DCM Conversion Characteristics

Correct Answer

C — Statement-1 is False, but Statement-2 is True

Concept and Reasoning

In discontinuous conduction mode, the inductor current becomes zero during part of each switching period. The conversion ratio then depends on load resistance as well as duty ratio and circuit parameters, and the current ripple is not independent of load. Hence the statement combination specified by option C is correct.

Calculation / Key Relation

DCM gain = f(D, R, L, fs), unlike ideal CCM gain

Exam Takeaway

DCM introduces load dependence into converter gain.

Common Mistake

Do not apply the simple CCM conversion ratio in DCM.