dick_freebird
Advanced Member level 7
I have the good fortune to be trying to simulate some
"digital" circuits in a fairly old 40V bipolar technology. The
only models I have are for a near-minimum transistor in
Mextram form.
Now I've been searching for info on how to model saturation
recovery time and coming up empty. This is probably the
most important, as well as most variable and most design
sensitive aspect of digital switching and there's nothing in
the docs I can find. At least the "good old" models gave
you a TR param you could jack around. It seems like the
Mextram model is maybe meant to be for "advanced" (RF,
CML, ECL) type circuits and you're just assumed not to
be saturating. There are some tau type params in the
Mextram model but they're set crazy low based on what I
recall from designing in 40V processes for many years.
Has anyone ever seen a decent discussion or document
on modeling the "hard-saturated" to "off" transition using
Mextram models? Base storage time fitting to data?
"digital" circuits in a fairly old 40V bipolar technology. The
only models I have are for a near-minimum transistor in
Mextram form.
Now I've been searching for info on how to model saturation
recovery time and coming up empty. This is probably the
most important, as well as most variable and most design
sensitive aspect of digital switching and there's nothing in
the docs I can find. At least the "good old" models gave
you a TR param you could jack around. It seems like the
Mextram model is maybe meant to be for "advanced" (RF,
CML, ECL) type circuits and you're just assumed not to
be saturating. There are some tau type params in the
Mextram model but they're set crazy low based on what I
recall from designing in 40V processes for many years.
Has anyone ever seen a decent discussion or document
on modeling the "hard-saturated" to "off" transition using
Mextram models? Base storage time fitting to data?
