Buck-Boost Converters: SEPIC & Four-Switch Topologies Explained

How buck-boost converters keep the output regulated whether input voltage is above or below the target rail.

A buck-boost converter regulates the output whether the input sits above or below the target rail. This makes it invaluable in automotive, energy-storage, portable and industrial systems where the input voltage swings widely.

Two proven topologies

  • SEPIC — continuous output current and a simple, robust design for moderate power.
  • Four-switch BUCK-BOOST — highest efficiency across the full range, using four switches and an inductor.

EVEVSPOWER implementation

Our buck-boost modules accept inputs up to 120V, recover output within 10ms under input transients, and are built on imported control chips for reliability. Constant-current buck-boost chargers with automatic full-charge cutoff are available for battery applications. Browse the family.