This applet explores how the switching and conduction losses are influenced by the operating parameters of the circuit and the choice of semiconductor device.
Conduction losses are caused when current flows through the switching device and a voltage drop is caused due to its internal resistance. Therefore the amount of conduction losses are dependent on the current level in the device (load current level), the time the device is conducting (in other words the duty cycle), and the on-resistance of the device.
Switching losses occur whenever a device switches on and switches off. This is because the voltage across the device and the current in the device do not change instantaneously. The switching power loss usually is represented as a triangular shape since the voltage and current change in first approximation in a linear way.

• Observe the turn-on and the turn-off switching transition by shifting the “zoom” box on the waveforms.
• Change the MOSFET’s on-resistance value by adjusting the size of the structure's top layer (click and drag) and observe the change in the conduction and switching losses.
• Change the load current by varying the load resistance and observe the change in the conduction and switching losses.
• Change the duty cycle and observe the impact on the losses.
• Change the switching frequency and observe the changes in the conduction and switching losses.