Description

This reference design is a four-switch, buck-boost DC/DC converter used for battery backup unit (BBU) applications, targeting Open Compute Project® (OCP) Open Rack V3 Power BBU specifications. This design has a 12KW power capability. The converter works in either buck, buck-boost, or boost mode depending on the V_in and V_out voltage. The converter transitions smoothly between each mode. Peak current mode control is employed in this design, providing a fast load transient response. Relying on the LM51770 features, no extra driver is needed for field-effect transistors. This design has a total of six phases; among them, six phases are connected in parallel for battery discharging operation, provide up to 12KW discharging power.