The ISL9120IR is a highly efficient buck-boost converter for low power applications needing less than an amp of output current. It comes in a tiny 3 mm x 3 mm TQFN package and only requires three external components to create a regulated 3.3 V output. Like the ISL91107IR and ISL91127IR that will be discussed in a moment, the ISL9120IR accepts inputs from 1.8 V to 5.5 V and can create a regulated output from 1.0 V to 5.2 V. As the battery voltage input drops to near the required output, the ISL9120IR will automatically switch to bypass mode and maximize battery life.