DEMO MANUAL DC2125 LT4275, LT4321, LTM8027 Small Highly-Integrated Highly-Efficient Non-Isolated PoE Powered Device Description Demonstration circuit 2125 is a small, highly-integrated, compliant Type 2 (25.5W, at) or Type 1 (13W, af) PD ++ non-isolated PoE Powered Device (PD) solution. It features by changing the RCLASS and RCLASS resistors. See a PD Interface Controller (LT 4275), which interfaces with the LT4275 data sheet for further information. The output a PoE Power Sourcing Equipment (PSE), an ideal diode voltage of the LTM8027 can be easily configured for differ- bridge controller (LT4321), which minimizes bridge losses, ent output voltages as shown in the LTM8027 data sheet. and a DC/DC Module regulator (LTM 8027). Gerber files for this circuit board are available. Call ++ The DC2125 is initially configured as a 38.7W LTPoE the LTC factory. PD that is capable of providing 12V and 3A at the output. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Users can configure the PD circuit to be an IEEE802.3 p s Specifications are at T = 25C A SYMBOL CONDITIONS UNITS V RJ-45 Port Voltage Range 37V to 57V PORT + I Maximum Current from V to V 3A OUT(MAX) OUT OUT V Output Voltage 12V (typ) OUT V Output Voltage Ripple at V = 50V, I = 3A 58mVpp (typ) OUT(RIPPLE) PORT OUT V Output Voltage Regulation, I = 0A to 3A, V 0.031% (typ) OUT(REG) OUT PORT Efficiency Maximum Efficiency, V = 41V, I = 3A 90% (typ) PORT OUT f Switching Frequency 300kHz (typ) SW Boar D p Top Side Bottom Side dc2125f 1 hotos ummary erformanceDEMO MANUAL DC2125 t p c Top Side Bottom Side Figure 1. Thermal Pictures V = 50V, I = 3A PORT OUT Efficiency and Regulation dc2125f 2 haracteristics erformance ypical