Well, its a very good idea NOT to use inductors unless they are actually needed. They can cause convergence issues. Even in the expensive Cadence Spectre RF, I am currently having to put clamps across inductors for PSS simulations in order to get it them work. Inductors like to generate MVs whilst the answer is being iterated out.
Kevin Aylward B.Sc.
That's an all-pass to model the OpAmp excess phase... and it is low-Q, so I don't think it'll ever be an issue in this application.
As for your inductor problems... you just need to use TANH >:-} ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
Its one of those probability things.
LC circuits like to ring. Just putting in one inductor can make the time steps multiply up to cause slower simulation. So, son, when you have the experience I have, you learn to look out for those little subtleties...
Kevin Aylward B.Sc.
Son? Unless you're 94+, there's no way "son" applies ;-)
By low-Q, like Q~1, so I'm safe.
Inductor in a switcher, that's another animal altogether.
But I will take your advice and create a part "L-bounded", at-the-ready in case I have a problem >:-} ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
The embedded spaces in the full path file names are causing problems. They need to be placed in quote characters("). There may be other issues as well.
?-)
LTSpice should handle this potential issue no problem because it has inherent dampers in its two terminal, multi-element models for Ls and Cs. I am not aware of any other spice having such a facility. Cadence Spectre does not, and it is a major blemish for such a "high end" simulator.
Kevin Aylward B.Sc.
I had occasion, the first three months of this year, to have to use my least favorite simulation tool, Cadence Virtuoso and derivatives... what a royal pile of CAD-doo-doo!
How they get away with selling such an inadequate tool I'll never know... though I suspect they con _clueless_management_ into thinking that you need their whole CAD suite to properly design, layout and fab a chip... which is pure baloney... I have ~70 functioning chips, designed in PSpice (MicroSim) Schematics, then laid out with IC Editor... LVS is no sweat... I can match the layout netlist requirements of _any_ layout tool.
Back to the inductor... a TANH G-source across the inductor with adjustable voltage limits (in both directions) should do the trick ;-) ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
Well... I am still a huge supporter of Cadence and its whole tool flow, despite its blemishes. I wouldn't want to use anything else. Its environment and facilities are still orders above PSpice. There is just so much you can do that just isn't in the more "schoolboy" tools. I don't consider PSpice a professional level ASIC design tool, despite someone's ability to work around its deficiencies for ASIC design.
I don't agree that management is conned. I had to personally fight very hard when I started my current job to get Simetrix ditched and Cadence brought in. Its a no contest.
Note that even 100 Mohms across the inductance of a xtal can kill its oscillation.
Kevin Aylward B.Sc.
Name something Cadence can do that I can't with PSpice (other than PSpice doesn't do layout >:-}
Name a deficiency.
[Keep in mind that I am definitely yanking your chain... over the years I've written many "scripts" (Algebraic mostly, some IF,THEN,ELSE) so that I can even do binning automatically in PSpice :-]
I've not had any run-away inductors, so I think it must be a Cadence issue.
...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
Well, for one its a bloody 1G download, which I have just done to see whether or not my considerations are valid. I haven't use PSpice for over 10 years.
I will give it a look over. It doesn't look like it can install in Program Files. I pressed the install, and now notice it installed in C:\ This is pretty much unacceptable for seconds. Assuming, as it looks, that everything is installed there, and that only one of those files gets modified by the program, it wont run as it should if installed in program files.
Does it have an equivalent to Cadences "view switch"? That is, the ability to to switch with one change what set of schematics is actually attached to their symbols?
Spent 15 mins so far, and cant even get an example schematic displayed.
This is a physical reality issue. XTAL oscillator wont oscillate if damping resistance is "significant". A c1 of 10ff @ 50Mhz is an inductance of 1mH, which is an impedance of 300k. So care need to be taken on any clamps.
Kevin Aylward B.Sc. snipped-for-privacy@kevinaylward.co.uk
I have a licensed copy on DVD ;-)
I tend to be the rebel without a cause... where I can I install OUTSIDE of Program Files... I hate Wimpows with a purple passion >:-}
No. But I assign sub-schematics to a BLOCK, not a symbol... symbols for schematics is a Cadence hair-up-butt-nonsensical usage.
You're not used to PSpice any more than I am to Virtuoso.
...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
Cs.
Spectre
fab
flow,
you
over 10
Program
everything
the
Non-issue. Lotus notes did not install in "Program Files" long after the issues were solved simply because it was not needed, the install in C:\Notes worked too well to bother changing it.
ability
to
Is that something like the standard hierarchal view that many tools provide?
Silly comment. Some 20 years ago i had to learn Microstation out of books. It was about 3 days to get enough down to get basic functionality working and about 3 months to get to basic proficiency. Ecpecting to learn an equally complex program in 15 minutes is inappropriate.
The limiter was never intended to be applied indiscriminately. More as an enhancement to discreet inductor models, rather than the model inductances inside an electromechanical resonator device.
damping
1mH,Aleady addressed.
Not sure what you mean here. Other post explains its use.
PSpice "Schematics", might be better, unfortunately I get a "no SPB16.6 Installation found" when I try and install it.
My comment is for the Orcad interface.
So, far its getting even deeper into shit. Double clicking on a component to view/set its properties switches to a new full normal page tabbed window instead of a small dialog box. This is insane.
Horizontal scroll - the lord wept...There is none, unless you scrunch up the main window. You just cant re-center the schematic horizontally to where you want it to go.
It doesn't look like it can do orthogonal rubberband. SuperSpice doesn't either, but its cheap.
Test points are hilarious. I like the option (in SS) to move test point off a wire to a blank piece of page to remove a signal trace. Orcad pops up a bloody dialog box and tells you the marker will be ignored, then puts it back where it came from, and the trace stays.
PSpice output display. Basic features missing. You need to press the zoom area button then mouse zoom, rather than just mouse zoom immediately.
Moving the mouse over the waveforms produces an X-Y readout that is useless. The mouse should lock on to the actual waveform trace like in Cadence or SuperSpice. I find this feature absolutely indispensible. Its a bread and butter feature.
I have still to figure out if it can support multiusers on the same project, in a manner equivalent to Cadence, which is indispensible for serious development as well.
Kevin Aylward B.Sc.
Its fingers nails down the blackboard. Programs/Software writers should know how to write programs that correctly use the operating system.
The Program Files and Program Data directories are a good idea, and most competent programs use them correctly.
No. View switches are indispensible for doing full chip design. One key function is that it allows all the lowest level transistor level schematic to be switched with a behavioural version allowing 1000 times faster functional simulations of the full chip, but still using full pin for pin and routing matching.
Nonsense.
Erhammm... well... I do know a tad about simulation, er.. hint: SuperSpice.
A program should not be complex to use, irrespective of internal complexity.
If a *schematic* *program* loads in its project file, it is absolutely nonsensical that the *schematic* does not get immediately displayed. The "Schematic" folder is not even visible in its file trees until "Design Resources is opened". The schematic is the driver.
Kevin Aylward B.Sc.
In PSpice (MicroSim) Schematics you just click on "draw block", draw a block and "push" into a sub-schematic, "pop" to return... no effort to draw a symbol required. If you've already labeled ports for the sub-schematic, they're automatically added as connections/ports on the block.
OrCAD _Capture_ should be called _Crapture_ ;-)
It's OrCAD _Capture_, what can I say?
In PSpice (MicroSim) Schematics, I hold down right mouse button and drag the view to wherever I want.
It's OrCAD _Capture_, what can I say?
It's OrCAD _Capture_, what can I say?
Poor baby ;-)
What's "multi-user"? I design whole chips single-handedly (except for the digital buses), as in this one (now well-beyond NDA restrictions)...
...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
And how many copies SuperSpice have you sold ?>:-} And how many copies of LTspice and PSpice are in use? ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
The number of users of LTSpice is completely meaningless as to its real value. Its FREE. There is hardly any chance that LTSpice would have made it as a paid product. Its GUI is way too pedestrian. Yeah, I am sure, after the fact a few of the million un-paying users might claim that they would have paid $100 as its impossible not to think about pink elephants.
PSpice was good in its day relative to what was there, but I doubt if it sells many today, because of all the freebies and much cheaper stuff out there. As far as I'm aware, Orcad pretty much died for PCB design.
Kevin Aylward B.Sc.
Ok, but not related to view switching. As noted in the other post, a symbol can be simultaneously attached to schematics, verilog, vhdl, behavioural files etc. This allows various combinations of simulations to be run. e.g. switching between a real schematic and a Verilog version, noting that most digital logic in a mixed mode design is all done in code.
What's "multi-user"? I design whole chips single-handedly (except for the digital buses), as in this one (now well-beyond NDA restrictions)...
You are an exception...
ASIC design is done in teams. It needs a common database and environment where all can work (and view) on different schematics and layouts of the same project all at the same time, with appropriate automatic file locking.
Kevin Aylward B.Sc.
Then i guess you don't use Windows much on that level :)
Jamie
over
is
the
the
know
ability
attached
schematic
pin
displayed.
functionality
SuperSpice.
complexity.
I am mighty sure that JT does not have that experience because he does NOT use what he calls it "Crapture". Please try the tools he actually uses for a fair comparison. If i thought i could get a copy of his tools from him i would be at his place mighty fast.
?-)
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.