topic Re: MC9S12XDP512 Missing PLL Filter Calculator in S12 / MagniV Microcontrollers

MC9S12XDP512 Missing PLL Filter Calculator

christianpeters — Thu, 13 Nov 2014 15:37:28 GMT

Dear all,

in AN3262 a PLL Filter Calculator is described, but in reality it is for 9S12 an cannot be used for the far faster S12X Family,

Is there an apnote using the PLL Filter with the 9S12X family?

Thanks

Re: MC9S12XDP512 Missing PLL Filter Calculator

kef2 — Fri, 14 Nov 2014 07:34:20 GMT

Can't find source URL, I found attached EXE stored in my datasheets folder.

Edward

Re: MC9S12XDP512 Missing PLL Filter Calculator

christianpeters — Tue, 18 Nov 2014 10:07:56 GMT

Thank you Edward,

In the calculators window here are the terms “stability factor” and “damping factor”.

As I found no appnote or document for the calculator, may you explain these terms to me?

Kind regards

Christian Peters

Senior Field Application Engineer

EBV GmbH & Co. KG

Im Technologiepark 2-8

85586 Poing

Tel. +49 8121 774 533

Fx. +49 8121 774 540

Re: MC9S12XDP512 Missing PLL Filter Calculator

kef2 — Tue, 18 Nov 2014 10:49:31 GMT

Stability =50 and damping factor =0.9, I think are things, mentioned XDP512 RM

A.5.3.1 XFC Component Selection

The loop bandwidth fC should be chosen to fulfill the Gardner’s stability criteria by at least a factor of 10, typical values are 50. z = 0.9 ensures a good transient response.

I used default 50 and 0.9 for years without any problems. If I had problems with stability or too slow PLL locking, I would study it deeper/