PFC controller for offline supplies
The Texas Instruments UC3854ADW is a power factor correction (PFC) controller operating in average current mode, switching at 200 kHz. It is designed to shape the input current waveform of an offline AC-DC supply to follow the line voltage, keeping total harmonic distortion low and power factor near unity. The 10V to 20V supply range lets it run off a standard auxiliary winding or a downstream regulator without a separate bias supply.
200 kHz switching — inductor sizing and EMI
Switching at 200 kHz.
Average current mode control senses the average inductor current over each switching cycle.
The UC3854ADW comes in a 16-SOIC wide-body package (7.50 mm body width) for surface-mount assembly.
No second source or direct replacement is recorded in the manufacturer's cross-reference; the part is sole-sourced from Texas Instruments. For production builds, qualifying the BOM around a single source is standard practice for this generation of PFC controllers — no pin-compatible alternate exists from another vendor.