20to240VAC/DC input, 10V, 250ma tiny design

Hello pecon,

Go to: http://www.powerint.com/node/4806
See: http://www.powerint.com/sites/default/files/PDFFiles/seminars/2007Seminars_Pt3_TOPSwitch-HXDesignUsingPIExpert.pdf
Also of interest for you: http://www.powerint.com/en/pi-university/courses and: http://www.powerint.com/en/design-support/appstv

Cheers,
PI_Crusher

thanks for a reply but its too wide. We are using your components for many years. I am specifically interested in 20-240VAC/DC SMPS. Hope your response can be more narrow to really help me out in the right direction

Hello pecon,

There are examples for extended input voltage range:
http://www.powerint.com/sites/default/files/PDFFiles/di152.pdf
http://www.powerint.com/sites/default/files/PDFFiles/di153.pdf
See in DI-152 how the floating current source is used to extend the input voltage range. Use a similar technique for your design. Start PI Expert with a standard design, say 85Vac to 265Vac input. Decrease the lower limit as much as possible without getting errors. This will be your starting point. Add the floating current source to supplement the current required by the BP pin, build a prototype and see how low the AC input can go. I assume you will have to go trough a few iterations, maybe you need to declare the output power higher in order to get the desired output power for lower AC input voltage.

Cheers,
PI_ Crusher