Efficiency measuring circuit for DC-DC converter which calculates internal resistance of switching inductor based on duty cycle

摘要

An efficiency measuring circuit may measure the efficiency of a DC-DC converter having a switching inductor with an internal DC resistance and a plurality of electronic switches that control current through the inductor. A duty cycle circuit may measure the duty cycle of current flowing through one of the electronic switches. A current sense circuit may measure the current flowing through one of the electronic switches. An inductor voltage sensor circuit may measure the voltage across the inductor. A computation circuit may compute the internal DC resistance of the switching inductor based in part on the duty cycle measured by the duty cycle circuit and the current measured by the current sense circuit. The computation circuit may also compute the efficiency of the DC-DC converter.