The SC3202 is a Power Factor Correction (PFC) controller which is applied to boost converter. It features High performance by using multi-mode control strategy. At heavy load or full load, it operates in Critical conduction Mode (CrM). When load decreases, it operates in Discontinuous Conduction Mode (DCM) with valley switching and lower frequency for high efficiency. And at no load, the IC will operate in Burst Mode to reduce power consumption and minimize audio noise. Using SC3202 together with the flyback controller and secondary synchronous rectifier controller, high efficiency over full load can be achieved, and extremely low standby power consumption of system can easily meet the efficiency regulations. Benefit from the SC3202,the PFC stage will obtain nearly unity power factor and sinusoidal line input current with few external components. SC3202 offers comprehensive protections to prevent the circuit from damage under abnormal conditions. SOT23-6/SOP8 package is provided to simplified user’s design and reduced system cost