[sdiy] measuring pulse width with ns accuracy...

[Bert Schiettecatte]

hi all,

i'm trying to find a way to measure phase difference 
between 2 clock signals. They have a phase difference 
anywhere between 3ns and 10ns. I thought about OR-ing 
these 2 signals and then using the result to charge 
a capacitor. I could then measure the voltage across 
the cap. Does anybody here have any idea if this will 
work? If yes, are there certain recommendations you could
give me concerning what OR gate to use (I suppose the 
one with the shortest propagation delay I can find...) 
and what capacitor type and size?

Thanks,
bert