一种无乘法器的小功率PFC芯片电路设计_6_10.pdfVIP

ABSTRACT ABSTRACT With the rapid development of electronic technology, more and more electrical equipments are connected to the power network.So that the harmonic current will be introduced in the AC power supply system. However the harmonic currents will cause a lot of negative problems, such as voltage distortion, thermal noise, and reduction of the capability of the power energy transmission line. Power Factor Correction is an effective technique for improving this problem. This thesis focuses on the demands of the small power market, using TSMC 1μm 24V processes for the design of XW8201, which is a power factor correction chip worked in a critical conduction mode. First, this thesis has outlined the PFC technology principle and the development, and then several basic APFC circuit’s topologies are intrduced, and a detailed analysis and comparison of circuit control mode for two APFCs with common critical conduction mode are presented. Based on the analysis above, the system design, circuit design, and simulation have been completed. With a boost CRM active power factor correction, the electric current is automaticly followed with voltage. The prominent advantages of proposed design are that the chip is achieved without the traditional circuits input voltage multiplier circuit and the sampling circuit, and the chip size and complexity are greatly reduced. In view of the shortcoming of the traditional power factor correction chip in slow transient response, the multi-output vector error amplifier is developed with low band width filter function and the fast smooth output transient response ability. Moreover an optimized electric c