CS42L51_07 Datasheet, PDF (78/88 Pages) Cirrus Logic – Low Power, Stereo CODEC with Headphone Amp

CS42L51
7.3 ADC_FILT+ Capacitor Effects on THD+N
The value of the capacitor on the ADC_FILT+ pin, 16, affects the low frequency total harmonic distortion +
noise (THD+N) performance of the ADC. Larger capacitor values yield significant improvement in THD+N
at low frequencies. Figure 33 shows the THD+N versus frequency for the ADC analog input. Plots were tak-
en from the CDB42L51 using an Audio Precision analyzer.
-60
-64
-68
-72
-76
d
B
-80
F
S
-84
-88
-92
-96
1 µF
10 µF
22 µF
Legend –
Capacitor Value on ADC_FILT+
-100
20
50
100
200
500
1k
2k
Hz
5k
10k
20k
Figure 33. ADC THD+N vs. Frequency w/Capacitor Effects
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