High-Precision Active Current-Controlled Boost PFC Circuit

To address the challenges of low power factor (PF), high harmonic distortion, and poor dynamic load adaptability in hundred-watt AC-DC systems, this paper proposes a critical conduction mode (CRM) active PFC chip based on Boost topology. By integrating demagnetization detection and primary-side current sensing, the design eliminates the need for auxiliary zero-current detection (ZCD) windings, reducing circuit complexity and cost while ensuring real-time inductor current zero-crossing monitoring. The chip incorporates dual-mechanism dynamic/static over-voltage protection, multi-level safeguards cycle-by-cycle current limiting, inductor short-circuit protection, feedback loop fault handling, and over-temperature protection), and CRM/DCM switching strategies. Experimental results under 90-264 V input and 120 W output demonstrate a PF ≥ 0.95, efficiency is greater than 95% and total harmonic distortion (THD) < 6%, with enhanced stability across varying loads and voltages. This solution offers a compact, reliable, and cost-effective approach for high-power-density PD chargers, meeting stringent standards such as IEC 61000-3-2.