
DC offset may cause many issues, including increased power consumption, audible
cracks and pops, waring down of speaker elements, and non-ideal audio compression.
Because of this, it is best to remove the audio offset with a DC Blocker algorithm, as
shown in Figure 13. Notice how the offset disappear after a little while (in this case, it
Rev. 3.57
2019-04-10
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