This schematic details a versatile DC-DC power supply, commonly known as a buck-boost converter, engineered to accept a wide input of 3V to 30V and deliver a stable, adjustable output from 1.2V to 30V. Its key feature is the ability to regulate the output voltage regardless of whether the input is higher or lower than the desired output.

The circuit’s flexibility comes from its two-stage topology. The first stage, using an XL6009 boost controller (U1), steps up the input voltage to a consistent intermediate level. This voltage is then fed to the second stage, a robust LM2596S-ADJ (U2) buck converter. This step-down regulator precisely controls the final voltage, which is finely tuned by the user via potentiometer P2, making it ideal for battery-powered devices and applications with fluctuating power sources.