MAXREFDES138#: No optical isolation, PoE, 48V to 12V, 12W 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 12V 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 MAXREFDES138# combines the PD controller and an efficient no-opto flyback topology with 48V input and a 12V output at 12W of power (1A). The design features the MAX5969A (powered device interface controllers with integrated power MOSFET), MAX17690 (a peak-current-mode converter with flexible switching frequency), and the MAX17606 (a secondary-side MOSFET driver for a flyback converter). This entire circuit fits on a 25.4mm (1in) x 55.8mm (2.2in) board.

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