Buck-Boost Converter

Buck-boost topologies handle inputs both above and below the output — useful on AGVs when coil voltage swings with misalignment and load. Four-switch buck-boost avoids the inverted ground reference of classic inverting buck-boost.

Complexity trades against a simpler buck with wider input range and link power control limiting low-voltage episodes.

01When needed

• Wide battery voltage range (e.g., empty to full SOC) with fixed coil tuning.
• Ultracap buffers with voltage swing distinct from pack voltage.
• Dock internal rails from variable PFC bus during brownout.

02Control

Mode transitions between buck and boost regions need hysteresis or unified control to avoid oscillation. Efficiency dips near buck-boost boundary — map loss there explicitly in efficiency charts shown to customers.

03Alternatives

• Resonant frequency or phase control on transmitter to keep receiver voltage in buck-only range.
• Series regulating element when efficiency penalty is acceptable for simplicity.