Research And Design Of Power Factor Correction Circuit Based On Boost Topology

With the improvement of technical level of various power supply systems,harmonic pollution effects on power network are becoming more and more serious.People pay more attention to harmonic pollution. In order to improve power quality,meet the increasing demands of green energy and improve power utilization rate,power factor correction (PFC) has become the key of power managements.As PFCtechnology more and more widely used in power managements, electric vehicle,fluorescent lamp ballast and other fields, research on PFC techniques is becomingmore and more important. The performance requirements of power factor correctioncircuit especially its control chip is also getting higher and higher.This paper firstly analyzed basic principles of PFC. By comparing three types ofPFC topology and control strategy respectively and combining the medium-powerapplication environment, topology and strategy of the control chip were determined tobe boost and critical conduction mode (CRM). Then, based on the designed systemindex, design of PFC external circuit was conducted and inner modules of chip werealso designed. Along with stand by function and self-start circuit, the designed controlchip integrated programmable over voltage and over current protection.By pulsewidth modulation and zero-current detection, CRM and fixed output voltage can beachieved. Fabricated by0.4μm BCD technology, PFC circuit designed in this paperwas simulated, layout was designed and the chip was taped out at last.According to the simulation results of the designed PFC circuit, the input currentwas actually sinusoidal and kept in phase with input voltage, power factor achieved0.996, and under12V supply voltage, the static consumption of the chip was31mV.The area of the designed chip was1.186mm×1.172mm. Basic functions likezero-current detection, pulse width modulation and so on were tested in consistentwith the expected goal.DC parameters were tested within the designed range. Basedon the designed control chip, low boost PFC circuit test was conducted. Testingresults showed that the designed circuit functioned well.