I am trying to implement a switching voltage regulator from 7.2V to 5V with LM2596 by HTC Korea. Since I don't need an adjustable regulation, I chose typical application circuit from the datasheet which is for fixed output voltage (seen below).
I use 1N5817 (20V, 1A, for testing only) Schottky diode for D1, and different values for L1 including 27uH and 33uH. I also change Cout to 100uF, 270uF, 330uF, 470uF and 1000uF (16V and 25V). No matter what I did I couldn't change output voltage. It's always around 1.25 volts, the value does not change if I remove D1, L1 or both. Changing L1 or Cout also does not affect output voltage. If I remove Cout and measure output voltage without a load, it's around 4V.
What am I doing wrong? Is there anything that I am missing here? I also attach the pictures of my test configuration on breadboard below.