Comments on: Continuous time sigma-delta ADC noise shaping filter circuit architectures

By: Unity STF | A sigma-delta linearization method | Circuit Design

Unity STF | A sigma-delta linearization method | Circuit Design — Mon, 24 Nov 2008 02:57:59 +0000

[...] a previous post, I discussed the trade-offs in linearity of several continuous-time sigma-delta schemes. In this [...]

By: greg w

greg w — Thu, 20 Nov 2008 20:15:21 +0000

have a look on Schreier’s publication: a sinc filter has to be added to loop filtering
don’t forget to add capa comm dac because it’s reducing jitterclock constraint..

By: Poojan Wagh

Poojan Wagh — Tue, 18 Nov 2008 21:00:53 +0000

@Friedel Gerfers:
Thanks for the comment, Friedel. I agree with your comment. A CT SDM is still effectively a discrete-time system (or can be modeled that way). Perhaps I will post about that in the future.
Also, your point is well taken that one can view the CT SDM modulator as an anti-alias filter ahead of the quantizer (albeit with the loop closed around both). Thanks!

By: Friedel Gerfers

Friedel Gerfers — Tue, 18 Nov 2008 20:24:12 +0000

Poojan,

please note that a CT SDM is still a discret system due to the sampled quantizer.
Furthermore, since the quantizer is placed behind the CT filter, a CT SD ADC has an inherent anti-aliasing filter.

By: Continuous time sigma-delta ADC noise shaping filter circuit architectures | Circuit Design

Tue, 18 Nov 2008 13:19:31 +0000

[...] This post has been updated. Please visit the new location. [...]