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Cx Family Common Mode Chokes
0402CT Low Profile Chip Inductors
XAL7050 High-inductance Shielded Power Inductors
XGL4020 Ultra-low DCR Power Inductors

GA3429-BL Flyback Transformer

for Linear Technology LT3573

RoHS compliant
  • Developed for Linear Technology LT3573 Isolated Flyback Converter
  • Can also be used in PoE applications
  • Bias winding provides power to the chipset

Buy Now:
Count Unit price
1 $3.42
250 $2.92
500 $2.55
1000 $2.00
2500 $1.71
5000 $1.56

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

. in stock, ready to ship today.
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Typical Application

Works with Analog Devices LT3573

Input Voltage Output 1 Power Fsw
Sec Bias
20 V 28 V 3.3 V , 1.5 A 3.3 V , 0.02 A 5 W 250 kHz


Electrical specifications at 25°C.

Part number 2
(Hover for schematics)
at 0A (µH) 3
(Tolerance: ±10%)
min at   2.1 A (µH)
DCR max (mΩ) 4 Leakage
max (µH) 5
Turns Ratio 6 Isolation
Voltage (Vrms) 7
Pri Sec Bias Pri : Sec : Bias
GA3429-BL_ 24.0 21.6 95.0 7.5 123 0.566 1 : 0.25 : 0.25 1500
  1. Output is with the secondary windings connected in parallel. Bias winding output: 3.3 V, 20 mA.
  2. When ordering, please specify packaging code: GA3429-BLD.
  3. Inductance is for the primary, measured at 250 kHz, 0.3 Vrms, 0 Adc.
  4. DCR for the secondary is per winding.
  5. Leakage inductance measured between pins 3 and 4 with all secondary pins shorted.
  6. Turns ratio is with the secondary windings connected in parallel.
  7. 1500 Vrms isolation from primary and bias to secondary;
    500 Vrms isolation from primary to bias, tested for one minute.


  • 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.


  • D = 13″ machine-ready reel. EIA-481 embossed plastic tape (250 parts per full reel). Quantities less than full reel available: in tape (not machine ready) or with leader and trailer ($25 charge).
  • B = Less than full reel. In an effort to simplify our part numbering system, Coilcraft is eliminating the need for multiple packaging codes. When ordering, simply change the last letter of your part number from B to D.
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_f-(1).gif
250 330 100 13 38,4 32,4 32 20 4 2 11,2 0,5

General specification

Core Material:
3.9 to 4.1 g
250 per 13″ reel Plastic tape: 32 mm wide, 0.5 mm thick, 20 mm pocket spacing, 11.2 mm pocket depth.


Moisture Sensitivity Level (MSL):
1 (unlimited floor life at <30°C / 85% relative humidity)
Resistance to soldering heat:
Max three 40 second reflows at +260°C, parts cooled to room temperature between cycles
Refer to Soldering Coilcraft Components before soldering.
PCB Washing:
Tested with pure water or alcohol only. For other solvents, see Doc787_PCB_Washing.pdf

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