PoE Circuit Delivers 13W to 70W for Powered Devices (PDs)

This application note presents a simple, cost-effective, pre-IEEE 802.3at PoE+ Powered Decice (PD) solution that employs the MAX5941B. The preliminary requirements of PoE+ PDs are discussed, as is the advantage of extending the existing MAX5941B circuit to implement a PoE+ PD. Test results including inrush-current limit, efficiency, output ripple, and dynamic response are presented for a 3.3V, 30W PD.