General Description

The HV9931 is a fixed frequency PWM controller IC designed to control an LED lamp driver using a single-stage PFC buckboost-buck topology. It can achieve a unity power factor and a very high step-down ratio that enables driving a single high-brightness LED from the 85-264VAC input without a need for a power transformer. This topology allows reducing the filter capacitors and using non-electrolytic capacitors to improve reliability. The HV9931 uses open-loop peak current control to regulate both the input and the output current. This control technique eliminates a need for loop compensation, limits the input inrush current, and is inherently protected from input under-voltage condition.

Features

►Constant output current

►Large step-down ratio

►Unity power factor

►Low Input current harmonic distortion

►Fixed frequency or fi xed off-time operation

►Internal 450V linear regulator

►Input and output current sensing

►Input current limit

►Enable, PWM and phase dimming

Applications

►Offl ine LED lamps and fi xtures

►Street lamps

►Traffi c signals

►Decorative lighting