In this applet the operating modes for a buck-boost converter operating with a regulated output voltage are examined. By changing the operating conditions the converter can be made to operate in either continuous or discontinuous current conduction mode. In this system the input voltage is variable and a controller regulates the duty cycle in order to maintain a constant output voltage. By adjusting the switching frequency and the input voltage the operating point can be shifted from discontinuous to continuous conduction mode.

• Move the red time line to see the various current paths.
• Change the input voltage below and above the output voltage to observe the change in operating mode from boost to buck.
• Adjust the load resistance and the input voltage to see how the duty cycle changes.
• Change the switching frequency and observe the change between continuous and discontinuous conduction mode.