hspice measurement for switching time

[sbtauseef]

Hi,

I have a signal lets say V(RF). I am trying to calculate the on/off switching time. I know the start time when it start to switch, I know the end value. I have almost zero knowledge on hspice. My question(s) are:

1. How do I calculate the switching time? Can you please give me the expression
2. Are the measurements different for OFF or ON switching?

 

[dick_freebird]

First you define the measurement of "on" and "off"-ness. This
varies. You could use 50% of load voltage as a test method
for timing. Your customer's application might however be
concerned with "I said -off-, dammit!" like decaying to within
10% of settled "off" level (they want < 1% maybe, but accept
the limitations of automated testing SW/HW).

So you need to measure final value, initial value, figure the
test threshold voltage. That's .measure and math I reckon, not
being an HSPICE-dialect guy.

The input threshold, the same way.
Now you have levels figures, to do crossing-time measures.
Maybe this is measure with "find" or whatever (I am mostly
using ngspice these days, dialect may vary in the details).

It would be surprising / disappointing if your simulator online
documentation did not offer examples of event-time .measure
methods, it's one of the most popular "things to want to do".