• Primary Side CV Control Eliminates the Optocoupler
• Valley Turn-on of the Primary MOSFET to Achieve Low Switching Losses
• Integrate THD Compensation, PF>0.9, THD<20% during 40% Load to 100% Load
• Fast Load Regulation
• Internal High Current MOSFET Driver: 0.1A Sourcing and 0.5A Sinking
• Maximum Switching Frequency Limitation 100kHz
• Compact Package: SO8

The SY5018C is a single stage Flyback and PFC controller targeting at Constant Voltage (CV) applications. The primary side control is applied to reduce the feedback circuit cost. It drives the Flyback converter in the Quasi-Resonant mode for the high efficiency and achieves the high-power factor by a constant on-time control scheme. The adaptive PWM/PFM control is adopted for the highest average efficiency. It integrates the THD compensation to achieve the higher PF and lower THD.