Field support asked a good question so I will post it here:
Question: Won't the OUT to SET abs. max. rating be violated if OUT of the LT3080 is in overload, since SET will program one voltage but the overloaded OUT will be a lower voltage? For example, start up into a very large output capacitor may cause the LT3080 to go into overload until the large output capacitor is charged. I show the abs. max. rating from the LT3080 datasheet in the image below:
Note 7 of the LT3080 datasheet says that OUT and SET are clamped to each other with diodes. I show Note 7 in the image below. If OUT of the LT3080 is in overload and cannot regulate voltage, OUT will pull down SET because of the clamp diodes. I show that behavior below in a scope capture of an overload condition. I also show the schematic. Except for extreme conditions like a large CSET and a fast overload dv/dt, the OUT to SET current will not be enough to violate the OUT to SET abs. max. rating.
CONDITIONS: LT3080EDD, DC995A, 2.5VIN, 5VCTRL, OVERLOAD into 1 Ohm to 500mOhm to 1Ohm, VSET VOUT IOUT_0.bmp
