MAXREFDES108#: 12V @ 1A, 36 ~ 57V in, POE

Power over Ethernet (PoE) provides power to Ethernet connected devices, through Ethernet lines, eliminating the need for connecting AC mains to the target devices. In addition to reducing cabling, PoE provides multiple advantages for many applications such as LED lighting, cameras, sensors and additional equipment. These advantages include network management of devices, power measurement, and elimination of AC/DC circuitry.

Many PoE applications are isolated, to protect both people and systems from voltage and current transients. However, many applications do not require isolation, such as LED lighting and other equipment generally out of range for human touch. In these cases, eliminating the isolation circuitry further reduces cost and power dissipation at the PoE point of load. MAXREFDES108# is a unique PoE module reference design, providing 12V at 1A (12W) from a 36V to 57V input. This design can be used for evaluation, design, prototyping and production.

MAXREFDES108# includes two function blocks: the PD controller block and the step down DC-DC power supply block. The PD controller uses the MAX5969A. The MAX5969A is an IEEE® 802.3af compliant, powered device interface controller with an integrated power MOSFET. The DC-DC power supply uses the MAX17505. The MAX17505 is a 4.5V~60V input, 1.7A output, high-efficiency synchronous step down converter with internal compensation. The entire design delivers a peak efficiency of 90% with an input of 48V.

The MAXREFDES108# features 12 through-hole pins spaced at a 2.54mm pitch standard. This modular architecture allows MAXREFDES108# to be soldered into a PCB or inserted into the MAXREFDES98EV# for evaluation.