Demonstration circuit 2262 is a PoE Powered Device (PD) with a synchronous forward isolated power supply featuring the LT4276 and an ideal diode bridge controller (LT4321).
The LT4276 provides IEEE802.3af (PoE, Type 1), IEEE802.3at (PoE+, Type 2), and LTPoE++ PD interfacing and power supply control. When the PD is connected to a PSE, the LT4276 turns on an external, low-resistance, high-power N-channel Hot Swap™ FET. The LT4276 controls a high-power, small-sized power supply that utilizes a highly efficient, synchronously rectified, active clamp forward topology. The LT4321 provides further efficiency improvement by minimizing bridge losses.