26 Dec
2004
26 Dec
'04
12:17 p.m.
Tony Duell wrote:
I would guess it's considerably less accurate than a crystal, and a bit
less stable (although not too bad). I wouldn't want to use one, for
example, as the reference for a real time clock.
One advantage of the delay line approach is that you can get several
clocks offset from each other by know time delays (one from each tap of
the line). This is probably why DEC used it in the 11/34
A delay line is what the name implies. A component that delays a signal,
here a digital signal. If the input changes, then the output changes a
certain time (here 150ns) later.
How precise is it? Is it comparable to a crystal oscillator regarding
stability and accuracy? The reason for multiple outputs (often called
'taps' is that you can get
signals delayed by different amounts. A 150ns delay line may have 5 taps,
say, 30ns apart. If the input changes, the first tap changes after
30ns,the next after 60ns, etc.
Are these typically linear distributed? I mean: are the time differences
between the taps always the same?