The white LED launched linear synchronous step-up DC/DC converter

Corporation launched synchronous step-up DC/DC converter LTC3490 optimized for driving high current white LED. LTC3490 to work efficiency as high as 90%, to prolong the battery run time, and the input voltage range of 1V to 3.2V so that it can be from a single or double alkaline / NIMH provides current up to 350mA. The output voltage range from 2.8V to 4V is fully in line with the forward voltage requirement of high current LED. LTC3490 provides constant current drive for applications requiring up to 1W LED power. 3mm x 3mm DFN package (or SO-8) and 1.3MHz switching frequency so that it can provide solutions for handheld applications for slim board area.

When the output load disconnect, LTC3490 can set the output voltage is limited to 4.7V, so as to enhance the reliability of system. The on-chip analog dimming function is proportional to the CTRL/SHDN pin voltage to reduce the LED drive current. The low battery logic output indicates that the battery voltage has been reduced to less than 1V, and when each section is 0.85V, the undervoltage lockout circuit turns off the LTC3490 to enhance the protection. LTC3490 offers the most compact 1W LED driver solution for portable lighting and rechargeable flash applications.

LTC3490 are available in stock, using 3mm x 3mm DFN or SO-8 package. In 1000 pieces for the bulk purchase, each price starts at $2.10.

Performance overview: LTC3490

350mA constant current output 2.8V to 4V output range to meet the requirements of 1 - or 2 Ni MH metal or alkaline battery input - synchronous rectification efficiency: - fixed frequency operation up to 90% 1.3MHz - low static current: < 1mA - low shutdown current: < 50uA - open circuit LED output limit to 4.7V - VIN range: 1V to 3.2V dimming control, undervoltage lockout to protect the battery - flat (0.75mm) 3mm x 3mm thermally enhanced 8 lead DD and S8 packages