NCP1611ADR2G

The NCP1611ADR2G is an enhanced high-efficiency Power Factor Controller 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 NCP1611 linearly decays the frequency down to about 20kHz 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, internal circuitry allows near-unity power factor even when the switching frequency is reduced. The circuit also incorporates the features necessary for robust and compact PFC stages, with few external components.

• Near-unity power factor
• Critical conduction mode (CrM)
• Skip mode near the line zero crossing
• Fast line /load transient compensation
• Valley turn on
• Low startup consumption
• Line range detection
• Configurable for low harmonic content across wide line/load range
• Brown-out detection
• Over current limitation