Efficiency improvement in multiphase converter by changing dynamically the number of phases

Abstract

In this paper a simple technique to improve the efficiency on multiphase converters is explored. The number of phases is dynamically changed in order to reduce power losses at light load. Theoretical considerations about the application field of this technique and the influence on the output capacitor are provided. Moreover, practical aspects such as influence of MOSFET driver and DC current sharing among phases should be taken into account. Experimental results show that this technique allows important improvements in the efficiency while maintaining satisfactory current sharing in the connection/disconnection of the phases.