I used the the both model, the fix(3.3V and 5.0V) and adjustable output voltage with the same footprint, the enable signal in common. but, the adjustable one worked, the other didn't. the adjust one give the expected output while with the fix, the output is equal to the input voltage (6.0V). I tried both case, do not place the feedback resistor and do place the fb resistor. they are the same results, the output is equal to the input. so, anyone can help me, plz.?