LT3485-0/LT3485-1/ LT3485-2/LT3485-3 Photoflash Capacitor Chargers with Output Voltage Monitor and Integrated IGBT Drive DESCRIPTIO FEATURES The LT 3485 family of photoflash chargers are highly inte- Integrated IGBT Driver grated ICs containing complete charger and IGBT drive Voltage Output Monitor functions. The patented control technique of the LT3485-x Uses Small Transformers: 5.8mm 5.8mm 3mm allows it to use extremely small transformers. Output voltage Operates from Two AA Batteries, Single Cell Li-Ion detection requires no external circuitry. The turns ratio of the or Any Supply from 1.8V up to 10V transformer controls the final charge voltage. While charging, No Output Voltage Divider Needed the output voltage on the capacitor may be monitored by a No External Schottky Diode Required microcontroller from the monitor pin. Each device contains an Charges Any Size Photoflash Capacitor on-chip high voltage NPN power switch, which can withstand Available in 10-Lead (3mm 3mm) DFN negative voltages on the switch pin without an external Fast Charge Time Schottky diode. The device features a V pin, which allows BAT VERSION INPUT CURRENT (mA) CHARGE TIME (sec) the use of two AA cells to charge the capacitor. The internal LT3485-3 750 2.5 circuitry operates from the V pin. The LT3485-0 has a IN LT3485-0 500 3.7 primary current limit of 1.4A, whereas the LT3485-3, LT3485-2, LT3485-2 350 5.5 and LT3485-1 have current limits of 2A, 1A and 0.7A respec- LT3485-1 225 4.0* tively. These different current limits result in tightly controlled V = V = 3.6V IN BAT input currents. 100F capacitor, 320V. *50F capacitor The CHARGE pin gives full control of the part to the user. U APPLICATIO S Driving CHARGE low puts the part in shutdown. The DONE pin indicates when the part has completed charging. The LT3485 Digital Camera and Cell Phone Flash Charger series of parts are housed in a leadless (3mm 3mm) DFN package. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 6636021. TYPICAL APPLICATIO LT3485-0 Photoflash Charger Uses High Efficiency 3mm Tall Transformers DANGER HIGH VOLTAGE OPERATION BY HIGH VOLTAGE TRAINED PERSONNEL ONLY V BAT 320V 1:10.2 LT3485-0 Charging Waveform 2 AA OR 1 4 1 TO 2 Li-Ion 4.7F 1M 2 5 150F A 2.2F PHOTOFLASH V SW BAT 600V CAPACITOR DONE V OUT TRIGGER T FLASHLAMP 50V/DIV CHARGE 1 GND 3 2 LT3485-0 V TO CC C V IN V MONT 5V MICRO AVERAGE IGBTPWR 0.22F INPUT CURRENT 0.5A/DIV 3485 TA02 V = 3.6V 1s/DIV IGBTIN IGBT IN IGBTOUT C = 100F OUT 3485 TA01 34850123fb 1 U ULT3485-0/LT3485-1/ LT3485-2/LT3485-3 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW V Voltage .............................................................. 10V IN V Voltage ............................................................ 10V BAT 10 CHARGE 1 V MONT SW Voltage ................................................... 1V to 50V V 2 9 DONE BAT 11 V 3 8 IGBTPWR IN SW Pin Negative Current ...................................... 0.5A SW 4 7 IGBTIN CHARGE Voltage...................................................... 10V SW 5 6 IGBTOUT IGBTIN Voltage ........................................................ 10V DD PACKAGE IGBTOUT Voltage ..................................................... 10V 10-LEAD (3mm 3mm) PLASTIC DFN DONE Voltage .......................................................... 10V T = 125C = 43C/W JMAX JA IGBTPWR Voltage.................................................... 10V EXPOSED PAD (11) IS GND, MUST BE SOLDERED TO PCB V Voltage ......................................................... 10V MONT ORDER PART NUMBER DD PART MARKING Current into DONE Pin ............................... 0.2mA/1mA LT3485EDD-0 LBRH Maximum Junction Temperature .......................... 125C LT3485EDD-1 LBVN Operating Temperature Range (Note 2) ... 40C to 85C LT3485EDD-2 LBVP Storage Temperature Range .................. 65C to 125C LT3485EDD-3 LBTK Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: