SMPS using TOPSwitch-GX
Posted by: raghu_patkar
on
Sir,
I am a beginner in SMPS design. I went through the data sheet available in the web,there it is mentioned that the preset ratio of OV to UV is 4.5. I have a doubt,is it possible to change this ratio?
Comments
Thank u very much.
Also, can I get the derivations of the equations used in deign (AN-32).,because I am finding difficult how you assume tc as 3ms,Vro and the equations of Vmin etc?
The UV/OV ratio is fixed (its a function of how much current flows into the L pin. While you cannot change the ratio you can enable only 1 of the 2 functions (ie OV only and UV only functionality is possible)
See the TopSwitch-GX datasheet figures 18 and 19 for this implementation.