Document 746-1

Magnetics for 300 W Power Supply with PFC• Specified by Texas Instruments in Reference Design SLUU341
for 300 Watt Isolated PFC Power Supply• HA3950-AL, Flyback transformer (T201) for 5 W bias supply
operates with an input voltage range of 100 – 450 V.
• HA3858-AL, Gate drive transformer (T301)

Core material Ferrite
Terminations RoHS compliant tin-silver over tin over copper. Other
terminations available at additional cost.
Weight HA3950-AL: 13.5 g; HA3858-AL: 4.1 g
Ambient temperature –40°C to +85°C
Storage temperature Component: –40°C to +85°C.
Tray packaging: –40°C to +80°C
Moisture Sensitivity Level (MSL) 1 (unlimited floor life at <30°C /85% relative humidity)
Packaging 100 per tray
PCB washing Tested with pure water or alcohol only. For other solvents,
see Doc787_PCB_Washing.pdf.

HA3950-AL Flyback Transformer		PartnumberInductanceat 0 A1±10% (mH)

Inductance		
Leakage
at Ipk2
DCR maxinductance(mH)(Ohms)	 max (µH)3

HA3950-AL
2.3
1.61								0.860 (pri)0.109 (sec)
0.080 (P1)

16.5

Turns ratio
Pri:Sec:P1Ipk2(A)Output4

1 : 0.16 : 0.11

0.3

15 V, 0.33 A

Dot indicates pin 1

1. Inductance measured at 100 kHz, 0.1 Vrms, 0 Adc using an Agilent/
HP 4263B impedance analyzer or equivalent.
2. Peak primary current drawn at minimum input voltage.
3. Leakage inductance is for the primary and is measured with the secondary shorted.
4. Output of the P1 winding is 10 V, 20 mA.
5. Isolation: 3000 Vrms, one minute primary to secondary;
500 Vrms, one minute windings to core
6. Electrical specifications at 25°C.

0.680 max
17,300.110
min
2,790.197
5,00.590
15,00.830
21,118PriSec

254

150.590
15,080.197
5,00.830 max
21,1

3P10.025
0,64

1

4
Dimensions are in8inchesmm

US +1-847-639-6400 sales@coilcraft.com
UK +44-1236-730595 sales@coilcraft-europe.com
Taiwan +886-2-2264 3646 sales@coilcraft.com.tw
China +86-21-6218 8074 sales@coilcraft.com.cn
Singapore + 65-6484 8412 sales@coilcraft.com.sg

40.048
1,25Recommended
PC Board Layout

Document 746-1

Revised 11/23/21© Coilcraft Inc. 2021
This product may not be used in medical or highrisk applications without prior Coilcraft approval.
Specification subject to change without notice.
Please check web site for latest information.

Document 746-2

Magnetics for 300 W PFC Power Supply
HA3858-AL Gate Drive Transformer			PartTurns
numberratio

Primary
inductance1±25% (µH)

Leakage		
inductance2
DCR maxmax (µH)(Ohms)

Volt-time
product(V-µsec)SRF
typ3(MHz)

HA3858-AL
1:1:1
460
1.87 (1 – 2)
0.380 (Pri [A])150
1.15				2.06 (3 – 4)
0.472 ((Pri [B])								0.424 (sec)

Capacitancemax (pF)
8.48 (pri)28.66 (sec)

1. Inductance is for each winding, measured at 200 kHz, 0.4 Vrms, 0 Adc.
2. Leakage inductance is for each primary, measured at 200 kHz, 0.4 Vrms with secondary pins shorted.
3. SRF measured with coils connected in series using an Agilent/HP 4192 or equivalent.
4. Operating temperature range −40°C to +85°C.
5. Isolation: 3000 Vrms, one minute primary to secondary; 500 Vrms, one minute windings to core
6. Electrical specifications at 25°C.
Dot indicates pin 10.350
max
8,89

18

Pri [ A]Sec

2

730.541
13,75

0.125
min
3,180.148
3,75

Pri [ B]
40.675max
17,150.148
3,751540.024∅
0,60.541
13,75

80.650
max
16,51
8

1

Dimensions are ininches
mm0.030 ∅0,762

45

Recommended
PC Board Layout

US +1-847-639-6400 sales@coilcraft.com
UK +44-1236-730595 sales@coilcraft-europe.com
Taiwan +886-2-2264 3646 sales@coilcraft.com.tw
China +86-21-6218 8074 sales@coilcraft.com.cn
Singapore + 65-6484 8412 sales@coilcraft.com.sg

Document 746-2

Revised 11/23/21© Coilcraft Inc. 2021
This product may not be used in medical or highrisk applications without prior Coilcraft approval.
Specification subject to change without notice.
Please check web site for latest information.