Power supply Design
I want to design a SMPS with universal input and output parameters O/P: 7.5V, 0.5A(cv,cc)using fly-back topology. Please suggest me the IC and design I should follow to meet the requirements considering efficiency on priority.
Comments
Hi,
Thanks for your assistance, I am working with the design you mentioned above, I am
also concern about the efficiency of power supply I am designing. I want to achieve
efficiency about 85%, can you please me suggest design according to this?
-Mohit
Mohit -
Reaching that efficiency on a universal input adapter might be difficult, especially if you're trying to optimize your design for minimum cost. You can probably get pretty close to this specification though. Unfortunately, it's difficult to give you design specifics for such a requirement without actually building it and optimizing it on the bench.
However, there are some things you can do to help maximize the efficiency in a LinkSwitch product design:
-Optimize your design for a specific input voltage (115 or 230 Vac)
-Use a more elaborate clamp circuit such as a RCD or RCD+Zener and raise your voltage clamping level to minimize power losses in the clamp circuitry.
-Add a bias winding to your design to be used for powering the IC.
-Use multiple output rectifiers to reduce their power loss.
-Use an output rectifier with as low of a forward voltage drop as possible.
-Experiment with different transformer designs:
--Minimize primary leakage inductance
--Experiment with different winding configurations and test them on an impedance analyzer to optimize your design for the lowest AC impedance near your switching frequency
--Use a larger core to help minimize core losses
--Consider using a secondary foil winding to minimize AC and DC losses.
-The Traveler
Thank you for the interest in our products!
From the requirements you gave, I would recommend a device from our LinkSwitch-II product family. If you look on our Design Support section of our website, there are a number of reference designs that are very close to the specs you gave. You're free to use and/or modify these designs to fit your application.
http://www.powerint.com/sites/default/files/PDFFiles/di119.pdf
http://www.powerint.com/sites/default/files/PDFFiles/der184.pdf
I would recommend downloading our PI Expert design software as it will greatly simplify the power supply design process when using our products. If you need further assistance, please let me know.
-The Traveler