The LT3751 is a high input voltage capable flyback controller designed to rapidly charge a large capacitor to a user-adjustable high target voltage set by the transformer turns ratio and three external resistors. Optionally, a feedback pin can be used to provide a low noise high voltage regulated output.The LT3751 has an integrated rail-to-rail MOSFET gate driver that allows for efficient operation down to 4.75V. A low 106mV differential current sense threshold voltage accurately limits the peak switch current. Added protection is provided via user-selectable overvoltage and undervoltage lockouts for both VCCand VTRANS. A typical application can charge a 1000μF capacitor to 500V in less than one second.The CHARGE pin is used to initiate a new charge cycle and provides ON/OFF control. TheDONEpin indicates when the capacitor has reached its programmed value and the part has stopped charging. TheFAULTpin indicates when the LT3751 has shut down due to either VCCor VTRANSvoltage exceeding the user-programmed supply tolerances.ApplicationsHigh Voltage Regulated SupplyHigh Voltage Capacitor ChargerProfessional Photoflash SystemsEmergency StrobeSecurity/Inventory Control SystemsDetonators