I was doing thru the app note written – Design Note 554 for LT3815. I’m highly impressed with this unique flyback converter and planning on using it for my upcoming design. However, I’m concerned about the temperature rise on my board if I had to use this converter at high temperature operations. I understand that LT8315HFE is rated up to 150C, but my ambient conditions would be quite high (150C). I’m looking to use the converter for about 7W load.
Having said that, I wanted to understand what would be the temperature rise within LT3815? As per the app note, for a nearly 11W power supply, the temperature rise was about 37C above ambient.
From datasheet Θjc is about 10C/W, but I believe that the temperature rise within flyback transformer is not directly proportional to the output wattage but dependent on the efficiency.
So, I wanted to know how can I determine the temperature rise for my application? Any suggestions?