Document 458

Flyback Transformers

For National Semiconductor
LM5070 PoE Interface – 7 Watt

• Flyback transformers for 7 W PoE applications• Designed to operate in continuous mode at 250 kHz with an
input of 36 – 72 Vdc• 1500 Vrms isolation from primary and bias to secondaryCore material Ferrite
Terminations RoHS tin-silver over tin over nickel over phos bronze.
Other terminations available at additional cost.
Weight 3.85 g
Ambient temperature –40°C to +85°C
Storage temperature Component: –40°C to +85°C.
Tape and reel packaging: –40°C to +80°CResistance to soldering heat Max three 40 second reflows at+260°C, parts cooled to room temperature between cycles
Moisture Sensitivity Level (MSL) 1 (unlimited floor life at <30°C /85% relative humidity)
PCB washing Tested to MIL-STD-202 Method 215 plus an additionalaqueous wash. See Doc787_PCB_Washing.pdf.		
InductancePartat 0 A2
number1 ±10% (µH)
C1587-AL_155
C1588-AL_155
C1589-AL_155

Inductanceat Ipk3min (µH)
139.5
139.5
139.5			Leakage		
DCR max (Ohms)4
inductance    Turns ratio6
pribiassecmax (µH)5pri : sec pri : bias
0.414 0.822 0.036
4.00
1 : 0.19
1 : 0.667
0.414 0.822 0.060
3.60
1 : 0.262
1 : 0.667
0.414 0.822 0.343
3.25
1 : 0.667
1 : 0.667

1. When ordering, please specify packaging code:
Packaging:

C1589-ALD
D = 13″ machine-ready reel. EIA-481 embossed plastictape. Quantities less than full reel available: in tape (notmachine ready) or with leader and trailer ($25 charge).
B = Less than full reel. In an effort to simplify our partnumbering system, Coilcraft is eliminating the needfor multiple packaging codes. When ordering, simply
change the last letter of your part number from B to D.

Ipk3(A)
Output70.65 3.3 V, 2.12 A
0.65 5.0 V, 1.4 A
0.65 12 V, 0.6 A

2. Inductance is for the primary, measured at 10 kHz, 0.1 Vrms, 0 Adc.
3. Ipk is peak primary current drawn at minimum input voltage.
4. DCR for the secondary is per winding.
5. Leakage inductance measured between pins 3 and 4 with all other pins
shorted.
6. Turns ratio is with the secondary windings connected in parallel.
7. Output of the secondary is with the windings connected in parallel. Bias
winding output is 12 V, 20 mA.
8. Electrical specifications at 25°C.
Refer to Doc 362 “Soldering Surface Mount Components” before soldering.

Dot above pin1

0.433
max
11,00

Pri

10.0240,60
8Recommended
Land Pattern
0.080
2,030.460
11,68

Bias
0.050
1,27

0.50
max
12,7
4

1

50.0982,50

78

20.600
max
15,24
0.413
10,50

Sec

40.004 /0,100.041
1,05

653

Dimensions are ininchesmm0.098
2,50

1Secondary windings to be connectedin parallel on the PC board

Packaging:
C1587-AL 250 per 13″ reel Plastic tape: 32 mm wide,0.5 mm thick, 20 mm pocket spacing, 11.2 mm pocket depth
C1588 / C1589-AL 200 per 13″ reel Plastic tape: 32 mm wide,
0.5 mm thick, 24 mm pocket spacing, 11.2 mm pocket depth

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 458

Revised 07/28/21© 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.