LT3518 LED driver circuits not working

The Manufacturer Product Numberis LT3518EFE#PBF.

I powered on the circuits and the LED driver started to smoke. Something must have a short circuit somewhere, how to test and fix?

The circuits are the typical application (Buck Mode 1.5A LED Driver) in the data sheet of LED driver.



Welcome to the Technical Forum. Unfortunately this one would be hard to answer. The first thing I would do is to check the solder traces on the board to make sure that nothing is bridged or damaged. I found a good design guide from Texas Instruments that might help. Here is the link:

I am not sure if that will help, but there was a lot of useful informaation. It is very hard to say what is wrong and why the part smoked. Though I would check the circuit again and make sure it is correct.

Verna’s suggestion of a careful visual inspection is a good start; look for accidental shorts, opens, components installed backwards, incorrect components installed, etc.

Check to make sure that the circuit on the board is the same one that’s on the schematic and also the same one that’s in your mind. Things tend to go poorly when the three are not in agreement, and errors in layout or schematic capture are easy enough to make. Check everything and assume nothing; silly mistakes like connecting power backwards happen frequently.

It’s mentioned above that the example circuit from p.13 of the datasheet was followed; such examples tend to be well thought out, but do on rare occasions contain errors. Any changes in component selection however may have had an unexpected effect, and should be evaluated.