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 kHz fixed frequency, pulse-width-modulation (PWM) controller using a synchronous rectifier to obtain maximum efficiency. The maximum peak current in the boost switch is limited to 1000 mA (TPS61058) and 1500 mA (TPS61059).The converter can be disabled to maximize battery life. In the shutdown mode, the load is completely disconnected and the current consumption is reduced to less than 1 µA.