Help - Overheating causing the controller go into protection temperature

Posted by: egalves on 02/03/2014

Dear,

I performed the installation of a switching power supply using the TNY275 Tinyswitch-III controller with a charge with 5v voltage and current of 500mA. Strictly follow the design of PI-expert software which shall be attached, but I'm having a problem TNY275 the controller is running too warm, even with a dissipation area on the PCB as indicated by PI-expert software. I want to know what might be causing this overheating causing the controller go into protection temperature.
I appreciate the attention and sorry for my bad english.

Files

TinySwitch-III_PIDesign1.uds (332.5 KB)

Comments

Can i have your schematic? I guess something is wrong and thus causes the thermal issue.

Regards

Dear, Here my schematic.

Your schematic looks ok, but PLS check the follow three:

1. Make sure the polarity of C1,C5 and C6 are right.

2. Double check the primary snubber. Make sure the Voltage rating of the TVS is higher than Vor. And if possible use the RCD snubber.

3. Use bias winding to reduce the loss caused by high voltage shunt regulator inside the part.

Regards