The AP61040CP6-7 from Diodes Incorporated is a Low-Current Synchronous Buck Converter that converts an input voltage of 2.15-5.5 V to an output voltage of 0.6-5.5 V. It provides an output current of 400 mA and has a quiescent current of 930 nA to maximize light-load efficiency. This DC-DC converter provides high efficiency, excellent transient response, and high DC output accuracy. It has a switching frequency of 1.1 MHz and provides three programmable output voltages between 0.6V to 3.3V, selectable by one selection pin. This buck converter has a low external component count with outstanding performance in line/load transient response and seamless transition between buck and 100% duty cycle modes. It features undervoltage lockout (UVLO), short-circuit, overtemperature protection (OTP), and overcurrent protection (OCP) to protect the circuit. This converter is available as a wafer that measures 1.220 x 0.820 x 0.500 mm and is ideal for wearables such as fitness trackers, smart watches, health monitors, Bluetooth low-energy devices, ultra-low power applications, and energy harvesting solutions.