The Designer's Guide Community Forum

The Designer's Guide Community Forum
https://designers-guide.org/forum/YaBB.pl
Design >> RF Design >> sigma delta modulators for PLL
https://designers-guide.org/forum/YaBB.pl?num=1278355132

Message started by vp1953 on Jul 5^th, 2010, 11:38am

Title: sigma delta modulators for PLL
Post by vp1953 on Jul 5^th, 2010, 11:38am

I am looking for material to understand the working of sigma delta modulators for fractional PLL's. Specifically my interest is in MASH type 3 order or higher. It is very difficult to come across references that discuss this and so if anyone can point to any relevant references, it will be greatly appreciated.

Also was wondering what are the tools out there that can help with the design (e.g. Matlab)?

Thank you in advance

Title: Re: sigma delta modulators for PLL
Post by raja.cedt on Jul 5^th, 2010, 8:15pm

hi,
start with dean book and mean while just read about sigma delta modulator basics(for this you can refer any basic ADC book)

Thanks,
Rajasekhar

Title: Re: sigma delta modulators for PLL
Post by vp1953 on Jul 6^th, 2010, 10:04am

Hi Rajasekhar,

Dean's book discusses only a first order SDM. Most ADC's use an analog SDM, not the purely digital SDM's used for dithering in frac plls. I am looking for material on digital SDM with order at least 3.

Thank you.

Title: Re: sigma delta modulators for PLL
Post by Mayank on Jul 6^th, 2010, 9:00pm

Refer "Understanding Delta-Sigma Converters" by Richard Schreier & Gabor C. Temes.

You will get MASH 1-1, 1-1-1, 2-1 & so on structures which are commonly used today.

--M

Title: Re: sigma delta modulators for PLL
Post by vp1953 on Jul 7^th, 2010, 8:59am

Hi Mayank,

Thank you very much for the reference. This is what i was looking for.

Title: Re: sigma delta modulators for PLL
Post by Alexandar on Aug 20^th, 2010, 2:19am

Mayank wrote on Jul 6^th, 2010, 9:00pm:

Refer "Understanding Delta-Sigma Converters" by Richard Schreier & Gabor C. Temes.

You will get MASH 1-1, 1-1-1, 2-1 & so on structures which are commonly used today.

--M

Is the book you mention better than this one:

Delta-Sigma Data Converters: Theory, Design, and Simulation by Steven R. Norsworthy, Richard Schreier, and Gabor C. Temes

For the latter one I hear it is very detailed on different implementations of SDM, and is quite brief on the basic stuff. How is that with the one you mention?