Based On The Crm Model Type Boost Pfc The Research And Design Of The Controller

When the electronic equipment was power supplied by the commercial power, to get a steady voltage, it is often the case that a bridge rectifier and a large capacitor are needed, than a DC-DC converter may be used after the bridge to obtain the specific voltage that was needed, unless a PFC circuit was added, the circuit described above has a very low power factor, which can severely deteriorate the loading capability of the power supply system.There are several methods of power factor correction, but they can be rated into two large kinds, one is called the passive power factor correction, the other is called the active power factor correction. Passive power factor correction has the short coming of needing large discrete components, like large capacitor, also the passive power factor correction fails to get a high PF like above0.95. Active power factor correction overcomes the short coming mentioned above, it has a small volume, better reliability and can achieve PF above0.95.This article start from the basic conception of PFC, the study several different circuit topology and control strategy. The Boost power factor controller operates in the CRM mode has a simple topology, and is specifically suitable for application which has a low power dissipation (below400W). in this article, a Boost power factor controller operates in the CRM mode was designed, the module circuit of the IC were designed and simulated with the BCD0.5um technology. The simulate result displays that the controller has proper function.