Coilcraft Q3903-AL Toroidal Transformer
Inductor Finders Power  |   RF
Power Magnetics Tools
RF Inductor Tools
CM Choke \ Ferrite Beads
LC Filter Designer
IC / Inductor Match Tool
Application Notes
Other Resources
Designer's Kits

Q3903-AL Toroidal Transformer

  • Specified by ON Semiconductor for use with their NCP1605 PFC Controller.
    Referenced as X25, pulse transformer on evaluation board NCP1605FORWGEVB and
    Application Note AND8292.
  • Recommended by Texas Instruments for use with their UC3875 Phase Shift Resonant Controller.
  • Three 1 : 1 windings
  • 500 Vrms, one minute winding-to-winding isolation.
  • RoHS-compliant Tin-silver over tin over nickel over brass.
  • COTS Plus tin-silver-copper and tin-lead terminations available
  • Custom versions available


Part number
Click to get parts
min (µH)
DCR max2
isolation (Vrms)
Q3903-AL 210 0.090 500
1 Inductance measured between pins 1 and 6, at 15.75 kHz, 0.015 Vrms, 0 Adc using an Agilent/HP 4192A impedance analyzer or equivalent.
2 DCR is per winding, measured at 25°C on a Cambridge Technology micro-ohmmeter or equivalent. For other operating temperatures, use this DCR at Temperature calculator.
3 Ambient temperature range: −40°C to +85°C
4 Storage temperature range: Component: −40°C to +85°C
Packaging trays: −40°C to +80°C
5 Electrical specifications at 25°C.
Refer to Soldering Coilcraft Components before soldering.

Your comments and suggestions are welcome. Contact [email protected]
Copyright © 2020, Coilcraft, Inc.   Privacy policy
Updated: April 16, 2018