Designer’s Guide Community

Pages: 1

Oversampling converter specifications (Read 1832 times)

ywguo Community Fellow Offline Posts: 943 Shanghai, PRC	Oversampling converter specifications Feb 28^th, 2007, 6:50pm Hi, Guys, I am studying oversampling converters. I want to know if the definition for oversampling converter specifications is different from that of nyquist converters. For eg., should we integrate the noise from DC to fs/2 or oversampling ratio � fs/2 on calculating SNDR? BTW: What is the stopband attenuation? Thanks Yawei
Back to top	IP Logged

vivkr

Community Fellow

Offline

Posts: 780

Re: Oversampling converter specifications
Reply #1 - Mar 1^st, 2007, 2:33am

ywguo wrote on Feb 28^th, 2007, 6:50pm:

Hi, Guys,

I am studying oversampling converters. I want to know if the definition for oversampling converter specifications is different from that of nyquist converters. For eg., should we integrate the noise from DC to fs/2 or oversampling ratio � fs/2 on calculating SNDR?

BTW: What is the stopband attenuation?

Thanks
Yawei

Hi Yawei,

You are only interested in the bandwidth from 0 to fs/(2.OSR). The idea is that the stopband attenuation of the digital filter that follows
is high enough. This is anyway needed as your shaped noise power is quite high outside the signal band and rises rapidly after fs/(2.OSR).
Typically, the order of the digital filter needs to be 1 higher than the order of the delta-sigma modulator.

Regards
Vivek

IP Logged

Pages: 1

‹ Previous topic | Next topic ›