ATSAM2195 ATMEL [ATMEL Corporation], ATSAM2195 Datasheet - Page 15

• Manufacturer Part Number: ATSAM2195
• Description: Audio Processing
• Manufacturer: ATMEL [ATMEL Corporation]

8. Dither Modes Description (Dithering Signal Programmability)
6308A–DRMSD–10-May-07
dith[1:0]
00
01
10
11
Mode description
No dither
Dither signal power = -30dBFS
Dither signal power = -27dBFS
Dither signal power = -24dBFS
Dithering is used to attenuate the so-called idle tones caused by correlation between DAC input
signal and truncation noise. This correlation manifests as spurious signals in the audio band and
hence can be perceived by the user. The addition of a random digital signal to the truncator input
in the digital modulator has been proven to be very effective to reduce the presence of idle
tones. However, this is actually a noisy signal so that its power must be traded-off with the
required dynamic range. For better control, the ATSAM2195 allows programmability of the dith-
ering signal power as shown below.
Comments
Minimum recommended dither.
Typical value
Maximum recommended value. Above it dither noise may
become dominant.
ATSAM2195
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