To create a functional buck converter, you will need to add these peripheral components around the LM2596: Typically 470µF to stabilize input.

To simulate circuits using this buck regulator, you must manually add an updated library file. This guide provides a complete walkthrough for downloading, installing, and simulating the LM2596 in Proteus. Why You Need an Updated LM2596 Library

You should see the component appear, likely named "LM2596-ADJ" or "LM2596 Module". Select it, click OK, and place it in your workspace. Common Issues & Troubleshooting

Paste them directly into the folder identified in Step 2.

C:\Program Files (x86)\Labcenter Electronics\Proteus 7 Professional\LIBRARY Copy and Paste the Files Extract the downloaded ZIP file to your desktop. Copy both the LM2596.LIB and LM2596.IDX files.