Coilcraft GA3271-AL Flyback Transformer for Maxim MAX5941B PWM Controller
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SMT Flyback Transformer
for Power over Ethernet

  • Developed for Maxim MAX5941B PoE Interface/PWM Controller
  • Designed for 13 W PoE applications
  • 30 – 60 V input; 12 V, 1.0 A output
  • 1500 Vrms, one minute primary to secondary isolation
  • 15 V, 20 mA bias winding output
  • RoHS-compliant. 260°C compatible. Tin-silver (96.5/3.5) over tin over nickel over phos bronze terminations


Part number1
Click to get parts
at 0A2
±10% (µH)
at Ipk3
±5% (µH)
DCR max4
max (µH)
Turns ratio6 Ipk3
pri : sec pri : bias
GA3271-AL_ 117.5 104.0 0.201 (pri)
0.06 (sec)
0.335 (bias)
0.815 1 : 0.457 1 : 0.571 1.0 12 V, 1.0 A
1 When ordering, please specify packaging code: e.g. GA3271-ALD
  Packaging: D = 13" machine-ready reel
EIA 481 embossed plastic tape (200 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.
2 Inductance is for the primary, measured at 250 kHz, 1.0 Vrms.
3 Ipk: Peak primary current drawn at minimum input voltage.
4 DCR for the primary and secondary are measured with the windings connected in parallel. DCR measured at 25°C. For other operating temperatures, use this DCR at Temperature calculator.
5 Leakage inductance is for the primary winding with the secondary windings shorted.
6 Turns ratios are for the primary and the secondary windings connected in parallel. 
7 Output of the secondary is with the windings connected in parallel. Bias winding output is 15 V, 20 mA.
8 Ambient temperature range: −40°C to +125°C
9 Storage temperature range: Component: −40°C to +125°C
Tape and reel packaging: −40°C to +80°C
10 Resistance to soldering heat: Three reflows at >217°C for 90 seconds (+260°C ±5°C for 20 – 40 seconds), allowing parts to cool to room temperature between.
11 Electrical specifications at 25°C.
Refer to Soldering Coilcraft Components before soldering.
PCB washing: Tested to MIL-STD-202 Method 215 plus an additional aqueous wash. More info

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Updated: April 16, 2018