LM3447 Phase Dimmable, Primary Power Regulated, PFC Flyback Controller for LED Lighting
【产品特性】．Supports All Common Line Voltages
．Meets Regulatory PFC Requirements for LED Lighting
．Improved Dimmer Compatibility with Wide Dimming Range and Flicker-Free Performance
．Compact Design with Low Component Count
．Improved Line and Load Regulation
．Protects Against Fault and Abnormal Operating Conditions
【产品应用】．Dimmable A19, R20, PAR30/38 LED Lamps
．Recessed LED Downlights and Pendent Lights
．Industrial and Comercial Solid State Lighting
【文字介绍】The LM3447 is a versatile power factor correction (PFC) controller designed to meet the performance requirements of residential and commercial phase-cut dimmer compatible LED lamp drivers. The device incorporates a phase decoder circuit and an adjustable hold current circuit to provide smooth, flicker free dimming operation. A proprietary primary side control technique based on input voltage feedforward is used to regulate the input power drawn by the LED driver and to achieve line regulation over a wide range of input voltage. Valley switching operation is implemented to minimize switching loss and reduce EMI. An internal thermal foldback circuit is provided to protects the LEDs from damage based on the temperature sensed by a single external NTC resistor. Additional features include LED open circuit and short circuit protection, cycle-by-cycle FET over-current protection, burst mode fault operation using an internal 812ms fault timer and internal thermal shutdown.
The LM3447 is ideal for implementing dimmable, isolated single stage LED lamp drivers where simplicity, low-component count and small solution size are of primary importance. This device is currently available in a TSSOP 14-pin package.