Talk:Dual-modulus prescaler

Not a way to obtain fractional-N synthesis

This article contains a very common mistake: dual-modulus prescaler is not a way to obtain fractional-N synthesis. Since division ratios M,N and A are integer, overall division ratio is integer as well and hence low resolution due to prescaler M·f_ref may be made f_ref only. Hence a basic integer-N resolution (like in the case without prescaler) is obtained rather than true fractional synthesis.

Illustration in error

The right hand side of the prescaler (labeled /M or M+1) shows an output that is shorted with the VCO output. It should show the VCO output as the INPUT to the prescaler. PirateMonkey, can you fix? RastaKins (talk) 22:41, 6 March 2008 (UTC)

PirateMonkey's edit history shows that he or she hasn't been here since sometime in 2007. --Firefly322 (talk) 12:04, 13 August 2008 (UTC)

Fractional-N Correction

While it may be true that fractional-N synthesizers use dual-modulus prescalers, the contrary is not true. As outlined above, what you end up with is a plain integer-N relationship. DMP is simply a means to attain integer-N at high frequencies. I have adjusted the article to reflect this correction. I welcome any comments or questions directly. Cam Finnigan (talk) 02:40, 21 August 2008 (UTC)

Dual_modulus.png and formula

This image uses R for both dividers and the formula uses N for both. I have a modified image and changed the formula. How do I upload the image?

Rdvrey (talk) 08:31, 12 October 2009 (UTC)

Drawbacks

Doesn't this scheme have some drawbacks, like increased frequency jitter and/or phase jitter? I think those should be included in the article, if any. --Mortense (talk) 21:05, 6 March 2018 (UTC)