LTC3490 Datasheet PDF

●The LTC3490ES8#PBF is a 350mA single cell LED Driver optimized for 1W LED applications. It is a high efficiency boost converter that operates from 1 or 2 NiMH or alkaline cells and generates 350mA of constant current with up to 4V of compliance. It contains a 100m Ohm NFET switch and a 130mR PFET synchronous rectifier. The fixed switching frequency is internally set to 1.3MHz. The LTC3490 limits the output voltage to 4.7V if the output load is disconnected. It also features an analogue dimming capability that reduces the drive current proportional to the CTRL/SHDN pin voltage. A low-battery logic output signals when the battery has dropped below 1V/cell. An under-voltage lockout circuit shuts down the LTC3490 when the battery voltage drops below 0.85V/cell. The feedback loop is internally compensated to minimize component count.

● Constant current output

● 2.8 to 4V Output compliance

● 1- or 2-cell NiMH or Alkaline input

● Synchronous rectification up to 90% efficiency

● Fixed frequency operation

● Low quiescent current (<1mA)

● Very low shutdown current (<50µA)

● Open LED output limited to 4.7V

● Dimming control

● Under-voltage lockout to protect batteries