Document 423 PoE Transformer For National Semiconductor LM5070 PoE Interface This surface mount flyback transformer was developed specifically for the National Semiconductor LM5070 Powered Devices Interface in 13 Watt Power over Ethernet (PoE) applications. It is designed to operate at frequencies up to 1 MHz with an with an input voltage of 36 – 72 Volts. Output with the secondary windings connected in parallel is 3.3 V, 4.5 A. Isolation is 1500 Vrms from the primary and auxiliary windings to the secondary. Coilcraft can design custom transformers with voltage, inductance and DCR values to meet your specific requirements. For free evaluation samples, contact Coilcraft or order them on-line at www.coilcraft.com. DCR max (Ohms)4 Part L at 0 A2 L at Ipk3 1 number ±10% (µH) ±10% (µH) pri aux sec C1023-AL_ 110 99.0 0.139 0.656 0.016 Leakage L (µH)5 1.40 1. When ordering, please specify a packaging code: C1023-ALD Packaging: D = 13″ machine ready reel. EIA-481 embossed plastic tape (175 per full reel). B = Less than full reel. In tape, but not machine ready. To have a leader and trailer added ($25 charge), use code letter D instead. 2. Inductance is for the primary, measured at 10 kHz, 0.1 Vrms, 0 Adc. Dot indicates pin 1 0.028 0,711 1 0.130 3,30 6 0.930 23,62 0.050 1,27 Recommended Land Pattern Pri Sec 6 9 8 7 1 0.118 3,0 0.118 3,0 Aux 3 Secondary windings to be connected in parallel on PC board. 0.450 max 11,43 0.827 21,00 0.969 24,60 0.004 /0,10 Weight: Terminations: Tape and reel: 12.4 g Tin-silver over tin over nickel over phos bronze 175/13″ reel, 44 mm tape width Specifications subject to change without notice. Please check our website for latest information. © Coilcraft, Inc. 2008 4 12 11 10 7 1.181 max 30,00 0.080 2,03 Capacitance7 Ipk3 Isolation8 (pF) (A) (Vrms) 70 1.5 1500 3. Ipk is the peak current drawn at minimum input voltage. 4. DCR for the secondary is per winding. 5. Leakage inductance is for the primary winding with all other pins shorted. 6. Turns ratio is with the secondary windings connected in parallel. 7. Capacitance measured between pins 3 and 4 with other pins shorted. 8. Isolation is measured from the primary and aux to the secondary. 9. Operating temperature range –40°C to +85°C. 10. Electrical specifications at 25°C. 1 12 C1023-AL 0.810 max 20,57 Turns ratio6 pri : sec pri : aux 1 : 0.19 1 : 0.69 Document 423 Revised 10/25/06