I've been reading some spec sheets on the LM317 and I'm confused at what it can do. Here is the PDF I've been looking at.
www.ti.com/lit/ds/symlink/lm317.pdf
Now on the first page it says under features "output current greater than 1.5a" further down it says max amperage is 1.5 and in another place it says 2.2 A.
From what I have come to believe about how these transistors work, is if a voltage of 7.5v is given to it and 5v is the output, then it wastes the 2.5v as heat. So if it was drawing 1.5 A for output, does that mean it would be drawing 1.5A * 7.5v = 11.25watts so output is 5v * 1.5A = 7.5watts Heat would = 11.25 - 7.5 = 3.75watts. Is this correct?
If I desire the same output of 5v @ 1.5A and I give it a 3.5v input would it draw 3.5v @ 2.15A and have no waste heat? I'm confused as to how much input current is allowed.
www.ti.com/lit/ds/symlink/lm317.pdf
Now on the first page it says under features "output current greater than 1.5a" further down it says max amperage is 1.5 and in another place it says 2.2 A.
From what I have come to believe about how these transistors work, is if a voltage of 7.5v is given to it and 5v is the output, then it wastes the 2.5v as heat. So if it was drawing 1.5 A for output, does that mean it would be drawing 1.5A * 7.5v = 11.25watts so output is 5v * 1.5A = 7.5watts Heat would = 11.25 - 7.5 = 3.75watts. Is this correct?
If I desire the same output of 5v @ 1.5A and I give it a 3.5v input would it draw 3.5v @ 2.15A and have no waste heat? I'm confused as to how much input current is allowed.