The TPS4009x uses fixed frequency, peak current mode control with forced phase current balancing. When compared to voltage mode control, current mode results in a simplified feedback network and reduced input line sensitivity. Phase current is sensed by using either current sense resistors installed in series with output inductors or, for improved efficiency, by using the DCR (direct current resistance) of the filter inductors. The latter method involves generation of a current proportional signal with an R-C circuit (shown in Figure 10.