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Re: .savebias command commented out
g.moberg
Hello Again,
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Just to finish this topic out, today I generated the "Skip" file successfully. Since this is an SMPS circuit whose inductor currents are not zero, I edited the "Skip" file to change its .nodeset command to a .ic command, and set the initial conditions of the 2 inductors to their approximate values at the time the .savebias command executed. This changes the inductor characteristics for initial convergence from short circuits to ideal current sources with the specified initial conditions. This must be done to prevent the circuit from converging to a highly erroneous state with 0V across the inductors. The simulation picked up very close to where I expected it to, and settled quickly so I can do the load transient analysis without waiting minutes to get to a settled condition. Thanks again for those who looked at this. Greg Moberg --- In LTspice@..., "g.moberg" <gregory.moberg@...> wrote:
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Re: AD8336 failure
Tony,
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You are right about the path - I messed up, sorry. I will follow the check box suggestion from now on. Thanks again, STM --- In LTspice@..., "Tony Casey" <tony@...> wrote:
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Re: AD8336 failure
I opened the AD8336.asy you had in the zip file with FILE OPEN in LTspice but I don't find any attributes.
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When I open it in notepad the only attributes are pin references. Version 4 SymbolType BLOCK RECTANGLE Normal -80 -104 80 104 WINDOW 0 0 -104 Bottom 2 WINDOW 3 0 104 Top 2 SYMATTR Value AD8336 SYMATTR Prefix X SYMATTR SpiceModel ad8336.cir SYMATTR Value2 AD8336 PIN -80 -64 LEFT 8 PINATTR PinName GNEG PINATTR SpiceOrder 1 PIN -80 -32 LEFT 8 etc. How do I open the others to see what you set? Thanks, STM --- In LTspice@..., "Helmut" <helmutsennewald@...> wrote:
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Re: AD8336 failure
--- In LTspice@..., "stm6823@..." <stevemorris@...> wrote:
Hello STM, I made a specific symbol which isn't editable. All symbol of the LTC-opamps are made this way. Please open the symbol(.asy) with LTspice to see which attributes I have set. Best regards, Helmut |
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Re: About impedance
Tony,
While LTspice may not be the ideal tool for RF design, it can still be quite useful. You are correct that it does not have native support for producing a Smith chart. However, some clever contributor to this group has provided a means to plot the graticule of a Smth chart and impedance curves with frequency markers (Files > Examples > Apps > SmithLTspice.zip). ? With respect to LTspice handling s-parameters, it certainly can. The .NET command computes network parameters in an AC sweep. The HELP files says in part, ? "This statement is used with a small signal(.AC) analysis to compute the input and output admittance, impedance, Y-parameters, Z-parameters, H-parameters, and S-parameters of a 2-port network. It can also be used to compute the input admittance and impedance of a 1-port network. This must be used with a .AC statement, which determines the frequency sweep of the network analysis." ? There is an entire section in the tutorial section of this groups files devoted to s-parameters in LTspice (Files> Tut> S-Parameter). ? All the best, ? ?? - Philip ________________________________ From: Tony Casey <tony@...> To: LTspice@... Sent: Thu, September 15, 2011 8:55:18 AM Subject: [LTspice] Re: About impedance ? --- In LTspice@..., "keantoken" <keantoken@...> wrote: Hello Keantoken, If you're doing RF design, on oscillators, for example, it is essential to be able to see both real and imaginary parts clearly and separately without having to do mental arithmetic for each frequency displayed. The Cartesian presentation shows this much better for most people, although a few will claim they can glean everything they need from a polar plot. But then some people are able to write a complete GUI in one line of C. For doing serious RF design, LTspice is not the ideal tool, since it does not have native Smith chart and cannot handle S-parameters, but it is at least possible. Regards, Tony [Non-text portions of this message have been removed] |
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Re: Hey i am working on a Class D amp project, need help about LT Spice
Tony Casey
--- In LTspice@..., "cukkacan" <mustafa_cukka@...> wrote:
Hello, I don't know which web you checked, but there are thousands of links relating to class D amplifiers, many of them on the semiconductor manufacturers' websites, check there first. In general, you will only find people here keen to help once you have demonstrated a willingness to try. Start but drawing a schematic, try to make it work, then ask for help when it doesn't. So far, there's no evidence that you have done anything at all. Regards, Tony |
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Re: AD8336 failure
Helmut,
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Thank you very much for your time and help. So much for me to learn. I integrated all your schematic changes into mine and it works great. I put the changes in one at a time to observe the effect. Lots of subtle stuff like the series resistance in the supplies messing things up that I don't get. I am curious about your reference to correcting the symbol because I am still using mine and it works OK. I had LTspice make it from the netlist editor. I tried to open yours to see what you changed but it is not editable. What did you change? Thanks again, STM --- In LTspice@..., "Helmut" <helmutsennewald@...> wrote:
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Re: About impedance
Tony Casey
--- In LTspice@..., "keantoken" <keantoken@...> wrote:
Hello Keantoken, If you're doing RF design, on oscillators, for example, it is essential to be able to see both real and imaginary parts clearly and separately without having to do mental arithmetic for each frequency displayed. The Cartesian presentation shows this much better for most people, although a few will claim they can glean everything they need from a polar plot. But then some people are able to write a complete GUI in one line of C. For doing serious RF design, LTspice is not the ideal tool, since it does not have native Smith chart and cannot handle S-parameters, but it is at least possible. Regards, Tony |
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Re: AD8336 failure
Tony Casey
--- In LTspice@..., "stm6823@..." <stevemorris@...> wrote:
Hello STM, It's possible I looked before the files were actually there, but when I found them they were in Files>Temp>AD8336, not Files>AD8336. It's also helpful when uploading files, to check the box about making an announcement to the group with a comment, not least because that message will have the correct hyperlink to the uploaded file because it's autogenerated and not prone to user error. I'm glad Helmut sorted you out, though, as he usually does when others fail. Regards, Tony |
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Re: Simple model for diffin-diffout amp
ehydra
Indeed, and that is the reason why I just use the datasheet and the universalopamp symbol to get rid of the problems. Most times the universalopamp makes a better job.
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- Henry -- ehydra.dyndns.info RobertTalty schrieb: The Microchip opamp spic models are very complex and attempt to model all types of errors and their Temp variations, but in the end these models cause convergence problems, so what is the point of a complex model that causes beginners convergence problems. Convergence can be hard for experienced spice users to solve, so it is the last thing that beginners need. |
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Re: AD8336 failure
Tony,
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Thanks for answering. I thought FILES\AD8336 in my help request would indicate where all the files were. Is there another way I should have done it? STM --- In LTspice@..., "Tony Casey" <tony@...> wrote:
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Re: adding noise to the model of a sensor
--- In LTspice@..., "Helmut" <helmutsennewald@...> wrote:
Thank you, noisegen.asc + noisegen.asy is what I needed! Ruggero |
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Re: About impedance
Dear Helmut,
? Thank you very much for your quick response. Yes, I was doing .AC simulation. ? Sincerely, ? Mahmudul Kabir, Japan? --- In LTspice@..., Mahmudul Kabir <nilonjana@...> wrote: Hello Mahmudul Kabir, I assume you use .AC simulation. In this case you can plot in Cartesian format which shows the real part with a solid line and the imaginary part with a dashed line. Best regards, Helmut [Non-text portions of this message have been removed] |
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Re: Hey i am working on a Class D amp project, need help about LT Spice
John Woodgate
In message <j4sde1+lkfq@...>, dated Thu, 15 Sep 2011, cukkacan <mustafa_cukka@...> writes:
Hey, i am sophomore at the university, and i have a circuit sketch and data sheet. However, i dont know how to use LT Spice effectively. i couldnt build the circuit on LT Spice perfectly. Could you help me about this issue ?Study the examples and tutorials available on the list's web site. Read the Help. Upload your non-working schematic to the web site Files -> Temp and tell us you've done it. This list is not a general design help list. A web search for 'Class D' will provide you with hundreds of good hits (and some bad ones, but you can't win them all). -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK When I point to a star, please look at the star, not my finger. The star will be more interesting. |
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Re: About impedance
--- In LTspice@..., Mahmudul Kabir <nilonjana@...> wrote:
Hello Mahmudul Kabir, I assume you use .AC simulation. In this case you can plot in Cartesian format which shows the real part with a solid line and the imaginary part with a dashed line. Best regards, Helmut |
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Re: adding noise to the model of a sensor
--- In LTspice@..., "rug_rossi" <rrossi@...> wrote:
Hello Ruggero, The 1/f noise is implemented in diodes. Thus diode noise may be the natural choice for an 1/f noise source. Files > Tut > noisegen Files > Tut > noisegen_with_subcircuits Files > Tut > new_diode_noise.asc You already mentioned the "universalopamp". It contains parameters en and enk to set noise value and corner frequency. Best regards, Helmut |
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About impedance
Dear Members,
? Is there any chance to calculate of real or imaginary part of impedance while doing a simulation?with any AC voltage? ? Or is it possible to draw?a trace of real part or imaginary part of impedace in LTspice? ? Thank you in advance, ? Mahmudul Kabir, Japan ? [Non-text portions of this message have been removed] |
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