TPS54873,pdf(4-V to 6-V Input,

As a member of the SWIFT™ family of dc/dc regulators, family of dc/dc regulators,the TPS54873 low-input voltage high-output current synchronous buck PWM converter integrates all required active components. Included on the substrate with the listed features are a true, high performance, voltage error amplifier that enables maximum performance and flexibility in choosing the output filter L and C components; an under-voltage-lockout circuit to prevent start-up until the input voltage reaches 4 V; an internally or externally set slow-start circuit to limit inrush currents; and a power good output useful for processor/logic reset, fault signaling, and supply sequencing.

For reliable power up in output precharge applications, the TPS54873 is designed to only source current during startup.