LTC3490ES8#PBF Analog Devices

LTC3490 Single Cell 350mA LED Driver FEATURES DESCRIPTIO 350mA Constant Current Output The LTC 3490 provides a constant current drive for 1W 2.8V to 4V Output Compliance LED applications. It is a high efficiency boost converter 1- or 2-Cell NiMH or Alkaline Input that operates from 1 or 2 NiMH or alkaline cells and Synchronous Rectification: Up to 90% Efficiency generates 350mA of constant current with up to 4V of Fixed Frequency Operation: 1.3MHz compliance. It contains a 100m NFET switch and a Low Quiescent Current: <1mA 130m PFET synchronous rectifier. The fixed switching Very Low Shutdown Current: <50A frequency is internally set to 1.3MHz. Open LED Output Limited to 4.7V The LTC3490 limits the output voltage to 4.7V if the output V Range: 1V to 3.2V IN load is disconnected. It also features an analog dimming Dimming Control capability that reduces the drive current proportional to Undervoltage Lockout to Protect Batteries the CTRL/SHDN pin voltage. A low-battery logic output Low Profile (0.75mm) 3mm 3mm Thermally signals when the battery has dropped below 1V/cell. An Enhanced 8-Lead DD and S8 Packages undervoltage lockout circuit shuts down the LTC3490 U when the battery voltage drops below 0.85V/cell. The APPLICATIO S feedback loop is internally compensated to minimize com- Portable Lighting ponent count. Rechargeable Flashlights , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATIO Efficiency vs V at V = 3.5V Single Cell Minimum Component LED Driver IN LED 100 3.3H I = 350mA OUT 90 80 V SW IN 70 CAP 60 ON/OFF LTC3490 1 NiMH OR 50 350mA + ALKALINE 4.7F 40 CTRL/SHDN LED CELL 30 HIGH CELLS LOBAT CURRENT 1M 20 LED GND 10 0 3490 TA01 1 1.5 2 2.5 3 V (V) IN 3490 TA02 3490fa 1 EFFICIENCY (%) U ULTC3490 ABSOLUTE AXI U RATI GS (Note 1) Supply Voltage (V ) ................................... 0.3V to 6V Operating Temperature Range (Note 2) .. 40C to 85C IN Input Voltages (CTRL/SHDN, CELLS) ......... 0.3V to 6V Storage Temperature Range ................. 65C to 125C Output Voltages (CAP, LED, SW)................ 0.3V to 6V Lead Temperature (Soldering, 10 sec, S8) .......... 300C PACKAGE/O RDER I FOR ATIO TOP VIEW TOP VIEW CELLS 1 8 CTRL/SHDN CELLS 1 8 CTRL/SHDN V 2 7 LOBAT IN V 2 7 LOBAT 9 IN SW 3 6 CAP SW 3 6 CAP GND LED 4 5 GND LED 4 5 DD PACKAGE S8 PACKAGE 8-LEAD (3mm 3mm) PLASTIC DFN 8-LEAD PLASTIC SO T = 125C, = 43C/ W (NOTE 4) JMAX JA T = 125C, = 150C/ W (NOTE 4) JMAX JA EXPOSED PAD (PIN 9) IS GND MUST BE SOLDERED TO PCB (NOTE 5) ORDER PART NUMBER DD PART MARKING ORDER PART NUMBER S8 PART MARKING LTC3490EDD LBRQ LTC3490ES8 3490 Order Options Tape and Reel: Add TR Lead Free: Add PBF Lead Free Tape and Reel: Add TRPBF Lead Free Part Marking: