The SEPIC converter has a topology that is similar to the Cuk converter. The major difference is that the position of the output diode and inductor has been transposed. The output power is still transferred through the series capacitor, therefore a good quality capacitor that is capable of carrying the full load current is required. When the switch is turned on energy builds up in the input inductor and the energy that was previously stored in the capacitor is transferred to the output inductor. When the switch is turned off the energy stored in the input inductor is transferred to the capacitor and the energy in the output inductor is transferred to the load and output capacitor.

• Move the red time line to observe how the current flows in the circuit.
• Change the duty cycle to change the output to input voltage ratio.
• Adjust the load current to observe how the current levels change.