NCP1608BOOSTGEVB(#2): 400V @ 100W, 85 ~ 264VAC in

The NCP1608 is a voltage mode power factor correction (PFC) controller designed to implement converters to comply with line current harmonic regulations. The device operates in critical conduction mode (CrM) for optimal performance in applications up to 350 W. Its voltage mode scheme enables it to obtain near unity power factor (PF) without the need for a line-sensing network. The output voltage is accurately controlled with an integrated high precision transconductance error amplifier. The controller also implements a comprehensive set of safety features that simplify system design.

This application note describes the design and implementation of a 400 V, 100 W, CrM boost PFC converter using the NCP1608. The converter exhibits high PF, low standby power dissipation, high active mode efficiency, and a variety of protection features.

Most electronic ballasts and switch−mode power supplies (SMPS) use a diode bridge rectifier and a bulk storage capacitor to produce a dc voltage from the utility ac line. This causes a non-sinusoidal current consumption and increases the stress on the power delivery infrastructure. Government regulations and utility requirements mandate control over line current harmonic content. Active PFC circuits are the most popular method to comply with these harmonic content requirements. System solutions consist of connecting a PFC pre−converter between the rectifier bridge and the bulk capacitor (Figure 1). The boost converter is the most popular topology for active PF correction. It produces a constant output voltage and consumes a sinusoidal input current from the line.