Fairchild – FAN9673: High Power PFC Control in Half the Space


High power applications, such as motor drives for white goods, welders and electric vehicle charging, require Power Factor Correction (PFC) to improve PF, harmonics and to avoid deteriorating the power grid. The design challenges involved include the size and cost of inductors, capacitors, higher power semiconductor devices and the need for a costly current transformer. Now these challenges can be easily met with the FAN9673—the industry’s first 3- channel interleaved CCM PFC controller.

The interleaved 3-channel design reduces input current ripple, capacitor RMS current and heat dissipation. Results include greater efficiency, power density and stability—and most important—significant cost and size savings. Comparing a single non-interleaved solution to the 3-channel FAN9673, a 61% inductor size reduction can be realized. Interleaved operation also makes EMI filtering easier and more cost effective.

An innovative channel management function allows the power level of the slave channels to be loaded/unloaded smoothly according to the setting voltage on the CM pin, improving the load transient response. The FAN9673 also incorporates a variety of protection features including peak current limiting, input voltage brown out protection and TriFault Detect™ technology to protect against feedback loop failure.

Altogether, the FAN9673 enables designers to develop simple, compact and cost effective systems, with greater efficiency and stability, for applications up to 9kW.

The FAN9673Q is available in a 32-Lead, Low Quad Flat Package (LQFP), 7mm2


  • Enabling the use of smaller passive components—up to 61% reduction in inductor size
  • Lower component costs
  • Greater power density
  • Higher efficiency
  • Greater stability

  • High power AC/DC power supply
  • DC motor drives
  • White goods
  • Server and telecom equipment
  • UPS
  • Industrial welding
  • Electronic vehicle charging