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Cx Family Common Mode Chokes
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XAL7050 High-inductance Shielded Power Inductors
XGL4020 Ultra-low DCR Power Inductors

HA3905 Flyback Transformer

for Microsemi PoE PD Power supply

RoHS compliant
  • Developed for use with Microsemi UC3844 Current Mode Controller and LX1752 Buck Regulator
  • T1 on PoE PD Power Supply Evaluation Board (AN-37)
Buy Now:
Count Unit price
1 $2.07
175 $1.98
700 $1.65
1400 $1.37
2800 $1.20
5000 $1.04

For high volume or non-stock items, request a quote.

. in stock, ready to ship today.
Request a Sample:

Typical Application

Works with Microsemi UC3844

Input Voltage Output 1 Power Fsw
Sec Aux
36 V 57 V 5 V , 2.5 A 12 V , 0.02 A 12.5 W 200 kHz


Electrical specifications at 25°C.

Part number 2
(Hover for schematics)
at 0A (µH) 3
(Tolerance: ±10%)
min at   1.2 A (µH)
DCR max (Ω) Leakage
max (µH) 4
Turns Ratio Isolation
Voltage (Vrms) 5
Pri Sec Aux Reset Pri : Sec : Aux : Reset
HA3905-CL_ 27.0 24.3 0.170 0.015 0.385 0.371 1.9 1 : 0.267 : 0.735 : 1 1500
  1. Output of the seconday is with the windings connected in parallel.
  2. When ordering, please specify packaging code: HA3905-CLD.
  3. Inductance is for the primary, measured at 250 kHz, 0.1 Vrms, 0 Adc.
  4. Leakage inductance measured on the primary winding with all secondary pins shorted.
  5. 1500 Vrms,one minute isolation from primary, auxiliary and reset to secondary;
    500 Vrms, one minute isolation from primary and reset to auxiliary


  • RoHS-compliant. 260°C compatible. Tin-silver (96.5/3.5) over tin over nickel over phos bronze terminations. Other terminations available at additional cost.


  • 13" reel, machine-ready 
    EIA-481 embossed plastic tape (175parts 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.
RoHS compliant
Ambient temperature range:
-40°C to +85°C
Storage temperature range:
Component: –40°C to +85°C.
Tape and reel packaging: –40°C to +80°C
Failures in Time (FIT) / Mean Time Between Failures (MTBF):



Secondary windings to be connected
in parallel on the PC board

Physical characteristics



Tape and Reel specification

Parts per reel Reel dimensions (mm) Tape dimensions (mm) Orientation
13" (330 mm) A B C D E W P Po P1 H T part_or_c-(9).gif
175 330 100 13 38,4 32,4 32 28 4 2 12,93 0,5

General specification

Core Material:
6.7 g
175 per 13″ reel Plastic tape: 32 mm wide, 0.5 mm thick, 28 mm pocket spacing, 12.93 mm pocket depth


Moisture Sensitivity Level (MSL):
1 (unlimited floor life at <30°C / 85% relative humidity)
Resistance to soldering heat:
t Max three 40 second reflows at +260°C, parts cooled to room temperature between cycles
Refer to Soldering Coilcraft Components before soldering.
PCB Washing:
Only pure water or alcohol recommended

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