EFFICIENCY (%) LT3751 High Voltage Capacitor Charger Controller with Regulation FEATURES DESCRIPTION n Charges Any Size Capacitor The LT 3751 is a high input voltage capable flyback con- n Low Noise Output in Voltage Regulation Mode troller designed to rapidly charge a large capacitor to a n Stable Operation Under a No-Load Condition user-adjustable high target voltage set by the transformer n Integrated 2A MOSFET Gate Driver with Rail-to-Rail turns ratio and three external resistors. Optionally, a feed- Operation for V 8V back pin can be used to provide a low noise high voltage CC n Selectable 5.6V or 10.5V Internal Gate Drive regulated output. Voltage Clamp The LT3751 has an integrated rail-to-rail MOSFET gate n User-Selectable Over/Undervoltage Detect driver that allows for efficient operation down to 4.75V. n Easily Adjustable Output Voltage A low 106mV differential current sense threshold volt- n Primary or Secondary Side Output Voltage Sense age accurately limits the peak switch current. Added pro- n Wide Input V Voltage Range (5V to 24V) CC tection is provided via user-selectable overvoltage and n Available in 20-Pin QFN 4mm 5mm and 20-Lead undervoltage lockouts for both V and V . A typical CC TRANS TSSOP Packages application can charge a 1000F capacitor to 500V in less than one second. APPLICATIONS The CHARGE pin is used to initiate a new charge cycle and provides ON/OFF control. The DONE pin indicates n High Voltage Regulated Supply when the capacitor has reached its programmed value and n High Voltage Capacitor Charger the part has stopped charging. The FAULT pin indicates n Professional Photoflash Systems when the LT3751 has shut down due to either V or n CC Emergency Strobe V voltage exceeding the user-programmed supply n TRANS Security/Inventory Control Systems tolerances. n Detonators All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. Patents including 6518733 and 6636021. TYPICAL APPLICATION DANGER HIGH VOLTAGE OPERATION BY HIGH VOLTAGE TRAINED PERSONNEL ONLY Load Regulation and Efficiency T1 D1 1:10 V 500V TRANS 500 90 24V 0 TO 150mA + 330F 10F 40.2k 2 2 + 100F 498 84 RV TRANS 18.2k 0.47F OFF ON CHARGE RDCM 40.2k CLAMP RV OUT 496 78 V CC V CC LT3751 24V 10F HVGATE TO DONE LVGATE V CC MICRO FAULT 494 72 CSP 374k UVLO1 6m V TRANS 475k OVLO1 CSN 715k 492 66 374k UVLO2 FB OUTPUT VOLTAGE V CC 475k OVLO2 EFFICIENCY 1.74k GND RBG 10nF 490 60 0 50 100 150 732 LOAD CURRENT (mA) 3751 TA01b 3751 TA01a 3751fd 1 For more information www.linear.com/LT3751 OUTPUT VOLTAGE (V)LT3751 ABSOLUTE MAXIMUM RATINGS (Note 1) V , CHARGE, CLAMP ..............................................24V Current into RV Pin ........................................ 10mA OUT CC DONE, FAULT ............................................................24V Current into RDCM Pin......................................... 10mA LVGATE (Note 8) .......................................................24V Current into UVLO1 Pin .......................................... 1mA V LVGATE .............................................................8V Current into UVLO2 Pin.......................................... 1mA CC HVGATE ................................................................Note 9 Current into OVLO1 Pin .......................................... 1mA RBG, CSP, CSN ...........................................................2V Current into OVLO2 Pin .......................................... 1mA FB ..............................................................................5V Maximum Junction Temperature .......................... 125C Current into DONE Pin ........................................... 1mA Operating Temperature Range (Note 2).. 40C to 125C Current into FAULT Pin ........................................... 1mA Storage Temperature Range .................. 65C to 150C Current into RV Pin....................................... 1mA TRANS PIN CONFIGURATION TOP VIEW TOP VIEW RV 1 20 RDCM TRANS UVLO1 2 19 NC 20 19 18 17 OVLO1 3 18 RV OUT OVLO1 1 16 RV OUT 4 UVLO2 17 NC UVLO2 2 15 NC OVLO2 5 16 RBG OVLO2 3 14 RBG 21 21 FAULT 6 15 HVGATE FAULT 4 13 HVGATE DONE 5 12 LVGATE DONE 7 14 LVGATE CHARGE 6 11 V CHARGE 8 13 V CC CC CLAMP 9 12 CSP 7 8 9 10 FB 10 11 CSN FE PACKAGE 20-LEAD PLASTIC TSSOP UFD PACKAGE 20-PIN (4mm 5mm) PLASTIC QFN T = 125C, = 38C/W JMAX JA EXPOSED PAD (PIN 21) IS GND, MUST BE SOLDERED TO PCB T = 125C, = 43C/W JMAX JA EXPOSED PAD (PIN 21) IS GND, MUST BE TIED TO PCB