This tiny DC-DC boost converter (step-up) generates a 5V output voltage from a very small input voltage of >0.9V. The extremely low start-up voltage makes it possible to use a single AA or AAA battery (for example) to power a 5V device, or micro controller project. The output current depends on the input voltage, and a very low input voltage of just about 0.9V delivers an output current of <100mA at 5V. With 1 battery 1.5V, the max. output current is already about 250mA. With 2 batteries (3V) the max. output current reaches already about 500mA, and 600mA are possible with a single cell 3.7V lithium battery. – The efficiency is max. 96%, depending on input voltage and output current. – The max. output current is 600mA, depending on input voltage. Please do your math and understand the relation between supply current, supply voltage, and output current: For example, an output current of 450mA means an output power of 2.25W. If you have an input voltage of 3.7V, the input current is about (2.25W / 3.7V / 96% =) 635mA.