12 Dec
2001
12 Dec
'01
3:26 p.m.
For coax or twisted pair the delay per unit length is given by:-
Delay (Secs/unit length) = Root( (C/unit length)*(L/unit length) )
Example: For RG58-U coax, C=100pF/m and L=250nH/m
Delay = root(250E-9*100E-12) = 5E-9 sec/m or 5ns/m
A pulse will travel 66% slower in RG-58 cable than free space.
If anyone needs to lay out high speed PCB's
the following book is highly recommended:
"High Speed Digital Design - A Handbook of Black Magic"
Howard W Johnson and Martin Graham
ISBN 0-13-395724-1
Chris Leyson