Power Factor Correction is a technique of shaping input current to be as sinusoidal as possible to reduce harmonic distortion and associated losses and in-phase with input voltage in an AC circuit to have a power factor close to one.
Placed as a front-end in a switch mode power supply (SMPS), a single-phase power factor corrector can be designed with a number of different topologies to meet specific requirements. A simple boost converter topology can be used when operating in discontinuous or continuous modes depending on power level. An interleaving architecture with two or more small interleaved stages is also useful to help achieve higher power densities. Or to further enhance efficiency of the combined PFC and rectifier front-end, bridgeless PFC topologies have emerged that can help reduce conduction loss by minimizing the number of semiconductor switches in the line-current path. For high-power systems with higher current, both Continuous Conduction Mode (CCM) and Transition mode (TM) operations are required and a new patented approach with fixed off-time (FOT) operation can provide great advantages.
ST's extended offer of PFC controllers support the simplest boost-based implementation to the more advanced digital controllers supporting interleaved and bridgeless topologies. To help design robust and high-efficient PFC stages, these devices embed all the required protection features including output overvoltage, brown-out, feedback disconnection and boost inductor saturation.
Developers will also appreciate our power MOSFETs and rectifiers in addition to a range of hardware and software evaluation and development tools.