On Sep 18, 2007, at 12:07 PM, al davis wrote: > So, for LT-spice .... > > What is the "organic matter" being added to the soil? > What are the "beneficial insects?" > > And finally: > What are the "weeds" they want to choke out?
These are interesting questions. The answer is that LTC's business is selling chips, and by providing a tool that does very fast and very accurate simulations of their parts, they increase the chance that an engineer will choose an LTC part over a competitor's device. After all, switchmode power supplies can be tricky and an accurate simulation gives one a warm- fuzzy feeling that at least the topology and the component selection are correct. Their reason for not opening the format is simple: if one could use LTSpice to simulate a TI or National or whoever's part, then obviously the engineer could choose the competition as easily as choosing the LT part, and THAT is not in LT's interests. Linear Technology supports LTSpice as a means to an end. It would be nice if LT had standard spice models for their switchers that one could use in another program, even if these models were slower than the proprietary models. They DO provide spice models for their amplifiers, comparators and linear regulators, but clearly they think their switchers are the crown jewels. -a _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user