XFC Loopfilter C and R values

Started by Adrian Vos November 8, 2002
Hi All,

Is anyone able to help me out with the setting of the Capacitor/resistor
values for the PLL loop filter (going to the XFC pin) on the S12DP256.

I am using a 4MHz crystal, and plan to use the PLL to generate the max bus
frequency of 25MHz (50MHz PLL output). To do this I plan to use a value for
REFDV of 3 and SYNR of 24.

I cannot find any application notes on how to set the resistor and two
capcitors (R0, Cs and Cp).

If someone can point me in the direction of information to do this, or
provide a calculation for me to use, that would be much appreciated.

Regards,

Adrian

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Hi Adrian.

Found in this 68HC12 mailing list:

A PLL components calculator program for the HCS12 is available on the Nohau
web site at:

http://www.nohau.com/s12calc/pll_302.html

Regards,
Gilles At 08:11 AM 11/8/2002, you wrote:
>Hi All,
>
>Is anyone able to help me out with the setting of the Capacitor/resistor
>values for the PLL loop filter (going to the XFC pin) on the S12DP256.
>
>I am using a 4MHz crystal, and plan to use the PLL to generate the max bus
>frequency of 25MHz (50MHz PLL output). To do this I plan to use a value for
>REFDV of 3 and SYNR of 24.
>
>I cannot find any application notes on how to set the resistor and two
>capcitors (R0, Cs and Cp).
>
>If someone can point me in the direction of information to do this, or
>provide a calculation for me to use, that would be much appreciated.
>
>Regards,
>
>Adrian
>
>http://careers.yahoo.com.au - Yahoo! Careers
>
>- 1,000's of jobs waiting online for you! >-------------------- >
>">http://docs.yahoo.com/info/terms/




That is fantastic Gilles.

Just what I was after!!

Thanks,

Adrian

----- Original Message -----
From: "Gilles Blanquin" <>
To: <>
Sent: Friday, November 08, 2002 9:11 PM
Subject: Re: [68HC12] XFC Loopfilter C and R values >
> Hi Adrian.
>
> Found in this 68HC12 mailing list:
>
> A PLL components calculator program for the HCS12 is available on the
Nohau
> web site at:
>
> http://www.nohau.com/s12calc/pll_302.html
>
> Regards,
> Gilles > At 08:11 AM 11/8/2002, you wrote:
> >Hi All,
> >
> >Is anyone able to help me out with the setting of the Capacitor/resistor
> >values for the PLL loop filter (going to the XFC pin) on the S12DP256.
> >
> >I am using a 4MHz crystal, and plan to use the PLL to generate the max
bus
> >frequency of 25MHz (50MHz PLL output). To do this I plan to use a value
for
> >REFDV of 3 and SYNR of 24.
> >
> >I cannot find any application notes on how to set the resistor and two
> >capcitors (R0, Cs and Cp).
> >
> >If someone can point me in the direction of information to do this, or
> >provide a calculation for me to use, that would be much appreciated.
> >
> >Regards,
> >
> >Adrian
> >
> >http://careers.yahoo.com.au - Yahoo! Careers
> >
> >- 1,000's of jobs waiting online for you!
> >
> >
> >--------------------
> >
> >
> >
> >">http://docs.yahoo.com/info/terms/ > -------------------- >
> ">http://docs.yahoo.com/info/terms/
>

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