UCC28050

Product Folder Sample & Buy Technical Documents Tools & Software Support & Community Reference Design UCC28050, UCC28051, UCC38050, UCC38051 SLUS515G – SEPTEMBER 2002 – REVISED DECEMBER 2015 UCC2805x, UCC3805x Transition Mode PFC Controller 1 Features 1 Transition Mode PFC Controller for Low Implementation Cost Industry Pin Compatibility With Improved Feature Set Improved Transient Response With Slew-Rate Comparator Zero Power Detect to Prevent Overvoltage Protection (OVP) During Light Load Conditions Accurate Internal VREF for Tight Output Regulation Two UVLO Options OVP, Open-Feedback Protection, and Enable Circuits ±750-mA Peak Gate Drive Current Low Start-Up and Operating Currents Lead (Pb)-Free Packages 3 Description The UCC38050 and UCC38051 are PFC controllers for low-to-medium power applications requiring compliance with IEC 1000-3-2 harmonic reduction standard. The controllers are designed for a boost preregulator operating in transition mode (also referred to as boundary-conduction mode or critical conduction-mode operation). They feature a transconductance voltage amplifier for feedback error processing, a simple multiplier for generating a current command proportional to the input voltage, a current-sense (PWM) comparator, PWM logic, and a totem-pole driver for driving an external FET. In the transition mode operation, the PWM circuit is self-oscillating, with the turnon being governed by an inductor zero-current detector (ZCD pin), and ...