Coilcraft Q4434-BL Flyback Regulator Transformer
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Flyback Regulator Transformer

  • For flyback regulator applications using LM258X SIMPLE SWITCHER®
  • Recommended and approved by National Semiconductor
  • Input voltage: 4 – 6 V
  • 500 Vrms isolation between windings
  • RoHS-compliant – Tin-silver over tin over nickel over phos bronze.
  • COTS Plus tin-silver-copper and tin-lead terminations available
  • Custom versions available


ref #
Part number
Click for
L at
0 Adc
±15% (µH)
L at Ipk
min (µH)
max (Vµsec)
max (µH)
DCR (Ohms)2 Turns
Output Ipk3
Pri Sec
T1 Q4434-BL 22 19.8 162.0 2.0 0.028 0.028 1 : 1 5 V, 1.6 A 5.0
1 Leakage inductance measured across the primary at 0.10 Vrms, 100 kHz.
2 DCR measured at 25°C. For other operating temperatures, use this DCR at Temperature calculator.
3 DC current at which the primary inductance is measured.
4 Ambient temperature range: −40°C to +85°C
5 Storage temperature range: Component: −40°C to +85°C
Packaging trays: −40°C to +80°C
6 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