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 PT4209-Primary Side Offline LED Controller with Active PFC  PDF文档下载 GENERAL DESCRIPTION The PT4209 is a flicker-free PWM/analog dimmable, primary side constant current controller which can achieve high power factor in a single stage converter, targeted to applications in solid state lighting. It is designed for the flyback topology, and regulates output current accurately without the secondary feedback loop. PT4209 works in quasi-resonant mode to reduce the MOSFET switching loss. The device uses extremely low startup and low quiescent current to achieve high efficiency. A complete set of integrated protection functions allows the PT4209 to protect against all fault conditions such as VCC under-voltage, VCC over-voltage, cycle by cycle current limit, output open/short circuit, Rcs open circuit, transformer winding short circuit and over temperature shut down.
 The PT4209 is available in SOP8 package.
 FEATURES Constant Current Control Without Secondary Feed back
  Flicker-free PWM/analog Dimming (10%-100%)
  Accurate Constant Current Output
  Quasi-Resonant Mode Operation
  Ultra-low(10uA)Start Up Current
  Low Quiescent Current (1mA)
  VCC Under Voltage Protection
  Over Voltage Protection by Voltage Holding
  Cycle by Cycle Current Limit
  Rcs Open Circuit Protection
  Transformer Winding Short Circuit Protection
  Output Open/Short Circuit Protection
  Over Temperature Protection
 
 APPLICATIONS Solid State Lighting
  Industrial and Commercial Lighting
  Residential Lighting
 
 
 
 
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