The TPS62770 is a tiny power solution for wearable applications including a 370nA ultra low Iq step-down converter, a slew rate controlled load switch and a dual mode step-up converter. The output voltage of the step-down converter can be selected with three VSEL pins between 1.0 V, 1.05 V, 1.1 V, 1.2 V, 1.8 V, 1.9 V, 2.0 V and 3.0 V. The output voltage can be changed during operation. In shutdown mode, the output of the step-down converter is pulled to GND. The integrated load switch is internally connected to the output of the step-down converter and features slew rate control during turn on phase. Once turned off, its output is connected to GND. The dual mode step-up converter can generate a constant output voltage up to 15 V, such as PMOLED supply; or, a constant output current, such as LED back light supply. The output voltage can be adjusted up to 15 V with external resistors, or set to fixed 12 V by connecting the FB pin to VIN. The device features an internal over voltage protection of 17.7 V in case the FB node is left open or tight to GND. It includes an internal rectifier and load disconnect function. When used as constant output current driver, the device offers a PWM to analog converter to scale down the reference voltage according to the duty cycle of the PWM signal. The device is available in a small 16pin 0.4mm pitch WCSP package.