When the input voltage is above the UVLO rising threshold and the EN pin is pulled to a voltage above 1.2 V, the TPS61022 is enabled and starts up. At the beginning, the TPS61022 charges the output capacitors with a current of about 700 mA when the output voltage is below 0.4 V. When the output voltage is charged above 0.4 V, the output current is changed to having output current capability to drive 1-Ω resistance load. After the output voltage reaches the input voltage, the TPS61022 starts switching, and the output voltage ramps up further. The typical start-up time is 700 µs accounting from EN high to output reaching target voltage for the application with input voltage is 2.5 V, output voltage is 5 V, output effective capacitance is 30 µF and no load. When the voltage at the EN pin is below 0.4 V, the internal enable comparator turns the device into shutdown mode. In the shutdown mode, the device is entirely turned off. The output is disconnected from input power supply.