CS5571 View Datasheet(PDF) - Cirrus Logic
Part Name
Description
MFG CO.
'CS5571' PDF : 32 Pages View PDF
3/25/08
10:56
CS5571
Figures 14 and 15 illustrate the small signal performance of the CS5571 with a 5.55 kHz signal at -80 dB
down. Figure 14 is with DITHER on and Figure 15 is with DITHER off. At -80 dB the signal is 1/10,000
of full scale, having a peak-to-peak magnitude of only a few codes. For small signals, DNL errors and
quantization errors can introduce distortion because the error in the code size, or the quantization error
without adequate dither, are a much greater percentage of the signal than with a full-scale input. Figure
15, with DITHER off, illustrates that distortion components can be introduced when there is not adequate
dither to randomize the quantization error.
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-80
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-140
-160
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5.55 kHz, -80 dB
32k Samples @ 100 kSps
Dither On
10k
20k
30k
40k
50k
Frequency (Hz)
Figure 14. Spectral Performance, -80 dB
Dither On
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-20
-40
-60
-80
-100
-120
-140
-160
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10k
20k
30k
40k
50k
Frequency (Hz)
Figure 15. Spectral Performance, -80 dB
Dither Off
Figures 16 and 17 illustrate DITHER on and DITHER off with a 5.55 kHz input at -100 dB. At -100 dB the
signal is only about 41 microvolts peak to peak. This is less than the one code width which is about
62.5 microvolts.
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-20
-40
-60
-80
-100
-120
-140
-160
0
10k
20k
30k
40k
Frequency (Hz)
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-20
-40
-60
-80
-100
-120
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-160
50k
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10k
20k
30k
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50k
Frequency (Hz)
Figure 16. Spectral Performance, -100 dB
Dither On
Figure 17. Spectral Performance, -100 dB
Dither Off
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DS768PP1
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