When sourcing PFC (Power Factor Correction) controllers, you must prioritize topology compatibility (Transition Mode, Continuous Conduction Mode, or Interleaved PFC) based on your power requirements. Key metrics include a wide input voltage range (typically 85V-265V AC), low Total Harmonic Distortion (THD < 10%), and a high Power Factor (PF > 0.95). Ensure the IC features integrated protection circuits such as Over-Voltage Protection (OVP), Over-Current Protection (OCP), and Brown-out protection to ensure long-term system reliability.