The LTC3454 is a synchronous buck-boost DC/DC converter optimized for driving a single high power LED at currents up to 1A from a single cell Li-Ion battery input. The regulator operates in either synchronous buck, synchronous boost, or buck-boost mode depending on input voltage and LED forward voltage. PLED/PINefficiency greater than 90% can be achieved over the entire usable range of a Li-Ion battery (2.7V to 4.2V).LED current is programmable to one of four levels, including shutdown, with dual external resistors and dual enable inputs. In shutdown no supply current is drawn.A high constant operating frequency of 1MHz allows the use of small external components.The LTC3454 is offered in a low profile (0.75mm) thermally enhanced 10-lead (3mm × 3mm) DFN package.ApplicationsCell Phone Camera FlashCell Phone Torch LightingDigital CamerasPDAsMisc Li-Ion LED Drivers