Use of LinkSwicth PH Buck in PI Xls
Dear Sir/Madam,
I updated the PI Expert Suite to latest release which is 8.0.6.3. And i found that new updated has the provision for Link Swicth PH buck design and Hiper PLC Design. My doubt what is the use of Link Switch PH Buck option in PI Xls. Is it to calculate the resistor values (RV, RV2, R7,R8, R9) and to calculate the inductance value of the Inductor.
And also ,is it not necessary to choose the Dimming and Non-Dimming option while designing buck design, it does not allow us to use Dimming option if i am going to use Universal input design.
And i don't find RDR-254( which is specified in PI Xls spreadsheet while designing Link Switch PH buck) design in Power Integration website.
And Also let me know does we need to worry about the CMA values while designing the circuit using Buck topology because i tried to generate the values of Inductor in the RDR-257 using EE16(since there is no EE13 core in the list), i get warning for CMA value and it tell me choose larger core, but in RDR-257 u have used EE13 core.
Please explain.
Thanks in Advance,
ShamSundar
GreenLight Electronics
Comments
Dear Spock,
i am afraid that your answer does not clarify my doubts, How exactly the application tell me whether my buck topology design will work or not.
Secondly, i am trying to reproduce the design of RDR-257 in PI Xls but it gives me warning for CMA Value for even EE16 Core, it tells me to choose larger core.But in RDR-257 you have used EE13,and the inductance value i get from PI XLS is 860uH, but in RDR-257 it shows the inductance value is 680uH. So it means we need not worry about CMA value warning, then how can i calculate the value of inductance.Please Explain.
And the PI XLS specifies to see the RDR-254, but i dont find RDR-254 in Power Integration website.
ShamSundar.E
Green Light Electronics
Just Adjust the KP value (increase it) to match the inductance.
I am not sure what you mean by "Will my design work" If you do things correctly, follow the spreadsheet instructions, there is no reason it should not work. Maybe you can be more specific in your questions.
About CMA warning - If there is a warning, the one way is to increase wire gauge thickness or just go to the bench and measure the thermal performance (which is what was doe on RDR257) to see if its acceptable.
About RDR254 reference in PIXls spreadsheet - This seems to be a typ. It should be RDR257 instead.
Buck topology can typically be less costly and typically results in higher efficiency than a Flyback topology. The application will dictate whether or not a buck will be acceptable (from safety requirements point of view)
The RDR257 documentation can be found at
http://www.powerint.com/sites/default/files/PDFFiles/rdr257.pdf