The NCL2801 is a current mode CRM Boost PFC control IC which can provide the best class THD performance over extended operating range utilizing ON Semiconductor’s THD enhancer technique. Efficiency and standby power are enhanced with Valley Count Frequency Fold-back (VCFF) method.Valley Count Frequency FoldbackDynamic Response EnhancerSoft/Fast OVPTHD EnhancerLine level feed-forwardProtections - Brown Out - Thermal Shutdown - OVP - Over Current limitation - Pin open/short protectionWide Vcc (10.5∼28 V) range/ 3 Vcc startup levelOTA Error AmpMaximize efficiency over wide load rangeLower output undershootLower output overshootImprove THD performanceOptimal loop gain in universal inputHigh System ReliabilityDesign FlexibilityEasy loop design and lower power loss by higher RFBApplicationsAll Off Line Appliances Requiring Power Factor CorrectionEnd ProductsLighting Ballasts (LED, Fluorescent)Flat TVPC Power Supplies