Design a frequency synthesizer (PLL)

[Eng.SAM]

Hi all, I hope u all fine and in a good health

I need to design a frequency synthesizer (PLL) with an output rage from 1KHz-30KHz, I google this bt I found a lot more complex circuits to design, so I hope u guys can help...

Thanks in advance
SAM

 

[mrmiller1]

Hi all, I hope u all fine and in a good health

I need to design a frequency synthesizer (PLL) with an output rage from 1KHz-30KHz, I google this bt I found a lot more complex circuits to design, so I hope u guys can help...

Thanks in advance
SAM

Sounds like you need a filter. I would design the process, come up with the transfer function and find the output frequencies. If your frequencies are off than throw in a filter with the correct transfer function.

 

[Eng.SAM]

Thanks man for ur replay, but I don' need afilter I need some frequency synthesizer, it's input will be any frequency, but the output is so important to be around 25 KHz.

There are types for frequency synthesizers:

Phased locked loop based synthesizer (PLL) which is easy to implement than other types.

Direct digetal synthesis (DDS), ...

so I hope you can help me with that...

Thanks in advance
SAM

 

[vk6kro]

As a minimum, you would need to know what size steps you need.

So, if it went 1000 Hz, 2000 Hz, 3000 Hz ... 30000 Hz in steps would that be OK?

Or, would you want it to be set in 1 Hz steps? So, 1000 Hz, 1001 Hz, etc?

 

[Eng.SAM]

I need a step size of 1KHz, since I'll use the freuencies 24.5, 25, 26.5

 

[vk6kro]

That would be steps of 500 Hz.

Are they the only frequencies you need? 24.5, 25, 26.5 ?

 

[Eng.SAM]

Thanks a lot, but I need the frequencies until 30khz ....

 

[berkeman]

Thanks a lot, but I need the frequencies until 30khz ....

So tell us how frequency synthesizers work. We will not do your school design project for you. Read this intro article, and ask us specific questions if you have them.

http://en.wikipedia.org/wiki/Frequency_synthesizer

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