NCP1612 - Enhanced, High Efficiency Power Factor Controller

The NCP1612 is designed to drive PFC boost stages based on an innovative Current Controlled Frequency Fold−back (CCFF) method. In this mode, the circuit classically operates in Critical conduction Mode (CrM) when the inductor current exceeds a programmable value. When the current is below this preset level, the NCP1612 linearly decays the frequency down to about 20 kHz when the current is null. CCFF maximizes the efficiency at both nominal and light load. In particular, the stand−by losses are reduced to a minimum. Like in FCCrM controllers, an internal circuitry allows near−unity power factor even when the switching frequency is reduced. Housed in a SO−10 package, the circuit also incorporates the features necessary for robust and compact PFC stages, with few external components.