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. Rated for 0°C to 70°C commercial environments, this part fits controlled indoor power supplies, server PSUs, and telecom rectifiers where ambient temperature stays within that band.
200 kHz switching — inductor sizing and EMI
Switching at 200 kHz.
Average current mode — what it means for the loop
Average current mode control senses the average inductor current over each switching cycle.
Package and mounting
The UC3854ADW comes in a 16-SOIC wide-body package (7.50 mm body width) for surface-mount assembly.
Lifecycle and compliance
The UC3854ADW is listed as Active with no end-of-life notification. It is ROHS3 compliant, so it meets the current EU restriction on hazardous substances without an exemption. 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.