MAXREFDES128#: No optocoupler isolation, PoE, 48V to 5V, 12.5W flyback power supply

To meet the increasing demands for isolated Power over Ethernet (PoE) power solutions, Maxim’s power supply experts have developed innovative, isolated, PoE, powered device (PD) power solutions. These isolated PoE power solutions efficiently convert high voltage PoE power into 5V and 12V outputs, respectively. Each design was tested for load and line regulation, as well as efficiency and transient performance. These boards feature a module architecture, with through-hole pins for immediate board placement and accelerated prototyping.

The MAXREFDES128# combines the PD controller and an efficient no-opto flyback topology with 48V input and a 5V output at 12.5W of power (2.5A). The design features the MAX5969A (powered device interface controller with integrated power MOSFET), MAX17690 (a peak-current-mode converter with flexible switching frequency), and the MAX17606 (a secondary-side MOSFET driver for flyback converter). This entire circuit fits on a 25.4mm (1in) x 64.8mm (2.55in) board.

As with all Maxim reference designs, the BOM, schematics, layout files, and Gerber files can be found on the Design Resources tab.

This board is not available for purchase.

Features

• 36V to 57V input voltage
• Compact and flexible
• Minimal external components
• Robust operation in adverse environments
• 12.5W output capacity
• ±3% output accuracy

Applications

• Lighting
• IP cameras
• Sensors
• Isolated Ethernet equipment