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發表於 2008-12-23 13:21:11
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原帖由 monkeybad 於 2008-12-23 11:27 AM 發表 . B8 D9 ]2 t1 h1 f# r3 b
雖然SDM ADC是用192K當作sample rate, 但是要處理的聲音信號還是在20K(這是人耳廳的到的的頻寬)
f u8 K" S, N1 j# U& e6 D: @9 XSDM ADC是用over sampling的技巧讓SNR提高, 所以sample rate通常會比信號的頻寬要大上許多倍 % e* G' m5 i6 S7 W P# H& R. h: u
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20K is the BW of human hearing, ; r8 ~. ]2 W! l
what is the difference of 44.1/48/96/192KHz data sample rate in audio when this signal is over 20KHz?7 T0 D# L# ]0 o3 ?; C j, z
SDM ADC uses over sampling for gaining high SNR. the oversampling rate will be 64/128/256 fs.- F, h+ Y* i7 B0 S0 u, D
the fs is 44.1/48/96/192KHz. + p- p' J T$ q) i# X( T
SDM ADC with over sampling rate is right point, but sample rate didn't have direct relation with SDM. |
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