• 5.5%~100% Dimming Range
• CV Mode for Bias Supply at <2.5% Dimming Signal
• Primary Side Control Eliminates the Opto-coupler
• Valley Turn-on of the Primary MOSFET to Achieve Low Switching Losses
• 300mV Primary Current Sense Voltage Leads to A Lower Sense Resistance thus A Lower Conduction Loss
• Internal High Current MOSFET Driver: 0.20A Sourcing and 0.65A Sinking
• Low Start up Current: 34μA Typical
• Reliable Short LED and Open LED Protection
• Power Factor >0.90 with Single-stage Conversion.(Analog Dimming Only)
• RoHS Compliant and Halogen Free
• Compact Package: SO8

The SY22645 is a single stage Flyback and PFC controller targeting at LED Dimming applications, which can achieve up to 5.5% dimming level and high precision for all loading range. It is a primary side controller without applying any secondary feedback circuit for low cost, and drives the converter in the quasi-resonant mode to achieve higher efficiency. It keeps the converter in constant on time operation to achieve high power factor.