Fairchild Semiconductor Minimizes Power Losses in Multi-Stage Power Supplies

Power Factor is an important measure of power quality and shows how efficiently energy is drawn from an AC source. With all PFC controllers striving to reach the ideal power factor (PF) of 1, Fairchild’s CCM PFC controller, the FAN6982, reaches near unity with 0.999 of PF at full load. With this, utility companies do not have to supply as much power to electronic applications. With power factor controllers like Fairchild's FAN6982, AC harmonic currents resulting from today's complex loads can be virtually eliminated, thereby allowing for a more efficient power distribution system.

Fairchild’s FAN6982 maintains high system efficiency at light load conditions to meet 20 percent load system efficiency requirements of ENERGY STAR® regulations and Climate Savers Computing Initiatives. It achieves this by reducing capacitive switching losses and by reducing the voltage conversion ratio, which results in less conduction losses in the boost switch.

This CCM PFC controller reduces external components and offers ease of design through its high level of integration. Features of the CCM PFC controller are: built-in brown-out protection, eliminating 12 components; adjustable PFC output, eliminating 17 components; RDY pin for power-on-sequence, eliminating 15 components; 30V operating voltage capability, eliminating 10 components; and PFC soft-start, eliminating 4 components – in total decreasing bill of materials (BOM) by 54 devices.

Since many AC-sourced electronic applications have a microphone, amplifier or loudspeaker, which need an accurate reproduction of sound, this controller offers exceptionally low Total Harmonic Distortion (4.6 percent at full load) which reduces these harmonics and meets class D requirements of IEC 1000-3-2. The FAN6982 does this through its switching-charge technology that senses input current and voltage directly, helping to improve PF and THD.

Fairchild Semiconductor provides the industry’s most comprehensive portfolio of products for AC-DC power supplies. From CCM PFC controllers to BCM PFC controllers, these solutions help electronics to achieve higher levels of efficiency, lower standby power and ease of design.