Auto-tuning scheme for improved current sharing of multiphase DC-DC converters

In this study, an auto-tuning scheme is presented to realise simple and accurate calibration, for improved current sharing in multiphase DC-DC converters. The proposed control scheme is based on a look-up table method to automatically tune the pre-stored parameters to obtain the same effect as equal output inductance and direct current resistor (DCR). It ensures that time constant is perfectly matched in a conventional DCR current-sensing technique. The proposed scheme provides a low-cost solution with ease of implementation because it is fully designed using a digital control technique without any external phase compensation elements. The proposed scheme is verified on a two-phase interleaved DC-DC buck converter with a 12-V input and a 1-V, 40-A output. Simulation and experimental results are presented to demonstrate the theoretical analysis.