M
mrgizmo
- Jan 1, 1970
- 0
Which is the most popular? Is there a demo?
mrgizmo said:Which is the most popular? Is there a demo?
Which is the most popular? Is there a demo?
mrgizmo said:Which is the most popular? Is there a demo?
Which is the most popular? Is there a demo?
mrgizmo said:Which is the most popular? Is there a demo?
True. Mainly RF and digital till now though they become analog atKevin said:Well, with all due respect, you cant possible do much serious analogue
design.
Oh dear...Ever actualy tried to produce an analytical, closed form
solution for a 2 transister circuit, ac and transient? e.g.
http://www.anasoft.co.uk/EE/widlarlambert/widlarlambert.html
I wouldn't even consider trying to outdo a commercial opamp. I just buyI certainly see you have no idea at all.
Ok, a cheap bicmos process might cost $100k for the mask set, and 2
months fab time. Just what do you think the probability of getting a
1000 transistor circuit right first time? What about a 10,000 transistor
circuit?
It just aint goanna happen mate. Spice simulation is routinely used, 8
hours a day, 5 days a week by 1000's of analogue chip designers. Its the
only way to it today. Even then, concept to production can take a year.
There is simple too much to check out over all worst case operating
conditions and process corners to not use simulation. I don't really
know where to begin a description as there is so much that spice is used
for, that cant be done cost effectively with hand methods in today's
market. Its a never ending list. For example, amplifier stability,
temperature effects, pulse responses, etc...
What you need to do is actually try using spice to design say, a 50
transistor op-amp. Spend a few weeks doing this, then it should sink in
that you never want to go back to trying impossible hand calculations
again.
Sounding oldfashioned : what do you guys do with this
simulation software ? In my 20+ years in the field I never
had the need for them.
Mostly a few (+-*/log,exp) operations are sufficient.
Rene said:Sounding oldfashioned : what do you guys do with this
simulation software ? In my 20+ years in the field I never
had the need for them.
Paul said:(!) I'm staggered. Perhaps you're one of these people who actually
enjoys doing a colossal amount of time-consuming, complicated and
repetitive calculations. Most folk just want to get on with the design
itself!
Every engineer should have a PC with (LT is free ) Spice a schematic
capture Mathcad and board layout and router.
For quick prototypes mill the pcb directly from the PC to PCB material.
The biggest circuit I've ever built is only 0.2" on a side.
LTSpice isn't
compatible with my models,
the schematic capture isn't compatible with the
tools from Mentor, Cadence, Synopsis, or anyone else,
and board layout and
routing software can't begin to be used to design a chip.
I do have Mathcad, though, and find that to be very useful.
-- Mike --
Bill said:Depends what you mean by serious analog design.
correctly, I'm sure - that designing analog integrated circuits is
pretty much impossible without simulation.
The work I've done over the past thirty years included what looked
like fairly serious analogue design at the time, and involved
virtually no simulation software. I've not been designing analog
integrated circuits - obviously - but I've used a lot of them, and the
odd transistor where we needed speed or exponential/logarithmic
transfer functions.
Certainly not, and how often is it necessary?
Gilbert have already done it where it matters,