DESCRIPTION
PT6909 is a fixed frequency PWM controller IC designed to control high brightness LED driver using a single-stage PFC boost-buck topology. It can achieve a well power factor and a higher dc-bus voltage. This topology allows reducing the filter capacitors and using non-electrolytic capacitors to improve reliability. The PT6909 uses open-loop peak current control technique eliminates a need for loop compensation, limits the input inrush current, and is inherently protected from input under-voltage condition.

FEATURES
• Simple Power factor Correction Integrated
• Low Start-up Current
• 8V to 12V Input Range
• Constant –Current Driver
• Programmable Fixed Frequency Operation
• Input and Output Current Sensing
• Input Current Limit
• Boost Circuit Over-Voltage Protection(LED Open Protection)
• Input Voltage Limitation
• Low Input Current Harmonic Distortion
• PWM Low-Frequency Dimming and Phase Dimming Compatible

APPLICATIONS
• LED Replacement Tube
• AC/DC LED Driver
• LED Lamp with Phase Dimmable
• Street lamps
• Traffic signals