Single-inductor multiple-output switching converters in PCCM with freewheel switching

Many electronic applications require multiple regulated supply voltages to cater for needs from the different function modules inside. A new single-inductor multiple-output (SIMO) switching converter is designed to operate in pseudo-continuous conduction mode (PCCM) with free wheel switching, and can efficiently handles such needs. Existing SIMO switching converter work either in continuous conduction mode (CCM) or discontinuous conduction mode (DCM). CCM SIMO converters suffer from cross-regulation problems and possible negative inductor current at light loads. DCM SIMO converters have large peak currents and are not suitable for large loads. By employing freewheel switching control, this new PCCM SIMO converter can handle large stress at heavy loads with a smaller peak current while retaining low cross-regulation. It therefore solves the problems associated with previous designs. Flexibility to work in DCM at light load is also added to this design to retain high efficiency. The reliability and noise immunity of the system are thus greatly improved