DC804B-A

DC804B-A demonstration circuit is a Power over Ethernet PD interface with integrated switching regulator featuring the LTC4267. It provides a complete IEEE 802.3af power device (PD) interface and isolated 3.3V power supply solution for use in PoE applications. The LTC4267 integrates 25kohm signature resistor, classification current source, thermal overload protection, signature disable and power good signal along with an undervoltage lockout optimized for use with the IEEE required diode bridge. The precision dual level input current limit allows the LTC4267 to charge load capacitors and interface with legacy PoE systems. It provides a complete IEEE 802.3af power device interface and isolated 3.3V power supply solution for use in PoE applications. LTC4267 integrates the 25kohm signature resistor, classification current source, thermal overload protection, signature disable and power good signal along with an undervoltage lockout optimized for use with the IEEE required diode bridge.

• 1A maximum output current (Vout=3.3V), 400mA maximum input current
• 250V DC isolation voltage