UCC28780: UCC28780

robin gangopadhya18

Part Number: UCC28780
Other Parts Discussed in Thread: UCD3138

I have a new application where we need 15V output with max 8.5 amp, say 9 amp.

Input is DC coming out of 3ph PFC with 380V well-regulated voltage. Say, 5% tolerance on it. So input min is 360 V and max is 400V.

We are using the SLUC644 spreadsheet to calculate estimated values of various R, C, L etc in the circuit. We have already run the calculations for a 12V@4 amp, got all values. We are about to go for the fab even. Switches are selected from TIDA01622 design guide in addition to the UCC28780 d/s and our discussions on this forum.

But in 15v case, we get #VALUE in Rcs row.

Cannot determine why is that & which inputs are causing this to happen. They are basically the same as for the 12V case.

I have reported earlier that another value always comes up as -xxx : that is Ropp. Never could determine what causes that.

Any help in fixing Rcs values will be greatly appreciated. So goes for Ropp.

-r

over 6 years ago

0 Mike O' over 6 years ago

TI__Guru* 86286 points

Hello Robin,

Sorry for the issues you are having with the Excel tool.
Could you send the excel tools to us so we can have someone on the applications team evaluate the issues for you?

Regards,

Mike

0 Mike O' over 6 years ago in reply to Mike O'

TI__Guru* 86286 points

Hello Robin,

I discussed this with TI's application team and there is a known issue on the Excel tool which they are working on to resolve. There is a MathCAD design tool available that can be used until the Excel tool is fixed. The applications team mentioned this issue should be resolved soon.

Regards,

Mike

0 robin gangopadhya18 over 6 years ago in reply to Mike O'

Mastermind 6296 points

SLUC664Arg_asars15d_8amp_gap.xlsx SLUC664Arg_asars15v_8amp_gap.xlsxThnx for the prompt reply Mike.

Sure: I am attaching 2 files.

One has "d" in the name- I entered something in the "input" sheet which gave us wrong Rcs. Ropp is always -ve so that has not changed.

However, I made no other changes in the input of the base 12v 48W file excepting output of 15V & power of 125W, & I got Rcs=.139 which makes sense.

BUT the issue is WHAT caused the error in the inputs of the file with "d" in its name?.must be some range values?

This is what I am after....because we have 10 such modules to make for a project!

We need to understand quite a bit more of the design, calculations and power loss so that we keep all modules with max efficiency.

0 robin gangopadhya18 over 6 years ago in reply to Mike O'

Mastermind 6296 points

where can I find the Mathcad file? ...will it run in Matlab?
Very much appreciate discussing this with the app folks.

0 Mike O' over 6 years ago in reply to robin gangopadhya18

TI__Guru* 86286 points

Hello Robin,

MathCAD will not run on Matlab. However you can get a free 30 day trial at the following link.

The applications team should have the Excel design tool fixed within the next 30 days.

Regards,

Mike

0 robin gangopadhya18 over 6 years ago in reply to Mike O'

Mastermind 6296 points

Thnx Mike.

It sounds funny to ask if mathcad file will run in matlab.... I meant a lot more than what I wrote - comical that it is- what I meant was if I rewrite the code in matlab from mathcad after opening it, it should run the "model".

I think all mathcad functions have matlab equivalent.

All I need are the equations. In Excel, these are hidden and cannot be seen, right?

We have matlab full version license because of the control we model in simulink targeted for UCD3138 ( for the PFC module).

I will try to look for the mathcad file in TI site. I hope I find it or else I will request you for it.

-r

0 Mike O' over 6 years ago in reply to robin gangopadhya18

TI__Guru* 86286 points

Hello Robin,

I have attached PDF files of the MathCAD design file if that helps. None of the equations are hidden.

Regards,

Mike

Mathcad - ACF Power Stage Calculations.pdf

4848.Mathcad - UCC28780 ACF Controller Calculations for Gan Power Stage (v6.0 01-18).pdf

0 robin gangopadhya18 over 6 years ago in reply to Mike O'

Mastermind 6296 points

wow: I checked the files...I would do anything possible to get the MathCad trial or buy & run these file to get a deeper understanding of the equations & their impact.

Could you email me the files?

Especially that of Goerke's which is not marked with confidentiality...

I do have the Eval kit & together, we should have no doubts about 1 straight fab without error(hmm)..

thnx Mike

0 Eric Faraci over 6 years ago in reply to robin gangopadhya18

TI__Expert 8210 points

Robin

A direct link to the Mathcad design calculator files for UCC8780 is here http://www.ti.com/lit/zip/sluc644

Best Regards,

Eric

0 Eric Faraci over 6 years ago in reply to Eric Faraci

TI__Expert 8210 points

Robin

The file Mike uploaded incorrectly had a confidentiality marking. We've updated Mike's message to link to documents that have proper markings. Both are public information.

Best Regards,

Eric

0 Eric Faraci over 6 years ago in reply to Eric Faraci

TI__Expert 8210 points

Robin

We have updated the excel calculator for UCC28780 to fix the errors you noticed. You can download the latest corrected version at the link below

http://www.ti.com/lit/zip/sluc664

Best Regards,

Eric

Power management

Power management forum

UCC28780: UCC28780