RE : [spectrumanalyzer] about C27 and R12 on PLO 2

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RE : [spectrumanalyzer] about C27 and R12 on PLO 2

Post by Marc OLANIE » Tue Dec 06, 2011 9:21 pm

Attachments :[/list]Thanks Scotty.

Everything's clear now :-)


A good working kernel is not supposed to crash unless it says "please"

(traduction : Da Power, Fantudjûû ! RuleZ Tartiflette !)


De: [ t=_blank][/url] de la part de william sprowls

Date: mar. 06/12/2011 23:17

À: [ t=_blank][/url]

Objet : Re: [spectrumanalyzer] about C27 and R12 on PLO 2

Hi Marc,

The original reason to delete C27 and R12 on all PLO modules was for power conservation and phase noise minimization. It does this.

However, during testing, I found that PLO1 and PLO3 harmonic and spurious was decreased a little with the components re-installed. It was not a big decrease, but enough to justify the re-installation. I could find no difference with or without in PLO2. Therefore, leave them out of PLO 2


--- On Tue, 12/6/11, marcolanie wrote:

From: marcolanie

Subject: [spectrumanalyzer] about C27 and R12 on PLO 2

To: [ t=_blank][/url]

Date: Tuesday, December 6, 2011, 1:14 PM


The MSA documentation insists on the fact that C27 and R12 must be kept for PL0 1 ans PLO3. The chapter covering PLO2 operation says

"omit C27 and R12. The driver to this circuit will absorb the mismatch reflection. This may seem a like poor design but it is valid. It improves the noise performance of the PLL."

Is this sentence "up to date" or is it a fossil noise from a former modifications ? Should I keep C27 and R12 on PLO2 ?

Thanks in advance

Marc (lost in translation ;-o )

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