Reference Design for a Powered-Device (PD) Module Based on the MAX5941B PWM Controller

This application note provides a reference design for an IEEE 802.3af-compliant, 12.95W adjustable-output powered-device module. Assembled on a 12cm² printed circuit board (PCB), the module is based on the MAX5941B PWM controller and includes hot-swap power switching, a DC-DC converter, and a pair of ORing diode bridges for compatibility with an external 12V adapter. This application note details the performance of the module and provides a schematic, a PCB layout, and a components list for the design.