ANALOG DEVICES DC2475A-A Demonstration Board, LT4295IUFD, LT4321IUF#PBF, Power Over Ethernet, Powered Device Controller

DC2475A-A is an Ethernet Alliance� certified IEEE802.3bt compliant Power over Ethernet (PoE) powered device (PD). It features the LT4295 PD interface and switching regulator controller with the LT4321 PoE ideal diode bridge controller. The LT4295 provides IEEE802.3af (PoE, Type 1), IEEE802.3at (PoE+, Type 2), and IEEE802.3bt (PoE++, Type 3 and 4) compliant interfacing and power supply control. It utilizes an external, low RDS(ON) (57Mohm typical) N-channel FET for the Hot Swap function to improve efficiency. The LT4295 controls a DC/DC converter that utilizes a highly efficient flyback topology with synchronous rectification. The LT4321 controls eight low RDS(ON) (57Mohm typical) N-channel FETs to further improve end-to-end power delivery efficiency and ease thermal design. This solution replaces the eight diodes typically found in a passive PoE rectifier bridge.

• Port voltage range from 37 to 57V at RJ45, AUX voltage from 37V to 57V (from AUX+ to AUX� terminals)
• Supplies a 12V output at up to 3A
• Typical output voltage ripple is 85mVP-P (VPORT = 44V, IOUT = 3A)
• ±0.1% (typical) load regulation
• 92% efficiency
• 250KHz (typical) switching frequency

Notes

ADI products are only authorized (and sold) for use by the customer and are not to be resold or otherwise passed on to any third party