Digital current sharing method for mulitiphase DC-DC converters using the peak input voltage

This paper describes a new digital current sharing method to overcome the inaccuracy of the current sensing circuitry for multiphase dc-dc converters. The difference between sensed current values causes the unequal current distribution in multiphase dc-dc converters even though they are controlled by the same current reference. The proposed digital minimum peak voltage tracking (MPVT) algorithm calculates the required current reference adjustment value using only the peak input ripple voltage information without an additional input current sensing circuit. The MPVT algorithm achieves the equal current distribution between phases of the converter with high parameter insensitivity. For the experimental verification, a 500W two phase interleaved synchronous buck dc-dc converter with 30-42V input range and 24V (20A) output is implemented.