Document 529 Flyback Transformer The D1766-AL multiple-output transformer was developed for use with Linear Technology LTC4267 Power over Ethernet IEEE 802.3af PD Interface with Integrated Switching Regulator. It is ideal for use in telecommunications isolated converters and isolated power supplies. voltage of 36 – 72 Volts. It features interleaved primary and secondary windings to minimize leakage inductance and 1500 Vrms isolation between windings. Coilcraft can also custom engineer a transformer to meet your specific requirements. For free evaluation samples, contact Coilcraft or visit www.coilcraft.com. This low-profile transformer is designed for an input Part number1 Inductance at 0 Adc2 ±10% (µH) Inductance at Ipk3 min (µH) 221 200 D1766-AL_ Leakage Inductance4 max (µH) DCR max (Ohms) 0.420 (pins 1 – 3) 0.013 (pins 8 – 5) 0.013 (pins 7 – 6) 0.015 (pins 10 – 9) 0.030 (pins 12 – 11) 1. When ordering, please specify packaging code: D1766-ALD Packaging: D = 13″ machine-ready reel. EIA-481 embossed plastic tape (175 parts 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. For Linear Technology LTC4267 PoE PD Interface 5.1 Turns ratio pri : S1 pri : S2,S3 9.6 : 1 24 : 1 Ipk3 (A) 1.5 Outputs 3.3 V, 0.5 A 2.5 V, 1.5 A 1.8 V, 2.5 A 2. Inductance is for the primary, measured at 200 kHz, 1.1 Vrms, 0 Adc. 3. Peak primary current drawn at minimum input voltage. 4. Leakage inductance is for the primary and is measured with secondary windings shorted. 5. Operating temperature range –40°C to +125°C. 6. Electrical specifications at 25°C. 12 3.3 V 1 Dot indicates pin 1 1 Primary 12 S3 11 10 2.5 V 3 0.810 max 20,57 D1766-AL 6 S2 9 8,7 1.8 V 7 1.181 max 30,00 S1 5,6 GND 0.450 max 11,43 Pins 9,8,7 to be connected on the board. Pins11,10 to be connected on the board. 0.084 2,13 0.004 /0,10 0.969 24,6 0.827 21,0 6 0.028 7 0,72 0.130 3,30 0.930 23,62 1 0.050 1,27 Recommended Land Pattern 1 12 0.118 3,0 0.118 3,0 Weight: 12.7 g Terminations: Tin-silver over tin over nickel over phos bronze Tape and reel: 175/13″ reel, 44 mm tape width For packaging data see Tape and Reel Specifications section. Specifications subject to change without notice. Please check our website for latest information. © Coilcraft, Inc. 2008 Document 529 Revised 09/11/06