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Uploading Models - Love some help with one.
Business Kid
I am uploading 2 HEMT models which I am using for the benefit of others. The ATF34143: And the single supply ATF54143. They contain nothing that I haven't garnered from? Avagotech's site and I don't view them as intellectual property of mine. They may help others trying to work with these unusual devices. Their status is: ATF34143: Fully an Avagotech model. tried only briefly. ATF54143. Slightly iffy. The drain/source seems to model well, in line with my hardware prototype.? The gate models well, but shows strange voltages with a source resistor in circuit. To be specific, +0.6V should be across the gate with the device midway on. But Add a 10 ohm source resistor and it's possible to see negative voltages on the gate. Instead of being stepped UP by about 0.5V (lost across the resistor) it seems to be stepped DOWN, i.e. negative. So LTspice models it with the gate more negative than the source (where it should be off) but it isn't off. This was taken from the ATF34143 and adjusted (imperfectly, I guess) from the datasheet simulation figures. |
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Re: VCO tuning curve
Many thanks Helmut. Your answer helped me a lot. On Thursday, December 19, 2013 1:58 PM, "helmutsennewald@..." <helmutsennewald@...> wrote:
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Hello Ahmed, You could use .step and .MEASURE commands to get the frequency versus voltage. The results of MEASURE will be saved in the errorlog-file(.log). Then right mouse click in this file to plot the results. Examples with MEASURE are available in the Files-section of this
group. All Files > Tut > Measure http://groups.yahoo.com/neo/groups/LTspice/files/%20Tut/MEASURE/TRAN/ Best regards, Helmut |
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Re: VCO tuning curve
Hello Ahmed, You could use .step and .MEASURE commands to get the frequency versus voltage. The results of MEASURE will be saved in the errorlog-file(.log). Then right mouse click in this file to plot the results. Examples with MEASURE are available in the Files-section of this group. All Files > Tut > Measure http://groups.yahoo.com/neo/groups/LTspice/files/%20Tut/MEASURE/TRAN/ Best regards, Helmut |
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Re: Membership renewal problem ....
+1 for phishing scam. Send a copy of the email to yahoo help, subject 'phishing email' or 'spoof email' ? No Internet set-up needs a 'phone number that I've heard of, and no don't give out your 'phone numbers on the net, unless you like receiving lots of cold calling type calls?:D ? Ditto e-mail addresses, or have one specially set up, if you must supply one, to get all the junk stuff ? HTH ? |
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LTSpice FFT resolution
Hello all,
What is the theory behind selecting the right max time step for FFT analysis? I always assumed that the max time step should be selected depending on the highest frequency resolution one might desire from the FFT. However, I noticed that I need to further reduce the max time step to avoid artifacts which appear as higher order harmonics. To analyse a simple audio circuit, I typically use a 1 kHz sine input signal, run a? transient (duration = 300 ms, max time step = 10 us). I checked my simulation setup with a simple circuit (2 voltage sources in series with a resistor, 1st source 1 kHz and second source 4 kHz). I observed that I have to reduce the max time step to at least 2 us in order to keep the artifacts below 130 dB. I would be very interested to better understand the theory behind! Thank you in advance, Jos |
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Re: LTspice Install problem under linux
Business Kid
> I have never EVER gotten the LTSpice web update to work in Linux,
in any It's the sort of thing I wouldn't try, as that was a great way to clog up a registry with junk, and end up with random files on your drive. Windows has got less inefficient, but old habits die hard.> distribution. It may have worked a long time ago, but I just download the new >.exe when I want to update. > On 18 December 2013 20:45, martin562284 <martin.sadler@...> wrote:
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Re: Membership renewal problem ....
martin562284
This sounds more like a phishing scam. I can't recall ever being asked to renew my membership to any Yahoo groups - some have lay dormant for many years but I can still access them.
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There is an apparent contradiction in your message below - you state that you are not a member and yet you are able to post a message - more evidence that the e-mail I presume you received purporting to be from Yahoo is in fact a phishing scam. --- In LTspice@..., Peter Kapas <pkapas@...> wrote:
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Re: I don't remember the procedure...
¿ªÔÆÌåÓýHi Vlad,
Thank you for your quick reply. The "tip" is the Ctrl-right-click to be able to rename with a "X" ! All is running 100% now. Best regards and a Merry Christmas, Rudi On 18.12.2013 17:56, imbvlad@... wrote: ?
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Re: LTspice Install problem under linux
martin562284
It's always worked fine for me - various versions of Ubuntu and Mint
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--- In LTspice@..., <keantoken@...> wrote:
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Re: CIC unstable output
I tried various settings for reltol, abstol, gmin, etc, but nothing seems to give better results, on the contrary. I also tried removing the gain at the input and using integrators with 1/M/R gain which would make the whole system work with values ranging from volts to hundred(s, at most) of volts, thus no longer a threat to the matrix solver; nothing. I tried adding B-sources as delay() replacements for tlines, it's worse. Currently, I am out of ideas. If any of you have some, please share them. Vlad |
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Re: I don't remember the procedure...
Hello I see that it's a subcircuit. In this case, if you want to use the symbol for PMOS, then Ctrl-right-click on it, rename MP to X and then rename PMOS to IRLML5103. Of course, having the subcircuit's text as a SPICE directive on the schematic or in a custom library is necessary. Merry Christmas to you, too Vlad |
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Re: Spice model
John Woodgate
In message <l8sctp+q9tj4j@...>, dated Wed, 18 Dec 2013, partho.duet@... writes:
How can I get model of c828 trasistor. Please help.It's probably a 2SC828; Japanese transistors often don't have the '2S' marked. It appears to be the same as a BC547 and Spice models of that and its relatives are widely available. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Nondum ex silvis sumus John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK |
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Re: Odd behaviour when attempting to simulate an LTC3633 switching regulator.
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The LTC3633 isn't really the right part to use, if
you want 98mA output current.
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1uH is not an absurdly low value, in fact it's
probably too high for 4MHz operation. The ripple current should be sized for
~40% of the max output current the chip is designed for, consistent with the
internal current-sense range - notwithstanding the actual load current. Suggest
you?look at the numerous design examples, with correctly-sized component
values.
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Re: How do I correctly install CD4000.lib into LTSpiceIV
John Woodgate
In message <l8s98e+1bt8oqb@...>, dated Wed, 18 Dec 2013, fraser.phillips@... writes:
I have managed to locate a CD4000.lib zip file - I have attempted to download an example which has the 'include CD4000.lib' listed on the schematic, however, I keep getting the following error:You probably put the file in a place where LTspice doesn't look for it or Windows hides it. The best place for it is in the same folder as your schematic. Don't put *anything* in the LTspice files in the Program Files folder. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Nondum ex silvis sumus John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK |
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Re: Membership renewal problem ....
John Woodgate
In message <CALBs-TiyNyiDGCR5spojfv-1bnxAjbrU3Wv1CkREMu81ne9=HQ@...>, dated Wed, 18 Dec 2013, Andy <Andrew.Ingraham@...> writes:
I thought a Yahoo ID *was* a Yahoo account.Not exactly. You get a Yahoo email address when you set up a Yahoo identity, and you can associate other email addresses with it. But Yahoo could cancel your Yahoo email address if you don't use it, without cancelling your Yahoo identity. Indeed, there seems to be no reason to cancel an identity if it's not used, because if it's not used, it's as if it didn't exist. -- OOO - Own Opinions Only. With best wishes. See www.jmwa.demon.co.uk Nondum ex silvis sumus John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK |
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Odd behaviour when attempting to simulate an LTC3633 switching regulator.
I am using the ltspice simulator to simulate a design based on the LTC3633.? I have little confidence in the efficiency calculation.
If i design the regulator to run at 4MHz with an output of 1.1V@98mA according to the formula defined in the LTC3633 datasheet the regulator needs a 6.4uH inductor and an output capacitor of 1.4uF.? When I simulate this in ltspice using the LTC3633 I get an efficiency of around 59% If I then change the inductor to a rather small value of 1u for example the efficiency rises to around 70%.? I do not understand why this happens.? Why would using an adsurdly low inductor value increase the efficiency percentage of the model? What is the best way to determine the efficiency of a switching regulator using the ltspice software? I have included the spice netlist of the model below. * U:\jobs\13_12_M154 regulator simulations\simulated\LTC3633_12_to_1V1_experiment.asc V1 IN 0 12 Rser=1 XU1 NC_01 N001 IN N001 N008 IN 0 NC_02 N007 NC_03 N001 OUT1 N005 MP_01 IN MP_02 N003 IN N001 N002 IN MP_03 N004 MP_04 OUT2 N001 NC_04 N006 0 LTC3633 C1 0 N001 2.2? L1 N004 OUT2 1? Rser=14m C2 N002 N004 .1? R1 OUT2 N006 8.2k R2 N006 0 10K R3 N008 0 80.2K C4 OUT2 0 47? Irms=0 Rser=0.002 Lser=0 L2 N005 OUT1 1? Rser=14m C5 N003 N005 .1? R4 OUT1 N007 8.2K R5 N007 0 10K C6 OUT1 0 1.4? V=6.3 Irms=0 Rser=0.0008 Lser=0 C7 IN 0 47? V=6.3 Irms=0 Rser=0.002 Lser=0 mfg="TDK" pn="C4532X5ROJ47@M" type="X5R" x2 I1 OUT1 0 0.098 I2 OUT2 0 0 .tran 0 2ms 1ms steady startup nodiscard uic * Note:\n? If the simulation model is not found please update with the "Sync Release" command from the "Tools" menu.\n? It remains the customer's responsibility to verify proper and reliable operation in the actual application.\n? Component substitution and printed circuit board layout may significantly affect circuit performance or reliability\n? Contact your local sales representative for assistance. This circuit is distributed to customers only for use with LTC parts\n? Copyright ? 2011 Linear Technology Inc. All rights reserved. * LTC3633? - Dual Channel 3A, 15V Monolithic Synchronous Step-Down Regulator\n1.1V/0.9V Buck Regulator with 2.5V LDO Output\nInput: 12V?????? Output1:1V1 @ 0.5A?????? Output2: 2.5V @ 2A * 3x3mm * 4x4mm .lib LTC3633.sub .backanno .end |
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