SIC977XB is a high-precision LED constant-current control chip,the IC utilizes Quasi-Resonant (QR) Buck

topology with active PFC control for high PF,low THD,and high efficiency.

SIC977XB integrates internal demagnetization detection circuit and 650V power MOSFET with high voltage

startup,which eliminates auxiliary winding for power supply and demagnetization and simplifies the design and production cost of the system.The IC adopts accurate current sensing, close loop constant current control to achieve high precision CC control with excellent line and load regulation.

The SIC977XB has multi-protection functions which largely enhance the safety and reliability of the system,including,short-circuit protection,LED open protection,cycle-by-cycle current limit and over-temperature protection.

 Active PFC for High power factor and low THD

 Built-in HV Power Supply Circuit

 650V high voltage MOSFET integrated

 No VDD/COMP Capacitor Design

 High Output Current Accuracy<±3%

 Excellent Line and Load Regulation

 Quasi-Resonant (QR) Buck topology

 Ultra low start up & operating current

 Leading Edge Blanking (LEB)

 Output Over Voltage Protection(OVP)

 Cycle by Cycle Current Limit (OCP)

 Thermal Fold-back (OTP)

 LED Open and Short Protection