The operating mode of the controller is determined through the FCB pin. For boost operation, the FCB mode pin can select among Burst Mode operation, Discontinuous mode and Forced Continuous mode. During buck operation, the FCB mode pin can select among Skip-Cycle mode, Discontinuous mode and Forced Continuous mode. Burst Mode operation and Skip-Cycle mode provide high efficiency operation at light loads while Forced Continuous mode and Discontinuous mode operate at a constant frequency. Fault protection is provided by an output overvoltage comparator and internal foldback current limiting. A Power Good output pin indicates when the output is within 7.5% of its designed set point.