LT3468/LT3468-1/LT3468-2 Photoflash Capacitor TM Chargers in ThinSOT FEATURES DESCRIPTIO Highly Integrated IC Reduces Solution Size The LT 3468/LT3468-1/LT3468-2 are highly integrated Uses Small Transformers: ICs designed to charge photoflash capacitors in digital and 5.8mm 5.8mm 3mm film cameras. A patented control technique* allows for the Fast Photoflash Charge Times: use of extremely small transformers. Each device contains 4.6s for LT3468 (0V to 320V, 100F, V = 3.6V) an on-chip high voltage NPN power switch. Output voltage IN 5.7s for LT3468-2 (0V to 320V, 100F, V = 3.6V) detection* is completely contained within the device, IN 5.5s for LT3468-1 (0V to 320V, 50F, V = 3.6V) eliminating the need for any discrete zener diodes or IN Controlled Input Current: resistors. The output voltage can be adjusted by simply 500mA (LT3468) changing the turns ratio of the transformer. The LT3468 375mA (LT3468-2) has a primary current limit of 1.4A, the LT3468-2 has a 1A 225mA (LT3468-1) limit, and the LT3468-1 has a 0.7A limit. These different Supports Operation from Single Li-Ion Cell, or Any current limit levels result in well controlled input currents Supply from 2.5V up to 16V of 500mA for the LT3468, 375mA for the LT3468-2 and Adjustable Output Voltage 225mA for the LT3468-1. Aside from the differing current No Output Voltage Divider Needed limit, the three devices are otherwise equivalent. Charges Any Size Photoflash Capacitor The CHARGE pin gives full control of the part to the user. Low Profile (<1mm) SOT-23 Package Driving CHARGE low puts the part in shutdown. The DONE U pin indicates when the part has completed charging. The APPLICATIO S LT3468 series of parts are available in tiny low profile Digital / Film Camera Flash (1mm) SOT-23 packages. PDA / Cell Phone Flash , LTC and LT are registered trademarks of Linear Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation. Emergency Strobe All other trademarks are the property of their respective owners. *Protected by U.S. Patents, including 6518733. TYPICAL APPLICATIO LT3468 Photoflash Charger Uses High Efficiency 4mm Tall Transformer LT3468 Charging Waveform DANGER HIGH VOLTAGE OPERATION BY HIGH VOLTAGE V = 3.6V IN TRAINED PERSONNEL ONLY C = 100F OUT 1:10.2 V IN 320V 2.5V TO 8V 1 4 4.7F 2 5 + V OUT 50V/DIV 100F V SW IN 100k AVERAGE LT3468 INPUT CURRENT DONE DONE GND 1A/DIV 1s/DIV 3468 G01 CHARGE CHARGE 346812 TA01 346812fa 1 U ULT3468/LT3468-1/LT3468-2 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) ORDER PART V Voltage .............................................................. 16V IN NUMBER SW Voltage ................................................ 0.4V to 50V TOP VIEW CHARGE Voltage...................................................... 10V LT3468ES5 SW 1 5 VIN DONE Voltage .......................................................... 10V LT3468ES5-1 GND 2 Current into DONE Pin .......................................... 1mA LT3468ES5-2 DONE 3 4 CHARGE Maximum Junction Temperature .......................... 125C S5 PACKAGE S5 PART Operating Temperature Range (Note 2) ...40C to 85C 5-LEAD PLASTIC TSOT-23 MARKING Storage Temperature Range ..................65C to 150C T = 125C JMAX = 150C ON BOARD OVER JA Lead Temperature (Soldering, 10 sec).................. 300C GROUND PLANE LTAEC = 90C/W JC LTAGQ LTBCH Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25C. V = 3V, V = V unless otherwise noted. (Note 2) Specifications A IN CHARGE IN are for the LT3468, LT3468-1 and LT3468-2 unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS Quiescent Current Not Switching 5 8 mA V = 0V 0 1 A CHARGE Input Voltage Range 2.5 16 V Switch Current Limit LT3468 (Note 3) 1.1 1.2 1.3 A LT3468-2 0.77 0.87 0.97 A LT3468-1 0.45 0.55 0.65 A Switch V LT3468, I = 1A 330 430 mV CESAT SW LT3468-2, I = 650mA 210 280 mV SW LT3468-1, I = 400mA 150 200 mV SW V Comparator Trip Voltage Measured as V V 31 31.5 32 V OUT SW IN V Comparator Overdrive 300ns Pulse Width 200 400 mV OUT DCM Comparator Trip Voltage Measured as V V 10 36 80 mV SW IN CHARGE Pin Current V = 3V 15 40 A CHARGE V = 0V 0 0.1 A CHARGE Switch Leakage Current V = V = 5V, in Shutdown 0.01 1 A IN SW CHARGE Input Voltage High 1V CHARGE Input Voltage Low 0.3 V Minimum Charge Pin Low Time HighLow High 20 s DONE Output Signal High 100k from V to DONE 3 V IN DONE Output Signal Low 33A into DONE Pin 100 200 mV DONE Leakage Current V = 3V, DONE NPN Off 20 100 nA DONE Note 1: Absolute Maximum Ratings are those values beyond which the life 40C to 85C operating temperature range are assured by design, of a device may be impaired. characterization and correlation with statistical process. Note 2: The LT3468E/LT3468E-1/LT3468E-2 are guaranteed to meet Note 3: Specifications are for static test. Current limit in actual application performance specifications from 0C to 70C. Specifications over the will be slightly higher. 346812fa 2 U WWW