I am trying to test the IC : LT 3033. It has a linear regulator with a internal reference voltage of 0.2V. I had set feedback resistors of 150K and 11k to expect an output of 2.9V approx. However I am getting an output voltage of 0.48V at a supply of 4.5V. Also the output voltage is increasing with increase in input voltage. I am attaching the datasheet and a zip file of board and schematic files that I have created in Autodesk eagle 9.1.
There are no input/output capacitors in your schematic. The minimum output capacitor is 10uF for LT3033, and a 10uF cap is needed at the input. Remove C2 that is in parallel with the bottom feedback resistor to keep the system stable.
Yes I have not shown them in the schematic, however on the PCB I have connected capacitors between input and ground and output and ground. Also I haven't connected the capacitor in parallel to the bottom feedback resistor. I have left that open ie there is no capacitor in parallel to the lower feedback capacitor. Still the system fails to give desired output.
Are the capacitors placed close to the IC? What's the load current?
The IC is working now. I had messed up the values of the capacitors.