The TPS61291DRVT is a Low Iq Boost Converter with an integrated bypass mode and pin selectable output voltages. In bypass operation, the device provides a direct path from the input to the system and allows a low power micro controller (MCU) such as the MSP430 to operate directly from a single 3V Li-MnO2 battery or dual alkaline battery cells. In bypass mode the integrated feedback divider network for boost mode operation is disconnected from the output and the quiescent current consumption drops down to only 15nA (typical). Bypass mode or boost mode operation is controlled by the system via the EN/BYP pin. The device integrates an enhanced bypass mode control to prevent charge, stored in the output capacitor during boost mode operation, from flowing back to the input and charging the battery. In boost mode, the device provides a minimum output current of 200mA at 3.3V VOUT from 1.8V VIN.