Lecture 08 Buck Converter CCC-DCM

What are the two main operational modes of a DC-DC converter?

• BCM and DCM

• CCM and BCM

• CCM and DCM

• DCM and ACM

In a Buck Converter, what happens to the inductor current waveform in Continuous Current Mode (CCM)?

• Reaches zero before one cycle

• Does not reach zero before one cycle

• Fluctuates rapidly

• Becomes constant

Which of the following is a characteristic of Discontinuous Current Mode (DCM)?

• Inductor current never reaches zero

• Higher output voltage ripple

• Lower output voltage ripple

• Inductor current is continuous

What happens to the inductor ripple current when the inductance is reduced?

• Decreases

• Remains the same

• Increases

• Becomes zero

What is the effect of increasing load resistance in a Buck Converter?

• Increases the inductor current

• No change in operational mode

• Operational mode shifts from CCM to DCM

• Decreases the output voltage

How is the critical (boundary) load resistance (Rb) determined in a Buck Converter?

• Based on the maximum output voltage

• Based on the input voltage

• From the inductor current and load current ratio

• From the switching frequency

What factor primarily determines the CCM-DCM operational mode?

• Switching frequency

• Duty cycle

• Load resistance

• Inductor current waveform

What is the effect of variable duty cycle on a Buck Converter's operation?

• No effect

• Changes from DCM to CCM

• Changes from CCM to DCM

• Only changes the output voltage

Which element in a Buck Converter circuit acts as a passive switch?

• MOSFET

• Capacitor

• Inductor

• Diode

What happens to the inductor current when the switching frequency is increased?

• It decreases

• It increases

• It remains constant

• It becomes zero