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Design >> High-Power Design >> looking for ccm/dcm (combined) model
https://designers-guide.org/forum/YaBB.pl?num=1167832862

Message started by tg on Jan 3^rd, 2007, 6:01am

Title: looking for ccm/dcm (combined) model
Post by tg on Jan 3^rd, 2007, 6:01am

Hi, Im in the buck business...
I would like to simulate (spectre + veriloga) a buck converter (ac + tran)
with a switch veriloga model (ccm and dcm combined model).
I couldnt find any but Im sure there is such model somewhere
Could you please help me in finding it
Tx

Title: Re: looking for ccm/dcm (combined) model
Post by Jess Chen on Jan 3^rd, 2007, 11:30am

I assume you want a state space averaged model. I do not have any VerilogA implementations of a dual-mode converter but I have attached an old paper describing how to do it with macro models. Perhaps it will give you some ideas for a VerilogA implementation. I will follow up with one of the papers referenced by the paper attached to this post.

We waded through some horrendous convergence problems with the macro models. Hopefully VerilogA circumvents those problems.

-Jess

Title: Re: looking for ccm/dcm (combined) model
Post by Jess Chen on Jan 3^rd, 2007, 11:35am

Here's the other paper.

Somewhere under this subject I list a book by Bennet which also discusses dual-mode SPICE models. When I get home tonight, I can post that reference to this thread too. Bennet also describes macro models. By "macro model", I mean behavioral models composed of SPICE or Spectre primitives, not VerilogA. Before VerilogA existed, that is how we did behavioral modeling.

-Jess

Title: Re: looking for ccm/dcm (combined) model
Post by tg on Jan 4^th, 2007, 3:25am

Thanx for the information and fast respond
Do you have a solution for the convergence problems with the macro models?

Title: Re: looking for ccm/dcm (combined) model
Post by Jess Chen on Jan 4^th, 2007, 9:19am

Try the model in the '91 paper. That model worked with default tolerances but I don't remember if it was ever applied to a multiple output converter with post regulated outputs.

-Jess

Title: Re: looking for ccm/dcm (combined) model
Post by Jess Chen on Jan 4^th, 2007, 9:33am

There is a book on macro models of switch mode power supplies that includes dual-mode models. The model looks promising but I've never tried it. The book came out after I moved over to RF. I have yet to see a book on VerilogA models of switch mode power supplies but I think the market may be ripe for one.

Johnny Bennett, "Practical Computer Analysis of Switch Mode Power Supplies". CRC Press. Taylor and Francis group. 2006. ISBN 0-8247-5387-9

-Jess

Title: Re: looking for ccm/dcm (combined) model
Post by tg on Jan 5^th, 2007, 4:32am

many thanks, youv`e been very helpful
tg