LTspice tutorial - FREQ function

[@WolfgangViehmann-t2m]

These are the BEST LTspice tutorials I found so far. Thank you very much

[@paps.bricole]

Awesome ! Thanks. Is the STL file for the VNA support somewhere plz ?

[@dominikgs]

Very nice video!!! Thank you for sharing your knowledge. If I had one wish free I would love to see an in detail explanation how the model at 10:46 works and if there are other modeling possibilities. Nevertheless very nice so thank you!

[@FesZElectronics]

I'll have to study that part in a bit more detail before I can do a proper explanation :D anyway, in case you need it, I left a document in the video description that highlights the circuit for the 2 port Sparameter models as well.

[@ghlscitel6714]

Good presentation! Congrats!

[@olivierconet7995]

Very nice tutorial. I really learned something useful, thanks. To convert S11 file to simulation model, a python script, may be ?

[@FesZElectronics]

That certainly is a possibility, although its not something I personally know how to do :D

[@Kashif_Javaid]

Great job, you should help write the LTspice manual, 😅

[@MarceloMoraes]

What a Great Tutorial! Could you give us the VNA lib? in order we can also simulate the component you measured, please. Cheers from Brazil

[@FesZElectronics]

I added it into the description.

[@vipinpnair]

Thanks for this information. I noticed a flow in this. When i model frequency dependent resistor in ltspice, it works well in AC analysis. But its not working in time domain. E.g performance on a square wave. Am I missing something?

[@FesZElectronics]

No, you did not miss anything... but I think I mentioned this - the Freq function will only work for AC simulations..

[@copernicofelinis]

So, it's like PWL but in the frequency domain...

[@turkialshehri9762]

My brother , I need your help. I am currently working on a graduate project to operate a water pump through direct solar panels, and you know that the voltage will change a lot. My design is to build a DC to DC converter. The voltage range between 100 volts in the morning and evening to 350 volts at noon. can it works in this large range of wide range of voltage without getting core saturated or losing his job ,Do u think by changing switching freq and duty cycle can it work fine?.Arduino nano as switching frequency will be

[@janpetrik2566]

Hello, @FesZElectronics would you know how to define behavior FREQ at DC ?

[@FesZElectronics]

I guess you are asking for the case where you are using FREQ to define a resistor - to help with establishing the DC operating point. For this use case, the DC value of the resistor will be the x in R=x FREQ (...) ; I used 1 but you can use any other value there, its just that the FREQ table admittances need to be re-scaled to take into account the initial DC "x" value. If you need an infinite DC value, you can put the resistor in series with a capacitor that has a capacitance of 1 (1farad) - this way its an open circuit under DC conditions and more or less 0 ohm under your use case frequency.

[@janpetrik2566]

@@FesZElectronics Thanks, I'll try.

[@Mewanrahnam575]

A real signal such as a sound wave is AC in nature and its mathematical signal representation is expressed as a a sinusoid.My question is how a varyring DC signal from DC temperature sensor signal and its mathematical signal representation is expressed?How does its waveform differ from AC signal sunusoid and do we analyse DC varying signal?

[@FesZElectronics]

DC by definition is constant; if there is any variation, however slow (like the temperature signal) it becomes AC; now in real life, every signal could be considered AC, but at some point you make the assumption that it isn't just to make the analysis easy. You can also perform an analysis over a short period of time over which the signal is actually constant, and thus perform multiple analysis of "DC signals" to observe the long term AC behaviour. For the purpose of mathematical analysis, you can decompose a signal into an AC and DC component - for ex the 5V of a switching converter has a DC of 5V and an AC ripple of 100mV (as example).

[@catalinm756]

Hello. Do you have any experience with ngspice/ Berkeley spice?

[@PainterVierax]

As it goes with FOSS, ngspice is certainly most advanced and permissive but less intuitive and easy to use than the LTspice freeware. Though ngspice has a complete documentation and Qucs-S and Kicad provide nice alternative GUI.

[@jimhutton4183]

Promo SM 💐