CX9642 PoE Flyback Transformer | Coilcraft
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CX9642 PoE
Flyback Transformer

  • Developed for Silicon Labs Si3406, Si34061, and Si34062 30 W PD Flyback POE
  • Designed  to meet 30 W PoE IEEE 802.3at-2009 standard
  • Optimized for 220 kHz with 36 – 57 input voltage, also operates from 100 kHz to 500 kHz
  • Isolation: 1500 Vrms one minute primary and auxiliary to secondary; 500 Vrms primary to auxiliary
  • RoHS-compliant. 260°C compatible. Tin-silver-copper over tin over nickel over phos bronze


Part number1
Click to get parts
L at 0 A
L at Ipk
DCR max (Ohms) Leakage
L max4
Turns ratio5 Ipk3
pri sec aux    pri : sec pri : aux
CX9642-ALD 70.0 60.0 0.08 0.0027 0.36 1.0 : 0.136 : 0.409 3.0 5.0 V, 6 A
1 When ordering, please specify packaging code: e.g. CX9642-ALD
Packaging: D = 13" machine-ready reel
EIA 481 embossed plastic tape (175 parts per full reel). Quantities less than full reel available:
in tape (not machine ready) or with leader and trailer ($25 charge).
2 Inductance is for the primary, measured at 333.3 kHz, 0.1 Vrms, 0 Adc.
3 Ipk is the peak primary current drawn at minimum input voltage.
4 Leakage inductance is for the primary winding with the secondary windings shorted.
5 Turns ratio is with the primary and the secondary windings connected in parallel.
6 Output is with the secondary windings connected in parallel. Output of the auxiliary winding is 14.5 V, 25 mA
7 Ambient temperature range: −40°C to +85°C
8 Maximum part temperature: +125°C (ambient + temp rise)
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: July 03, 2018