Re: Wanted: LM-709 (Spice model) National Op-Amp


Paul Rako wrote:

> Well, it was an LT guy that told me LT-SPICE was a PSPICE variant
> but I don't have the need to trash people [...]

[cut thinly veiled trashing of various people]

> Several years ago EDN magazine did a circuit and gave it to 6 SPICE
> vendors and Jim Williams at Linear Tech. If I remember about half
> of the programs failed to converge and the rest gave wrong results,
> sometimes wildly wrong compared to Jim's real board. Was there a
> memo I missed? Have models and SPICE engines gotten that much
> better?

LTspice has improved models for inductors and capacitors that allow
realistic parasitics to be entered and computed as an integral part
of the element. This prevents the corresponding branch admittances
from going to zero or infinity for reduced time steps during a
transient analysis, greatly improving run time convergence.

I doubt you or anyone else has a legitimate circuit that would
trip up LTspice.

> Can anyone really get any kind of mid-range SPICE to deal with
> non-linear magnetics?

LTspice can without breaking a sweat. Download the program and
read the help file topic on L devices.

Regards -- analog
.