The TPS61058/9 devices are fixed frequency, synchronous boost dc-dc converters with an integrated down conversion mode. The devices are optimized for driving high power single cell white LEDs up to 800 mA from a 2.7-V to 5.5-V input. The LED current can be programmed to different levels (e.g. torch, flashlight) by a set of external resistors. The boost converter is based on a 650 frequency, pulse-width-modulation (PWM) using a synchronous rectifier to obtain efficiency. The maximum peak current in switch is limited to 1000 mA (TPS61058) mA (TPS61059).