Simplest, low BOM count 0.25W design

Hello voscreature,

Thank you for interested in using Power Integrations products.

If the output is 3.3V and 10mA, Link-TN2 family with Buck topology should be one option for your design.

You can design with the maximum power you need and run it with our PIxls tool, it will tell you the right inductance and FB resistor you need. below is the link for PIxls.
https://piexpertonline.power.com/site/login

Best Regards

Thanks. I checked

https://ac-dc.power.com/sites/default/files/PDFFiles/der507.pdf

If we load say 10mA on the single 5V output, we "only" achieve around 30% efficiency. Is this what one can expect, even with more tuning efforts? Is it impossible to get somewhere in the 80% region?

Thanks,

Martin

Hello voscreature,

80% for the 5V and 10mA is very hard to achieve. The no load input power itself is more than this. As your output power is so low, all the componet loss will be "significant" compared to the output power, like the feedback resistor, the loss in the MOSFET and diode. 

Best Regards