LED Driver with Power Factor Correction, Primary-Side-Regulated

The FL7733A is a highly-integrated PWM controller with advanced Primary-Side Regulation (PSR) technique to minimize components in low-to-mid-power LED lighting converters. Using an innovative TRUECURRENT® technology to provide tight tolerance constant-current output, this LED driver enables designs with constant current (CC) tolerance of less than ±1% over the universal line voltage range to meet stringent LED brightness requirements. By minimizing turn-on time fluctuation, high power factor and low THD over the universal line range are obtained in the FL7733A. An integrated high-voltage startup circuit implements fast startup and high system efficiency. During startup, adaptive feedback loop control anticipates the steady-state condition and sets initial feedback condition close to the steady state to ensure no overshoot or undershoot of LED current.The FL7733A also provides powerful protections, such as LED short / open, output diode short, sensing resistor short / open, and over-temperature for high system reliability. The FL7733A controller is available in an 8-pin Small-Outline Package (SOP).