use HSPICE to simulate circuits if being a hardware engineer?.....

It works great for me because I'm only a simulation of a simulated engineer.

How about you?

Tim.

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.

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. As another poster pointed out, some foundries will accept your Spice simulation as proof their processing was flawed.

(2) But otherwise I roll my own (except BJT's, they're pretty accurate, AND easy to model ;-)

...Jim Thompson

Excepting, of course, for the MOSFET subthreshold region?

I've already demonstrated that FOUNDRY MICROCHIP models DO include the subthreshold region.

The discrete houses (power MOSFET's) have not bothered to model that region.

When I get a spare moment (when hell freezes over :) I'll fit a Level=7 model to your data to prove the point.

What you need to do is convince the discrete houses that modeling that region is useful to more people than just you ;-)

...Jim Thompson

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 --

sure it does!

Let the computer make the calculations, so you can concentrate on the real "engieering"

Roberto

----------------------- There are only 10 types of people in the world: those who understand binary and those who don't.

It's even more simplistic. If process test devices (generally five points on the wafer) fall outside the foundry-provided worst-case device models, the wafer can be rejected at foundry expense.

...Jim Thompson

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

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.

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. ;-)

That's fine, as far as it goes. I've seen people (folks here have too) arguing that the models are correct, even though they produce unrealizable results. At least in this universe, 'C' isn't negotiable.

Real men don't use Level=1 or Level=3 models ;-) That's the missing link to your understanding.

Real men also don't use power MOS devices for audio outputs... you've read the discussions here... they use tooobz ;-)

Looks like most everyone can't get out. How do you move a few million people on short notice?

...Jim Thompson

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.

Parking buses is a real plan? The population difference is also almost an order of magnitude different... #4 city versus #32... a whole lot less people to move from N'Orleans.

Always one for the SNIDE remark aren't we ?:-)

...Jim Thompson