Integer-N vs Fractional PLL [hlp]

[elec350]

hello
which is better? integer-N or fractional PLL?

 

[khouly]

it will depend on the application. and channel spacing and BW requirements of the PLL. in some cases the design requirements forces u to use the fractional N which is more compalex and need Sigma Delta modulators and so on

so it will depend on ur requirements

khouly

 

[elec350]

hello
khouly wrote:

it will depend on the application. and channel spacing and BW requirements of the PLL. in some cases the design requirements forces u to use the fractional N which is more compalex and need Sigma Delta modulators and so on

so it will depend on ur requirements

khouly

pls explain more? Is programming of a fractional PLL IC more complex than an integer-N PLL?

 

[khouly]

the design is more hard , the programing is not a big deal

if u have 2 IC's one integer and the other is fractional it will be simple to use any one of them

the main problem is in the design the PLL chip

Khouly

 

[jecyhale]

hello
which is better? integer-N or fractional PLL?

there must be a fixed reference frequency for integer-N PLL,
While the fractional-N PLL can work with more reference.
So I think the reference frequency is the factor which detemines you choise.