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Re: using LTSPICE symbols for representation of spice netlist of OPAMP
Hello Andy , I am trying to implement the method you reccomended. I have added the OPAMP2 symbol and made the include command for the ad797.cir file. then I tried to added the spice directive script?
By john23 · #158636 ·
Re: Looking for advice on TRAN timing #FFT
@Tony Thank you for your answer, Tony. Is the new version available in the Files section? I also had a look at the PDF file you mentioned. I presume Tswp stands for sweep time, Tdel for the time you
By Ryu · #158635 ·
Re: Looking for advice on TRAN timing #FFT
I am a little confused whether it works as you expected, or not as you thought and this troubles you. I suspect there could be a problem doing an FFT when .STEPping Tstop, if the requested time
By Andy I · #158634 ·
Re: Looking for advice on TRAN timing #FFT
Maybe I should have mentioned that the D.U.T is nothing extraordinary, it is a Bryston DOA33 replacement (discrete opamp) and? a mere 10dB amplification. -- Ryu
By Ryu · #158633 ·
Re: Looking for advice on TRAN timing #FFT
To all who replied so far a hearty thanks! I will do some more experimenting as supposed by Andy. One more thing that troubles me is: when I step Tstop from let's say 12m to 18m in (1m or whatever)
By Ryu · #158632 ·
Re: Build spice model of transimpedance amplifier
You are not wrong. -- Michael Stokowski LTspice Team Analog Devices Inc.
By mstokowski · #158631 ·
Re: Noise modelling
Thanks, Andy, this helps. The noise (I recently got some scope traces) appears to be uncorrelated to anything like the SMPS, but more likely environmental, within the equipment. Without a spectrum
By Bell, Dave · #158630 ·
Re: Noise modelling
Dave, If you want to study the effectiveness of adding filters to reduce SMPS noise, you could use a B-source with rand(x), random(x), or white(x) to mimic a "typical" SMPS.? When simulated
By Andy I · #158629 ·
Re: Noise modelling
If what you want to do is make a substitute model that also generates semi-random noise, and if you want to do that in the time domain, then I refer you to LTspice's rand(x), random(x), and white(x)
By Andy I · #158628 ·
Re: Noise modelling
I node there was something wrong. More data, please. Is this a physical SMPS, or a design, or a simulation? I guess it might be physical, in which case SPICE simulation may not be of much help. An
By John Woodgate · #158627 ·
Re: Noise modelling
I recommend examining the subcircuit models for LTspice's built-in UniversalOpamps, found in UniversalOpamp.lib.? Pair that with the symbols for each UniversalOpamp to see the typical parameter
By Andy I · #158626 ·
Re: Noise modelling
The OTA is not a simulation mode.? It is a device. Think op-amp, but with a current output instead of voltage.? That's an Operational Transconductance Amplifier. It happens that many OTAs in real
By Andy I · #158625 ·
Noise modelling
Reposting with the right Subject spelling! Sent: Friday, February 21, 2025 11:54 AM To: [email protected] Subject: EXTERNAL: [LTspice] Node modelling I just got tasked with trying to characterize (and
By Bell, Dave · #158624 ·
Noise modelling
I just got tasked with trying to characterize (and filter) a noisy switch-mode power supply, There has been some chatter here about noise generation over the years, but one simulation mode I don't
By Bell, Dave · #158623 ·
Re: 12AU7 tube heater model
Yes. SPICE (and by extension LTspice) adds GMIN and others such as GSHUNT, GFARAD, and GFLOAT wherever they are needed, and that is done internally and they do not appear in the netlist.? That's just
By Andy I · #158622 ·
Re: using LTSPICE symbols for representation of spice netlist of OPAMP
I'm sorry, but that question does not make sense. The photo does not show a symbol menu.? It is a photo of your auto-generated symbol.? If you want to not use the auto-generated symbol, then do not
By Andy I · #158621 ·
Re: 12AU7 tube heater model
BTW, I checked the "Add GMIN across current sources" checkbox in Control Panel. However I can't see anything added or changed in the netlist (SPICE Netlist). Is that a sort of LTspice "internal"
By Carlo · #158620 ·
Re: 3 Phase Voltage Sense model
Andre, Not driving any device, monitoring outputs to determine what the input voltage levels are. Larry
By larryg · #158619 ·
Re: 3 Phase Voltage Sense model
Andy, straightened out the pin order on the schematic symbol to match the .sub file, really thought I had it straight but they were off.? Guess that's what happens when you're doing several things at
By larryg · #158618 ·
Re: using LTSPICE symbols for representation of spice netlist of OPAMP
Hello Andy , very intresting Idea .Indeed I will keep the decomp pin open. I am used to start with the netlist and generating a symbol automatickly. How do I involve the opamp2 symbol into the symbol
By john23 · #158617 ·