A Design Of Power Factor Correction Technology LED Driver Chip

LED lighting has irreplaceable advantages, widely used in various fields such as lighting, backlighting, more and more get of people.To seek a new way of energy conservation and environmental protection lighting is more and more important. And LED lighting has its own advantages in environmental protection and energy saving, and status is becoming more and more important in all fields. The price of LED lighting is becoming more and more cheap, we can see LED lighting has applied into all fields. Experiments show that the existing LED lighting is far superior to the traditional way of lighting luminous efficiency.This paper, based on the principle of the flyback type switch power supply, and connecting with the power factor correction technology, adopt the peak current mode, constant high precision output current, output current is adjustable, 90-265 VAC input voltage range, the power factor achieve 95% or more. The static current is less than 1 mA, the current in normal working conditions is about 2 mA, the switch frequency is about 70 KHz. The chip is only six pin and peripheral circuit is very simple, greatly reduced the cost and volume. By adopting the working style of the original edge feedback without secondary output current sampling, with source factor correction circuit(APFC), can greatly improve the power factor, reduce the harmonic distortion. Using zero current detection technology, the chip work in inductor current critical continuous mode, switching loss is small, thus the overall efficiency is higher. Built-in multiple protection function to enhance system reliability, including OVP(over-voltage protection), ULVO(under-voltage protection), LED short circuit protection and open protection, OCP(the original edge over-current protection), etc.. and all the protection of the automatic has restart function.The whole circuit topology and the working principle of the various modules parameter setting, circuit design and simulation are introduced in detail, then design the circuit structure and verified it. In the final analysis various performance indicators.