If you're looking for the , here’s a concise review of your best options and how to proceed.
If your Proteus version (especially older ones like 7.10 or portable versions) does not have the component, you will need to download a library file (usually a .LIB or .IDX file). download sg3525 library for proteus better
If you cannot find a stable library, there is a workaround that advanced users love: importing a Texas Instruments SG3525 SPICE model into Proteus. SG3525 PWM controller library for Proteus If you're
Once you have the better library files, installing them correctly is critical. One wrong folder and Proteus will ignore your library. Download
.LIB and .IDX filesLIBRARY folder in Proteus installation