7805 Voltage Regulator IC Circuit Working and Applications Apr 11, 2018Has both internal current limiting and thermal shutdown features. Requires very minimum external components to fully function. Pin Diagram of 7805 Voltage Regulator IC. As mentioned earlier, 7805 is a three terminal device with the three pins being 1. INPUT, 2. GROUND and 3. OUTPUT. The following image shows the pins on a typical 7805 IC in To-220 Package.