super fast divide-by-N

[CBFalconer]

langwadt@ieee.org wrote:

Thomas Magma skrev:

.... snip ...

Ha. Let me give you a bit of back ground then. I am really pushed
for space. I need different clock frequencies thru-out my board.
My highest frequency is a Fox RFXO running around a GHz. I would
like to derive all other clocks from this one if possible. Next
lowest frequency is around 80 MHz. Then a few after that. I hate
PLLs and I don't want a bunch a xtals on my board. So I thought
I would just divide down from my highest frequency. One chip
solution would be the best.

I'd think that whenif you find something that will divide 1GHz to
80MHz, it'll be bigger more expensive and more trouble than just
adding a 80MHz oscillator ...

And you will find that syncing that with the 1 GHz clock is more
accurate than a countdown. There may be some 1 clock 1/2 period
jitter because there will be some sort of error in 80Mhz oscillator
wrt the 1 Ghz rate. The overall rate will be as accurate as the 80
Mhz oscillator. It also means you only need 1 D flip-flop that can
clock at 1 Ghz.

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