I am looking to use the D15V35F5S3 #2111 voltage regulator to power a devices which draws 35Watts (5V at 7A). According to the specification sheet I read that the regulator has a 90% efficiency in this range meaning I will have 40W input, and the regulator will consume 5Watts.
Without any heatsink on the regulator and assuming the device will operate at room temperature, how hot will the regulator get.
First off, you have the right part number (#2111) for the 7-amp version, but you have the product name for the 3.5-amp version. Anyway, the power is limited by overheating, so at the upper limit of the output current, the module will get very hot, with the hottest parts approaching 150 degrees C. I do not know what kind of tolerance you have on that 7A load, but I would be nervous using this regulator without carefully characterizing it in your application. You should also keep in mind that the efficiency and heating distribution are not always the same.
Thanks for the quick reply.
From what I’ve calculated, my application will use 6.66A at 5V which is hopefully the worst case. Normal operating conditions should be lower, I am expecting around 4A.
But you’ve answered my real question which is I should probably add a heatsink to the regulator.