--- In LTspice@..., Panama Mike <panamatex@y...> wrote:
Dale wrote:
Mike, this sounds like something I'd like to
dissuade you from.
Helmult wrote:
I fully agree with you. The biggest advantage
of all the opamp models
[...]
The provided SPICE models should be also optimized
for good convergence in the simulation. If a model
doesn't provide some features like noise modeling
(.AC), it should behave more like an ideal
component in such a type of simulation.
The problem is that the PSpice models often don't
converge very well and don't model noise correctly.
That has nothing to do with Linear's opamp models,
it's common to most Boyle style models.
Hello Mike,
I have never said here that it is specific for LT models. My
statement has been a general one for all vendor's models.
If it is true that the Boyle model is so weak, why not starting with
another SPICE model? I am shure that LT has the right people(you for
example) to make excellent models.
They don't
converge well in PSpice either. It's just a really
lame modeling methodology. Sometimes I honestly
get the impression that SPICE macromodeling
engineers tweak a model until it doesn't run anymore
and pronounce it done at that point, blaming any
convergence problems are due to the simulator.
I have experimented with my own generic opamp model and indeed it
converges very different depending on the choosen circuit.
LTSPICE has been greatly improved over the last year regarding
convergence problems. Most of the problems seem to be history.
Of course the advantage of being able to run
them in PSpice is important.
There are even more SPICE simulators around. Some of them are
specific SPICE simulators like ICAP and others are part of PCB-CAD
packages. All these users need/want SPICE models of LT opamps.
Finally I hope that LT always provide opamp models for the whole
SPICE "family" too.
Best Regards
Helmut
