L6565

jgalea · ‎2009-09-18

Posted on September 18, 2009 at 12:37

L6565

jgalea · ‎2011-05-17

Posted on May 17, 2011 at 13:24

Hi All. Please does any one have a circuit to use the L656x in non-isolated buck controller. The application notes, are all on the isolated power supply. I need it to provide power for the STM32 micro from AC source. I used the circuit that is attached but unluckily it did not work. Im trying my best and now referred to the forums. Thanks Johann

danish · ‎2011-05-17

Posted on May 17, 2011 at 13:24

Your attachment looked to me like a marketing-flyer rather without all the vital information needed to select appropriate component values etc.

Have you studied the appropriate datasheet at (for example)

http://www.st.com/stonline/products/literature/ds/7587/l6565.pdf

?

Hope this helps,

Danish

benedwards19 · ‎2011-05-17

Posted on May 17, 2011 at 13:24

The circuit you attached is designed specifically for LED drive. It doesn't regulate output voltage, instead it regulates output current. The ''output'' is across the LED and is not referenced to the circuit ground. Also, this circuit is optimized for ~20-30 watts, not the 0.25 watt used by the STM32.

I would suggest looking at the ST VIPER or Power Integrations (www.powerint.com) line of parts to use to make an offline supply. If you are not a power supply expert, these parts have design software that will help you design your supply.

I would also not recommend using a non-isolated buck design unless cost is your primary concern. Isolation allows you to safely debug your code without special hardware.

If you must use the L6565, I can help you make it work, but I think you would be much better off using the VIPER or Power Integrations chips.

Good luck,

Ben

jgalea · ‎2011-05-17

Posted on May 17, 2011 at 13:24

Thanks for your suggestions. Will keep them in mind.

Johann