Average current mode PFC control at 200 kHz
The Texas Instruments UC3854N is a power factor correction (PFC) controller operating in average current mode, switching at 200 kHz. This control topology continuously monitors the average inductor current against a sinusoidal reference, producing a low-distortion current waveform that tracks the line voltage — the dominant approach for PFC stages above 300 W where THD and EMI matter. The 14.5 V to 30 V supply range means the bias rail can be derived from an auxiliary winding or a separate regulator without tight tolerance. Startup current is 1.5 mA, which sets the minimum current the startup resistor must deliver before the auxiliary winding takes over — a key number for sizing the bootstrap resistor and the VCC hold-up capacitor.
Through-hole DIP package and commercial temperature grade
Housed in a 16-pin DIP with 0.300-inch (7.62 mm) body width, the UC3854N uses the standard 16-PDIP footprint. Through-hole mounting suits prototyping, low-volume production, and boards where rework access matters — the pin pitch allows hand-soldering and probe attachment without a fixture. It is intended for controlled indoor environments — telecom rectifiers, server PSUs, and industrial power supplies with forced airflow — not for extended-temperature or sealed enclosures where internal heating pushes the ambient above 70°C.