The Pololu step-up/step-down voltage regulator S7V8F3 is a switching regulator (also called a switched-mode power supply (SMPS) or DC-to-DC converter) that uses a buck-boost topology. It takes an input voltage from 2.7 V to 11.8 V and increases or decreases the voltage to a fixed 3.3 V output with a typical efficiency of over 90%. The input voltage can be higher than, lower than, or equal to the set output voltage, and the voltage is regulated to achieve a steady 3.3 V.

This flexibility in input voltage is especially well-suited for battery-powered applications in which the battery voltage begins above the desired output voltage and drops below the target as the battery discharges. Without the typical restriction on the battery voltage staying above the required voltage throughout its life, new battery packs and form factors can be considered.

For example:

In typical applications, this regulator can deliver up to 1 A continuous when the input voltage is higher than 3.3 V (stepping down). When the input voltage is lower than 3.3 V (stepping up), the available current decreases as the difference between the voltages increases