LT3750 Capacitor Charger Controller FEATURES DESCRIPTIO Charges Any Size Capacitor The LT 3750 is a flyback converter designed to rapidly Easily Adjustable Output Voltage charge large capacitors to a user-adjustable target volt- Drives High Current NMOS FETs age. A patented boundary mode control scheme* mini- Primary-Side SenseNo Output Voltage Divider mizes transition losses and reduces transformer size. The Necessary transformer turns ratio and two external resistors easily Wide Input Range: 3V to 24V adjust the output voltage.* A low 78mV current sense Drives Gate to V 2V accurately limits peak switch current and also helps to CC Available in 10-Lead MS Package maximize efficiency. With a wide input voltage range, the U LT3750 can operate from a variety of power sources. A APPLICATIO S typical application can charge a 100F capacitor to 300V in less than 300ms. Emergency Warning Beacons Professional Photoflash Systems The CHARGE pin gives full control of the LT3750 to the Security/Inventory Control Systems user. The DONE pin indicates when the capacitor has High Voltage Power Supply reached its programmed value and the part has stopped Electric Fences charging. Detonators , LTC and LT are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. *Protected by U.S. Patents, including 6518733, 6636021. TYPICAL APPLICATIO 300V, 6A Capacitor Charger T1 D1 1:10 V V TRANS OUT 300V 6A Charge Time 56F 10F 2 + 300 100F V = 18V TRANS V 250 TRANS 60.4k V CC V = 6V V RV CC OUT TRANS 12V 100k 200 10F 43k V = 12V TRANS DONE RDCM 150 LT3750 OFF ON CHARGE GATE M1 100 SOURCE 50 GND RBG 12m 0 0 0.1 0.2 0.3 0.4 0.5 2.49k 100pF TIME (SECONDS) 3750 TA03c 3750 TA01a 3750fa 1 V (V) OUT U ULT3750 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW V , V , GATE, DONE, CHARGE ...................... 24V CC TRANS V 1 10 RBG TRANS RBG ....................................................................... 1.5V DONE 2 9 RV OUT CHARGE 3 8 RDCM SOURCE ................................................................... 1V V 4 7 GATE CC GND 5 6 SOURCE Current into RDCM Pin ........................................ 1mA MS PACKAGE Current into RV Pin ........................................ 1mA OUT 10-LEAD PLASTIC MSOP Current into DONE Pin ......................................... 1mA T = 125C, = 120C/ W JMAX JA Operating Temperature Range (Note 2) .. 40C to 85C ORDER PART NUMBER MS PART MARKING Storage Temperature Range ................ 65C to 150C LT3750EMS LTBQD Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: