Re: Sub circuit heat dissipation not showing

Hello Brad,

> What I am missing something?

Ctrl left mouse click on the power formula in the waveform window. Then you will get a single number which is the average power.

Best regards,

Helmut

Re: Sub circuit heat dissipation not showing

John Woodgate

#90101

Not an answer to your question, but there is **no such thing** as 'RMS power'. The product of RMS voltage and RMS current with zero phase difference is 'average power'.

For pedants, one can calculate a quantity by applying the calculus for RMS to instantaneous power, but it has no physical significance.

With best wishes DESIGN IT IN! OOO – Own Opinions Only
 <> www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England

Sylvae in aeternum manent.

From: LTspice@... [mailto:LTspice@...]
Sent: Thursday, August 4, 2016 3:47 AM
To: LTspice@...
Subject: [LTspice] Re: Sub circuit heat dissipation not showing

Helmut,

I know you said "All the Darlington transistors in my examples correctly plot power" But that's not my issue.

I can see the plot/s but I was thinking I would see "dissipation" in watts as with BJT transistors or other non-sub circuits.

I did download and run the TIP142 sub circuit files. I get the same thing. "Left click to plot Q10 dissipation. V(c10)*Ix(Q10:C)+V(b10)*Ix(Q10:B)". But as I think I said earlier I was expecting "dissipation = XXXX" at the end of the formula.

Interestingly, I noticed that R2 said "dissipation = 0" but when I plot it I see about 850 mW for about 50 us at 50% duty cycle. So wouldn't there be some power dissipation here??

Although the plot (for dissipation) is very useful I guess I was thinking I would see a single value for power dissipation (probably RMS power) for that darlington or even R2.

What I am missing something??

Remember I am a beginner and Thanks,
Brad

---In LTspice@... <mailto:LTspice@...> , <helmutsennewald@... <mailto:helmutsennewald@...> > wrote :
Hello,

The power dissipation of the TIP142 from our Files section will be correctly displayed.
TIP_142_test.zip
 ahoo.com/neo/groups/LTspice/files/%20Lib/ <>

Here are a few more examples. Their power will be displayed too.

All the Darlington transistors in my examples correctly plot power.

In therory there are subcircuits possible where LTspice doesn't plot the power due to special combinations of sources internally connected to the pins of a subcircuit.

You should upload your files for a test.

Best regards,
Helmut

I download and ran the TIP142 sub circuit files. I get the same thing. "Left click to plot Q10 dissipation. V(c10)*Ix(Q10:C)+V(b10)*Ix(Q10:B)" I can see the plot but I was thinking I would see "dissipation" in watts as with BJT transistors.

Interestingly, I noticed that R2 said "dissipation = 0" but when I plot it I see about 850 mW for about 50 us at 50% duty cycle. So wouldn't there be some power dissipation here??

Although the plot (for dissipation) is very useful I guess I was thinking I would see a single value for power dissipation (probably RMS power) for that darlington or even R2.

What I am missing something??

Thanks,
Brad

---In LTspice@... <mailto:LTspice@...> , <helmutsennewald@... <mailto:helmutsennewald@...> > wrote :
Hello,

The power dissipation of the TIP142 from our Files section will be correctly displayed.
TIP_142_test.zip

Here are a few more examples. Their power will be displayed too.

All the Darlington transistors in my examples correctly plot power.

In therory there are subcircuits possible where LTspice doesn't plot the power due to special combinations of sources internally connected to the pins of a subcircuit.

You should upload your files for a test.

Best regards,
Helmut

Re: "4 GROUP.zip" upload

#90236

Thanks Andy, I'm still working on fully understanding your post.

Thanks?Bordodynov, I added your 2 model.s ?The BS250P returned and error. "Error on line 602 : .model bs250p vdmos pchan rg=160 vto=-3.193 rs=2.041 rd=0.697 is=2e-13 kp=0.277 cjo=105p pb=1 lambda=1.2e-2 rb=0.309 rds=1.2e8 cgdmax=57p cgdmin=5p cgs=47p tt=86.56n bv=45 ibv=10u

* Unrecognized parameter "pb" -- ignored" so I deleted the PB component.?

Andy, I understand the possibility of sharing a file that has my custom components with others, as is the case where I used the 2n7000 instead of the 2n7002, they both have the same parameters in my CMP file, so I thinking that all my custom component should start with the letter K or J just to remind me to include the model or sub file. Is there a "place" that has the definition of all the parameters of components, vto=-3, lambda=1.2e and such?

Thanks for the help,

Jeff

Re: Need help to design a transimpedance amplifier

#90099

开云体育

Hi there,

Please, Please see an Idea I have posted in the Temp Folders of this group. (Photo Amplifier15.asc)

Best regards,

Michael P Kiwanuka

To: LTspice@...
From: LTspice@...
Date: Fri, 5 Aug 2016 09:10:31 +0200
Subject: Re: [LTspice] Re: Need help to design a transimpedance amplifier

I tried to answer a couple of days ago, but it didn't come through, so I'll write it again:
The noise you observe compes from the fact that you have these big 100k resistors in the non-inverting inputs. The OPA2846 has a very high NOISE CURRENT; it is designed for low-impedance sources. There should be no resistor in the non-inverting inputs, or very low (similar to the APD's equivalent resistance); if used, this resistor should be bypassed by a capacitor, for near-zero impedance within the circuit's BW. That's VLN 101.

Le 04/08/2016 à 09:31, t.obulesu@... [LTspice] a écrit?:

?
Let me say why am looking for new design..
We are currently using the receiver module which has three stages:
1. Trans Impedance stage
2. High Pass filter (HPF) stage
3. Unity gain amplifier (just for inverting the output of the HPF)

Well...we used LM2662 as a -5V supply..
Here on we could see the hell noise below 100kHz..
I couldn't get rid of this noise by using bypass caps..but I could just reduced it..
Yet there is a lot of noise all across the circuit ranging from few kHz to hundreds of MHz...

are the links where I have uploaded couple of documents..

I really don't know what sort of noise it is and from where it is coming...

L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast.

Re: Henry's current transformer problem

#90108

From the available data we have not seen Br depending temperature change from 25° C to 100° C.

Bordodynov.

05.08.2016, 15:56, "hkafeman@... [LTspice]" <ltspice@...>:

Show quoted text

Borodoynov

Thank you that looks like a good typical material to use.

My understanding is then that given that I am operating at only 50Hz with just some high frequency transients, that any core losses will be insignificant.

Then I can model in LTSpice the effects of ambient temperature using e.g.:

Hc = 22 at 25C decreasing by 0.12 % per C
Bs = 490m at 25C decreasing by 0.27 % per C
Br = 100m at 25C - Does this have a temperature coefficient?

Thanks and Regards
Henry Kafeman

Re: Henry's current transformer problem

[email protected]

#90097

Borodoynov

Thank you that looks like a good typical material to use.

My understanding is then that given that I am operating at only 50Hz with just some high frequency transients, that any core losses will be insignificant.

Then I can model in LTSpice the effects of ambient temperature using e.g.:

Hc = 22 at 25C decreasing by 0.12 % per C
Bs = 490m at 25C decreasing by 0.27 % per C
Br = 100m at 25C - Does this have a temperature coefficient?

Thanks and Regards
Henry Kafeman

Re: Henry's current transformer problem

#90096

Hello Henry Kafeman.
See material N41
BS (25 °C)=490mT
BS (100 °C)=390mT
Hc (25 °C)=22A/m
Hc (100 °C)=20A/m
Br=0.1T

Power
Transformer (low loss)

f<100 kHz

N27 (?i = 2000 ) low cost, hi-power
N41 (?i = 2800 ) current transformer
N51 (?i = 3000 ) loss min. @ 40°C

Bordodynov.

05.08.2016, 14:27, "HKafeman hkafeman@... [LTspice]" <ltspice@...>:

Show quoted text

analogspiceman and Andy

Thank you for your replies.

I appreciate that there are many different Ferrite materials. I do not know which specific material my CT is made of, so am looking to model a typical material.

The typical Hc value for Ferrites I found was 0.2 Oersteds.

I now realise that LTSpice uses Hc in A/m and "0.2 Oersteds = 15.9 A/m". So I need to use Hc in LTSpice of 15.9.

Sorry for the confusion about the path length (for some strange reason I was getting confused with area!) - of course it is Pi * d for the CT (with outer and inner diameters of 28.5 and 17.0mm). So in my case is 71.47mm using the average diameter, so Lm is 71.47m.

Similarly the Area for my CT (width 18mm), A is 103.5u.

Can you help me out with one other aspect of my CT please?

The manufacturer states it is rated at 0.01VA. Now I think this is the maximum Voltage * Current through the Burden Resistor.

But how does this relate to the Secondary Coil power dissipation and also dissipation in the Core?

What happens if this value is exceeded? Does it just mean that the Secondary Coil and Core are heated up significantly which affects the linearity, etc.?

Can this affect be modelled?

Thanks and Regards

Henry Kafeman

Re: Henry's current transformer problem

HKafeman

#90095

analogspiceman and Andy

Thank you for your replies.

I appreciate that there are many different Ferrite materials. I do not know which specific material my CT is made of, so am looking to model a typical material.

The typical Hc value for Ferrites I found was 0.2 Oersteds.

I now realise that LTSpice uses Hc in A/m and "0.2 Oersteds = 15.9 A/m". So I need to use Hc in LTSpice of 15.9.

Sorry for the confusion about the path length (for some strange reason I was getting confused with area!) - of course it is Pi * d for the CT (with outer and inner diameters of 28.5 and 17.0mm). So in my case is 71.47mm using the average diameter, so Lm is 71.47m.

Similarly the Area for my CT (width 18mm), A is 103.5u.

?

Can you help me out with one other aspect of my CT please?

The manufacturer states it is rated at 0.01VA. Now I think this is the maximum Voltage * Current through the Burden Resistor.

But how does this relate to the Secondary Coil power dissipation and also dissipation in the Core?

What happens if this value is exceeded? Does it just mean that the Secondary Coil and Core are heated up significantly which affects the linearity, etc.?

Can this affect be modelled?

Thanks and Regards

Henry Kafeman

Re: Need help to design a transimpedance amplifier

[email protected]

#90093

Thanks for your response Jerry Lee Marcel..
But...I could see this noise everywhere in the circuit..
I mean power supply as well...

Re: Need help to design a transimpedance amplifier

#90110

I design a lot of TIA type of amp. I don't know what kind of speed you are looking for. But your requirement is very easy, the lowest is 200nA. Any opamp with bias current of less than 10nA will work good enough.

I use LTC6268 for my design. It is likely to be way over kill for you. Check out other opamp from LT. A tip for you, I tested out a lot of opamps from Ti and Maxim. Most don't quite meet the spec on the noise even the spec say so. LT6268 really produce the result according to the spec.

Contact Glen Brisebois in LT linear opamp application group. He is very knowledgeable and helpful. I visited him in the head quarters once and he showed me a lot of tricks.

Re: Need help to design a transimpedance amplifier

#90090

开云体育

I tried to answer a couple of days ago, but it didn't come through, so I'll write it again:

The noise you observe compes from the fact that you have these big 100k resistors in the non-inverting inputs. The OPA2846 has a very high NOISE CURRENT; it is designed for low-impedance sources. There should be no resistor in the non-inverting inputs, or very low (similar to the APD's equivalent resistance); if used, this resistor should be bypassed by a capacitor, for near-zero impedance within the circuit's BW. That's VLN 101.

Le 04/08/2016 à 09:31, t.obulesu@... [LTspice] a écrit?:

?

Let me say why am looking for new design..
We are currently using the receiver module which has three stages:
1. Trans Impedance stage
2. High Pass filter (HPF) stage
3. Unity gain amplifier (just for inverting the output of the HPF)

Well...we used LM2662 as a -5V supply..
Here on we could see the hell noise below 100kHz..
I couldn't get rid of this noise by using bypass caps..but I could just reduced it..
Yet there is a lot of noise all across the circuit ranging from few kHz to hundreds of MHz...

are the links where I have uploaded couple of documents..

I really don't know what sort of noise it is and from where it is coming...

L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast.

Re: "4 GROUP.zip" upload

#90089

I am sorry.
.MODEL BS250P ....

Bordodynov. 

05.08.2016, 09:35, "Александр Бордодынов BordodunovAlex@... [LTspice]" <ltspice@...>:

Show quoted text

Hi.
.model BS170 VDMOS VTO=1.824 RG=270 RS=1.572 RD=1.436 RB=.768 KP=.1233 Cgdmax=20p Cgdmin=3p CGS=28p Cjo=35p Rds=1.2E8 IS=5p Bv=60 Ibv=10u Tt=161.6n
.MODEL BS250 VDMOS pchan Rg=160 VTO=-3.193 RS=2.041 RD=0.697 IS=2E-13 KP=0.277 Cjo=105p PB=1 LAMBDA=1.2E-2 RB=0.309 Rds=1.2E8 Cgdmax=57p Cgdmin=5p CGS=47p TT=86.56n BV=45 IBV=10u

Bordodynov.

05.08.2016, 08:56, "Andy ai.egrps@... [LTspice]" <ltspice@...>:
Jeff asked:

? ?"Is there an easy or a standard way to make a model for these transistors that can be included in LIB/cmp/standard.mos?"

For the?BS250P and BS170?transistor models you used, no, there isn't.? Those particular models are .SUBCKTs.? You can't have a subcircuit model in the "standard.mos" file.? That file is only for transistor models that use just the .MODEL syntax; it's not for subcircuits.

But aside from that .. this is a touchy question.

Aside from MS-Windows, there is nothing stopping you from editing your lib&#92;cmp&#92;standard.mos file, and adding your own MOSFET models to it if they are .MODEL models.? In fact, the LTspice Help pages even recommend it (Help: F.A.Q. -> MOSFET Models), so Mike Engelhardt thought it was OK.? Many people here in this group recommend against editing that file, but you can.

Windows might require you to be the Administrator, when you edit the file.

Of the lib&#92;cmp&#92;standard.* files, these ones are text files and could be edited directly:

standard.bjt
standard.dio
standard.jft
standard.mos

(The others are binary.)

The format is ordinary SPICE Netlist format, and should be just a .MODEL statement for each diode or transistor.? Obviously, device names must not clash, and standard SPICE rules apply about continuation lines.? Also, use only a decent text editor that does not add stray binary bytes here and there.? Notepad is best avoided.

Indeed there are enhanced versions of the standard.* files with many more transistors in them, which people have contributed to the LTspice user community.? They can be found in a few places in this group's Files area, and on the LTwiki website (ltwiki.org).

One of the problems with editing your standard.mos file (rather than pasting .MODEL statements on your schematic or having them in a separate file), is that you may forget that other LTspice users don't have those same transistors in their LTspice installation.? Then when you send them your schematic that uses one of those transistors, the schematic cannot be run.? Having those .MODEL statements separate, makes it more likely for you to send the .MODELs along with your schematic.

Regards,
Andy

Re: "4 GROUP.zip" upload

#90088

Hi.
.model BS170 VDMOS VTO=1.824 RG=270 RS=1.572 RD=1.436 RB=.768 KP=.1233 Cgdmax=20p Cgdmin=3p CGS=28p Cjo=35p Rds=1.2E8 IS=5p Bv=60 Ibv=10u Tt=161.6n
.MODEL BS250 VDMOS pchan Rg=160 VTO=-3.193 RS=2.041 RD=0.697 IS=2E-13 KP=0.277 Cjo=105p PB=1 LAMBDA=1.2E-2 RB=0.309 Rds=1.2E8 Cgdmax=57p Cgdmin=5p CGS=47p TT=86.56n BV=45 IBV=10u

Bordodynov.

05.08.2016, 08:56, "Andy ai.egrps@... [LTspice]" <ltspice@...>:

Show quoted text

Jeff asked:

? ?"Is there an easy or a standard way to make a model for these transistors that can be included in LIB/cmp/standard.mos?"

For the?BS250P and BS170?transistor models you used, no, there isn't.? Those particular models are .SUBCKTs.? You can't have a subcircuit model in the "standard.mos" file.? That file is only for transistor models that use just the .MODEL syntax; it's not for subcircuits.

But aside from that .. this is a touchy question.

Aside from MS-Windows, there is nothing stopping you from editing your lib&#92;cmp&#92;standard.mos file, and adding your own MOSFET models to it if they are .MODEL models.? In fact, the LTspice Help pages even recommend it (Help: F.A.Q. -> MOSFET Models), so Mike Engelhardt thought it was OK.? Many people here in this group recommend against editing that file, but you can.

Windows might require you to be the Administrator, when you edit the file.

Of the lib&#92;cmp&#92;standard.* files, these ones are text files and could be edited directly:

standard.bjt
standard.dio
standard.jft
standard.mos

(The others are binary.)

The format is ordinary SPICE Netlist format, and should be just a .MODEL statement for each diode or transistor.? Obviously, device names must not clash, and standard SPICE rules apply about continuation lines.? Also, use only a decent text editor that does not add stray binary bytes here and there.? Notepad is best avoided.

Indeed there are enhanced versions of the standard.* files with many more transistors in them, which people have contributed to the LTspice user community.? They can be found in a few places in this group's Files area, and on the LTwiki website (ltwiki.org).

One of the problems with editing your standard.mos file (rather than pasting .MODEL statements on your schematic or having them in a separate file), is that you may forget that other LTspice users don't have those same transistors in their LTspice installation.? Then when you send them your schematic that uses one of those transistors, the schematic cannot be run.? Having those .MODEL statements separate, makes it more likely for you to send the .MODELs along with your schematic.

Regards,
Andy

Re: PWL TRIGGER syntax

#90087

> does somebody have problem with this syntax? PWL (0 0 1m 1 2m 1 3m 0) TRIGGER V(n003)>1
> the error msg I receieve is Unknown parameter "trigger"

Without knowing what you have, if you're using the "trigger" keyword with current sources, it doesn't work, only for voltage sources.

Vlad
______________________
-- holding, among others:
a universal analog/digital filter, block-level models
for power electronics (and not only), math blocks
with a more stream-lined approach, some digital
ADC, DAC, (synchronous-)counter, JKflop, etc.

Re: BS250 & BS170 SIM

#90084

Jeff wrote:

? ?"they look like they should work, but the don't, how can I add them to my CMP folder, that is what is the correct model layout."

I just noticed you sent this question two days ago.? It finally went through Yahoo's servers!? It got held up that long.

I think you already have the answer to this question.

Andy

Re: Sub circuit heat dissipation not showing

#90080

Brad wrote:

? ?"I hit SEND but it isn't here ?? I don't understand. Humm.."

Yup.? Yahoo was having major problems yesterday.? Hopefully that is over.? File uploads/downloads seemed to be unaffected, but messages were not.? I got a tip from elsewhere, that the larger your message, the more likely it was to get stuck, for 24 hours or more.

? ?"Basically I said I uploaded the TIP142 sub circuit?..."

I am not seeing that.? It's not in "Temp", and there is no file upload listed for you from the last two days (or ever).? Are you sure you uploaded it to this group?? File uploads didn't get delayed, so if you uploaded it and did not get an error message right away, it would be here.

It would be good to see the simulation you have that has this problem.

I am a bit confused about your references to the formula versus the value.? Are you looking for a graph of power dissipation versus time?? To graph power, LTspice uses a formula of pin currents and voltages.? You will see that formula at the top of the plot window, but you should also see the plot, from that formula, within the plot window.? There is a separate action to integrate the area under a plot.? Did you do that?

Help page: Waveform Viewer -> Data Trace Selection

... and then look about half-way down that page.

? ?"BTW. What is the Poll button about??"

Yahoo!Groups allow group-wide polls, or votes, where members get to "cast their ballot" by choosing one or more choices.? They are not particularly useful here.? I do not recommend them.? If you have a specific idea in mind, please first send them in an email to the group's Moderators (ltspice-owner @ ).

? ?"Also how do I get emails just on this conversation and not all the others in the LT Spice group."

Sorry, it's all or nothing.? Yahoo doesn't filter what it sends you.

But you have the perfect email service (Gmail) where you can do the filtering on your end.

You can direct all the messages from this group to somewhere other than your Inbox ("Archive" them), and then they won't clutter your Inbox anymore.

The other option you have is to select Daily Digest emails instead of Individual Emails.

Andy

Re: LTspice IV (NOT RESPONDING)

#90117

There is one thing I can do with LTspice on my home computer that causes Windows to think it is not responding.? If I turn on Mark Data Points in the waveform display, and if the density of points is high enough, LTspice takes a VERY long time re-drawing the screen over and over and over again (infinite loop?).? I guess it might be an interaction with the display driver, and maybe LTspice times out and starts over, repeatedly.? When this happens, I can sometimes stop it, but most of the time the only thing I can do is go to the Windows Task Manager and kill LTspice.

So I hesitate to call this just a Windows thing.

Andy

?

Re: PWL TRIGGER syntax

#90079

Hello,

The 32 bit version of LTspiceXVII had a problem with PWL in early versions.

Do you use the 32 bit version LTspiceXVII.exe(x86)??

Please update LTspiceXVII to the latest version.

Tools > Sync release

Best regards,

Helmut

Re: "4 GROUP.zip" upload

#90086

Jeff asked:

? ?"Is there an easy or a standard way to make a model for these transistors that can be included in LIB/cmp/standard.mos?"

For the?BS250P and BS170?transistor models you used, no, there isn't.? Those particular models are .SUBCKTs.? You can't have a subcircuit model in the "standard.mos" file.? That file is only for transistor models that use just the .MODEL syntax; it's not for subcircuits.

But aside from that .. this is a touchy question.

Aside from MS-Windows, there is nothing stopping you from editing your lib\cmp\standard.mos file, and adding your own MOSFET models to it if they are .MODEL models.? In fact, the LTspice Help pages even recommend it (Help: F.A.Q. -> MOSFET Models), so Mike Engelhardt thought it was OK.? Many people here in this group recommend against editing that file, but you can.

Windows might require you to be the Administrator, when you edit the file.

Of the lib\cmp\standard.* files, these ones are text files and could be edited directly:

standard.bjt

standard.dio

standard.jft

standard.mos

(The others are binary.)

The format is ordinary SPICE Netlist format, and should be just a .MODEL statement for each diode or transistor.? Obviously, device names must not clash, and standard SPICE rules apply about continuation lines.? Also, use only a decent text editor that does not add stray binary bytes here and there.? Notepad is best avoided.

Indeed there are enhanced versions of the standard.* files with many more transistors in them, which people have contributed to the LTspice user community.? They can be found in a few places in this group's Files area, and on the LTwiki website ().

One of the problems with editing your standard.mos file (rather than pasting .MODEL statements on your schematic or having them in a separate file), is that you may forget that other LTspice users don't have those same transistors in their LTspice installation.? Then when you send them your schematic that uses one of those transistors, the schematic cannot be run.? Having those .MODEL statements separate, makes it more likely for you to send the .MODELs along with your schematic.

Regards,

Andy

Re: high frequency MHz and GHz range BJTtransistor or Mosfet

#90076

The major problem with tuned RF design is you don't know where the optimize point is for minimum reflection and maximum power transfer. You have 3 variables, L, R and C and you have more than one optimized point depends on what is the other requirements. Smith Chart show you in graph every single point so you can choose the RLC values at the same time. It can get very complicated to vary 3 values in LTSpice.

In another words, LTSpice is good if you know the values and see what is the outcome. But it is not good if you are searching for the optimize values of 3 components or more.

Now, for wide band circuits, Smith Chart is useless. I think that's where LTSpice shines.

Bottom line, I think it's the "iteration" thing that's where Smith Chart simulation is strong.