How to generate 10MHZ , square wave , ( from zero up to vcc ) , with very low jitter

[goldsmith]

Dear All
Hi
I want generate 10MHZ square wave ( without negative cycle ) with 50 percent duty cycle , and with lowest jitter , and rise time and fall time .and with amplitude about 5 volt .
So is it possible that you guide me to design it , please?
Best Regards and appreciates
Goldsmith

 

[mister_rf]

See this :
https://www.edaboard.com/threads/141168/
https://www.edaboard.com/threads/130847/


Timing, Clock Shaping

 

[goldsmith]

Dear mister_rf
Hi
Thank you for reply.
I have an idea here but as i know , relaxation , oscillators with not gates , hasn't 50 percent D.C , do you have any idea to improve it ?
Regards
Goldsmith

 

[RJM]

Start with 20MHZ, divide by 2 (flip-flop) = 10MHZ 50% duty cycle.

 

[goldsmith]

Dear RJM
Hi
Thank you for your reply .
But how can i start with 20MHZ ? my mean is , can you suggest me a 20MHZ square wave oscillator with good specifications , please?
Regards
Goldsmith

 

[RJM]

If you start with any 20MHZ square wave oscillator, no mater what the duty cycle, and pass it through an edge triggered flip-flop you will end up with a 10MHZ square wave with a perfect 50% duty cycle. Just use a crystal oscillator. To be even more accurate you could start with a 2560MHZ oscillator and use 8 bit prescaler Ic (divide by 256) to give you your 10MHZ, Although the RF layout would have to be more exacting.

 

[dselec]

! u can buy ready made quartz osc and add it to c mos ..ttl is better and then pass it thru Schmidt trigger
http://www.icbase.com/pdf/add/ti/AN-101-00039en.pdf

 

[RJM]

You could could start with one of these.

**broken link removed**

2% frequency accuracy. Or 20Mhz divide by 2 = 1%, Or 40Mhz divide by 4 = 0.5%

 

[goldsmith]

Thank you for all of your replies and helps . i'll try these ways , and will give you the result back !
Respectfully
Goldsmith