Hey guys i need to simulate the LM2596 on pspice or any simulation program. I have downloaded the models on TI (they doesnt work to me, i dont know why) but they are model for 3V, 5V and 12 V output and i dont need them, I need a 24 V output so that's the reason i need the kind -adj.
I saw in this forum a zip for the adj kind but i dont know how to insert it in my circuit becouse in that zip i found files .asc, .plt or .txt and dont know what to do with them. I attach that zip
Well, anyone could explain me how to import that zip models into pspice or supply me another file with a LM2596-adj??
Thanks in advance and karma!!

 

hi Fervi,
Welcome to AAC.
One of our members created a LM2596-Adj LTSpice model.
I will tag him , see if he responds @eetech00
E

 

hi Fervi,
Welcome to AAC.
One of our members created a LM2596-Adj LTSpice model.
I will tag him , see if he responds @eetech00
E

I know but, like i said, i dont know how to import the files in that zip to pspice
I'll talk with @eetech00.
Thank u so much for ur help.

 

hi,
I have tried to those asc files, but I get an error message 'the LM2596 requires 5 parameters, only 4 are specified ' I have tried to debug without success.
E

 

I think i have a hard problem here, i have been for a week trying to simulate it and i couldnt yet.
Btw what did u exactly tried when the program gave u that error??
Fervi

 

hi,
Just tried to run the asc file in LTSpice, it will not run, but puts out that error msg.
Looked thru the txt files to try to identify the missing parameter, no luck.
E

 

Okay thanks E, i'll just wait for any help on this thread.

 

hi,
I have tried to those asc files, but I get an error message 'the LM2596 requires 5 parameters, only 4 are specified ' I have tried to debug without success.
E

Hello,

The LTspice developer (Mike E.) recently made a change to the required parameters for a voltage source. It has caused many complaints from various LTspice users. I'll have to take a look at the LM2596 spice code and fix the errors. Check back here in a day or two.

eT

 

I know but, like i said, i dont know how to import the files in that zip to pspice
I'll talk with @eetech00.
Thank u so much for ur help.

Hi

I'll have to take a look and see if changes are needed to port to pspice.
Check back in a couple days.

eT

 

Hello,

The LTspice developer (Mike E.) recently made a change to the required parameters for a voltage source. It has caused many complaints from various LTspice users. I'll have to take a look at the LM2596 spice code and fix the errors. Check back here in a day or two.

eT

Here is the corrected LM2596 model file.

eT

.

 

Here is the corrected LM2596 model file.

eT

.

Hi eT, i downloaded and unzip that, what do i have to do now? They are files .asc and i dont know what to do with them.
I opened the adj version (the one i need) and i attach what happens to my program.

Fervi

 

Hi eT, i downloaded and unzip that, what do i have to do now? They are files .asc and i dont know what to do with them.
I opened the adj version (the one i need) and i attach what happens to my program.

Fervi

 

Hi eT, i downloaded and unzip that, what do i have to do now? They are files .asc and i dont know what to do with them.
I opened the adj version (the one i need) and i attach what happens to my program.

Fervi

The schematic and model is designed for LTspice. You have to use LTspice.

 

The schematic and model is designed for LTspice. You have to use LTspice.

Okay i downloaded and simulated and it works with 5V output
It just doesnt to a 24V output.
I am using the expression given in some datasheets to calculate the resistors:

R2=R1*(Vout/Vref-1)

Does this LM2596 responds to that expression?
I'm using input voltages between 40-60V. Actually, in real, the LM2596 doesnt work to that large input voltages and i use LM2596HV(High Voltage) i assume this is a question that we can skip in simulation or may u put the limit?

Fervi

 

Okay i downloaded and simulated and it works with 5V output
It just doesnt to a 24V output.
I am using the expression given in some datasheets to calculate the resistors:

R2=R1*(Vout/Vref-1)

Does this LM2596 responds to that expression?

Yes.
You can use any recommended expression from the datasheet.
Make sure to use the adjustable model

I'm using input voltages between 40-60V. Actually, in real, the LM2596 doesnt work to that large input voltages and i use LM2596HV(High Voltage) i assume this is a question that we can skip in simulation or may u put the limit?

Fervi

The model doesn't support that. You, the designer, need to honor the max input specifications from the datasheet or the device will burn up.

Here is a quick example below (input=30V Output = 24V):



eT

 

Yes.
You can use any recommended expression from the datasheet.
Make sure to use the adjustable model



The model doesn't support that. You, the designer, need to honor the max input specifications from the datasheet or the device will burn up.

Here is a quick example below (input=30V Output = 24V):

View attachment 182812

eT

Yeah, due to that reason i'll use the HV version in real (that component version let it have a high voltage)
I was just asking if u created the component with the input limit specification.

Ok, but in ur squematic there are some things i couldnt understand.
Why did u only changed the Vin once and u dint on the *.step param section??Same with Iout, why dint u changed it on .step param too?
how did u changed Iout in the no .step param section? which calculation did u?
thank so much for ur help btw.
Greetings, Fervi.

 

Ok, but in ur squematic there are some things i couldnt understand.
Why did u only changed the Vin once and u dint on the *.step param section??Same with Iout, why dint u changed it on .step param too?

Because it wasn’t necessary for the 24 v demo.

how did u changed Iout in the no .step param section? which calculation did u?
thank so much for ur help btw.
Greetings, Fervi.

The params show the calculation.

eT

 

Could change that 45V max input limitation or tell me how i could change it?
Thanks for ur help and karma
Fervi

 

Hi eetech00,
Thanks for your work and the correcction you made to it.
I now have a working model for the LM2596_ADJ to work with in a linear power supply pre-regulator project i'm working on.
But the model you made seems to have a switching frequency far too low: around 14KHz instead of the 150KHz claimed by the datasheet.
Is there any reason for that ?
Regards
Yffig