The inductor or capacitor values are unrealistic, or the feedback compensation is unstable. Fix:
To integrate the voltage regulator into Proteus for circuit simulation and PCB design, you will need to add external library files, as it is often missing from the standard default database. 1. Download Library Files proteus lm2596 library
: Commonly modeled in TO-220 (through-hole) and TO-263 (surface mount) footprints. How to Add the LM2596 Library to Proteus The inductor or capacitor values are unrealistic, or