M
mikelinyoho
regards:
Does it make sense that to use HSPICE to simulate circuits if being a
hardware
engineer?.....
Does it make sense that to use HSPICE to simulate circuits if being a
hardware
engineer?.....
mikelinyoho said:Does it make sense that to use HSPICE to simulate circuits
if being a hardware engineer?.....
Two of the best analog guys who I know personally use SPICE for allmikelinyoho said:regards:
Does it make sense that to use HSPICE to simulate circuits if being a
hardware
engineer?.....
Two of the best analog guys who I know personally use SPICE for all
their circuits. Of course, there's a lot of expertise in simulating
a circuit _right_ and knowing what stimulus to give it and what types
of analysis to subject it to.
Tim Wescott wrote...
In my experience the most important often-overlooked aspect of Spice
analysis is bench-verifying the component models for accuracy. It's
amazing just how poor most manufacturer's spice models are, almost as
amazing as the blind trust placed in them by typical spice enthusiasts.
(1) The models I receive from semiconductor foundries
are VERY accurate.
Jim Thompson wrote...
Excepting, of course, for the MOSFET subthreshold region?
Jim Thompson said:On 21 Sep 2005 07:31:01 -0700, Winfield Hill
(1) The models I receive from semiconductor foundries are VERY
accurate. As another poster pointed out, some foundries will accept
your Spice simulation as proof their processing was flawed.
How does that work? "My simulations with your models indicate that the
circuit doesn't work, but we built it anyway, and it works fine. Please fix
your process." The opposite would appear to be just as problematic: "Here
are my simulation results. They show that the circuit works fine. Please
review the results and fix your process."
-- Mike --
I've already demonstrated that FOUNDRY MICROCHIP models DO include the
subthreshold region.
sure it does!
Let the computer make the calculations, so you can concentrate on the
real "engieering"
I was in a presentation by a colleague that showed that even our
super-threshold models worked remarkably well in the sub-threshold region.
The modeling folks musta made a mistake. ;-)
They're probably fit by a computer program, so that, even with
non-sub-threshold data, the curvature pretty well lines things up.
Jim Thompson wrote...
Over what current range? I've posted real data over six orders of
magnitude, showing failures over all but the top two decades, but I
have yet to see any real *bench* data validating the putative "work
remarkably well" models. Remember, it's easy to make empty claims.
Moreover, keep in mind I'm not simply a nay-sayer: I've also posted
modified models that do work, plus links to literature for the same.
As for real-world uses for this kind of data and model performance,
try LDO regulators at low currents, if you aren't willing to accept
audio amplifiers at crossover. OK, sure, that's not important.
What's important is that the poor folks in Houston can't get out.
Looks like most everyone can't get out. How do you move a few
million people on short notice?
Jim Thompson wrote...
Exactly. I suppose now you're a bit more understanding about
the difficulties New Orleans faced in fully evacuating before
the storm? Not that either city should be excused from having
workable plans, of course.
But, not to worry, George will be
there tomorrow to clear out stalled traffic. Such a relief.