B. Discontinuous Conduction Mode
When the power converter is operated at the DCM, the
inductor current decreases from the peak to zero, during S has
been turned off. The duty-ratio for decreasing the inductor
current is denoted by d’. Then, the relationship between the
two input voltage and the output voltage can be obtained as
The input current ratio at the DCM can be obtained by
substituting (9) into (7).