LT3751 Datasheet | Linear Technology

LT3751 High Voltage Capacitor Charger Controller with Regulation Features nn Charges Any Size Capacitor nn Low Noise Output in Voltage Regulation Mode nn Stable Operation Under a No-Load Condition nn Integrated 2A MOSFET Gate Driver with Rail-to-Rail Operation for VCC ≤ 8V nn Selectable 5.6V or 10.5V Internal Gate Drive Voltage Clamp nn User-Selectable Over/Undervoltage Detect nn Easily Adjustable Output Voltage nn Primary or Secondary Side Output Voltage Sense nn Wide Input VCC Voltage Range (5V to 24V) nn Available in 20-Pin QFN 4mm × 5mm and 20-Lead TSSOP Packages APPLICATIONS nn High Voltage Regulated Supply nn High Voltage Capacitor Charger nn Professional Photoflash Systems nn Emergency Strobe nn Security/Inventory Control Systems nn Detonators DESCRIPTION The LT®3751 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 106m V differential current sense threshold voltage accurately limits the peak switch current. Added protection is provided via user-selectable overvoltage and undervoltage lockouts for both VCC and 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. The DONE pin indicates when the capacitor has reached its programmed value and the part has stopped charging. The FAULT pin indicates when the LT3751 has shut down due to either VCC or VTRANS voltage exceeding the user-programmed supply tolerances. All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. Patents including 6518733 and 6636021. TYPICAL APPLICATION DANGER...