Document 489 -1

High Power PoE Signal Path Magnetics• Meets the current requirements of Gigabit PoE Plus.
• Open circuit inductance is ≥350 µH with a 22.5 mA dc offset

Core material Ferrite
Terminations RoHS Tin-silver-copper over tin over nickel over phosbronze. Other terminations available at additional cost.
Weight HPF2187L: 240 mg; HPX2126L: 3.9 g
Ambient temperature –40°C to +85°C
Storage temperature Component: –40°C to +85°C.
Tape and reel packaging: –40°C to +80°C
Resistance 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)
Packaging
HPF2187L: 500/7″ reel; 2000/13″ reel; Plastic tape: 16 mm wide,0.35 mm thick, 8 mm pocket spacing, 4.4 mm pocket depth
HPX2126L: 300/13″ reel; Plastic tape: 32 mm wide, 0.5 mm thick,
20 mm pocket spacing, 11 mm pocket depth
PCB washing Tested to MIL-STD-202 Method 215 plus an additionalaqueous wash. See Doc787_PCB_Washing.pdf.

Isolation TransformerPartnumber1
HPX2126L_

Common Mode Choke

Inductance2 DCR max3(µH)(Ohms)
850

Isolation4(Vrms)

Irms5(A)Part
number1

Inductance2(µH)

DCR max3(Ohms)

1500

1.9

HPF2187L_

10.0

0.15

0.24

1. When ordering, please specify packaging code:

1. When ordering, please specify packaging code:

HPX2126LD
D = 13″ machine-ready reel. EIA-481 embossed plastic
tape (300 parts per full reel). Quantities less thanfull reel available: in tape (not machine ready) orwith 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.
2. Inductance measured at 100 kHz, 0.1 Vrms, 0 Adc.
3. DCR is for each winding.
4. Isolation is measured from primary to secondary of each transformer.
5. Current flowing through each secondary that causes a 20°C temperature rise from 25°C ambient
6. Electrical specifications at 25°C.
Refer to Doc 362 “Soldering Surface Mount Components” before soldering.

HPF2187LC
C = 7″ machine-ready reel. EIA-481 embossed plastic
tape (500 parts per full reel). Quantities less thanfull reel available: in tape (not machine ready) orwith leader and trailer ($25 charge).
D = 13″ machine-ready reel. EIA-481 embossed plastic
tape. Factory order only, not stocked (2000 parts perfull reel).
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 C.
2. Inductance measured at 100 kHz, 0.1 Vrms, 0 Adc.
3. DCR is for each winding.
4. Electrical specifications at 25°C.
Refer to Doc 362 “Soldering Surface Mount Components” before soldering.

Packaging:

Packaging: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 489-1

Revised 12/22/21© 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 489-2

High Power PoE Signal Path Magnetics
Isolation transformer
HPX2126L

112Chipset side

TXCT
RXCTRX+

211C38 pF

3104

958

7

2

TX–
TXCT
RXCT

63RX+

C68 pF

C533 pF

C48 pF
6RX–

TX+

C233 pF

C1
Note 1TX–

84

7Cable side

1TX+

Common mode choke
HPF2187L

5RX–

Note 1. C1 = 8 pF minus the output capacitance of the chipset

Isolation Transformer HPX2126L
6Dot indicates pin 1

16Common Mode Choke HPF2187L
Notch indicates pin 1

0.050
1,271

1HPF
2187L

0.217 ±0.006
5,50 ±0,1548HPF2187L
XX

5Current production part marking

Recommended
Land Pattern

0.720 max
18,290.560
14,22Previous production part marking

0.307 ±0.008
7,80 ±0,200.138 ±0.008
3,50 ±0,20

7

7

12

120.110
cen2,76

0.620
max
15.75

0.236 *
6,00

0.080
2,030.0395*
1,00
50.0240,604

10.425 max
10,800.007 / 0,180.317 ±0.012
8,05 ±0,30

80.050cen
1,27* Dimensions are typical prior to applying solder

0.050 cen
1,270.030
0,76

10.012
0,305

0.098
2,50

Recommended
Land Pattern

4inches
Dimensions are inmm

850.200
5,08

Dimensions are in

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

0.060
1,52inches
mmDocument 489-2

Revised 12/22/21© 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 489-3

High Power PoE Signal Path Magnetics
Description

Coilcraft’s signal path magnetics meet the current requirements of Gigabit Ethernet PoE Plus. The open circuit
inductance is ≥350 µH with a 38 mA dc offset applied
from 0°C to 70°C. It can handle 3.8 A of injected current.
The system comprises an isolation transformer, a common mode choke and six capacitors. The capacitor
across the primary of the isolation transformer on the TX
side tunes the circuit by matching the output capacitanceof the chipset allowing these components to be used with
virtually all chipsets.
The two isolation transformers are placed in a single
package (HPX2126L) and both common mode chokes
in an even smaller package (HPF2187L). Both packages
fit easily behind a standard Ethernet jack.

Testing

A matching network is used to perform the testing for
return loss, insertion loss, crosstalk, common mode tocommon mode rejection and differential to common mode
rejection. The network matches the 50 Ohm single ended
connection of network analyzers to 100 Ohm differentialbalanced lines. A 1:1 balun is used with a resistive network to transform the impedance. The network is thencalibrated out of the measurement by using open, short,For return loss, the chip side of the component is loadedwith 100 Ohms and the cable side of the system is tested
using the matching network.
For insertion loss, the fixture used for the return loss isaltered to replace the 100 Ohm load with a matching
network for the output port of the network analyzer.
For common mode to common mode rejection, TX+ andTX– (or RX+ and RX–), depending on the side of thesystem) is tied together and an S21 measurement istaken from chip side to cable side.
For differential to common mode rejection, the chip side of
the system is excited by the network analyzer through thematching network. The measurement is taken by looking
at the balance between two 50 Ohm loads across thecable side of the system.
For crosstalk, the chip side TX is excited by the network
analyzer through the matching network. The center-tap
on the chip side of each isolation transformer is grounded,and the chip side RX is measured. The cable side of both
RX and TX is externally loaded 100 Ohms.

Insertion Loss

0010102020Insertion Loss (dB)

Return Loss (dB)

Return Lossload calibration techniques. The circuit is then placed
behind the matching network for each of the tests. Alltests are performed on an Agilent/HP 8753ES network
analyzer.

3040506070803040506070809090100100

110100Frequency (MHz)802.3af specification:
18 dB min from 1 MHz to 40 MHz
16 dB min at 50 MHz
12 dB min at 80 MHz
10 dB min at 100 MHz

1000

1101001000

Document 489-3

Revised 12/22/21

Frequency (MHz)802.3af specification:
1.0 min dB from 0.1 MHz to 100 MHz
1.2 min dB at 125 MHz

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© 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 489-4

High Power PoE Signal Path Magnetics
Differential to Common Mode Rejection

0Common Mode Rejection (dB)

102030405060
708090100

110100Frequency (MHz)1000

Differential to Common Mode Rejection (dB)Common Mode Rejection

0102030405060708090100

1101001000

Frequency (MHz)802.3af specification:
50 dB min from 1 MHz to 10 MHz30 dB min from 10 MHz to 125 MHz
20 dB min from 125 MHz to 500 MHz

802.3af specification:
45 dB min at 30 MHz
40 dB min at 60 MHz
35 dB min at 100 MHz

Crosstalk

L vs Offset Current – HPX2126L
1400

0101200
1000

30Inductance (µH)

Crosstalk (dB)

2040
50
60
70

800
600
400
85°C

80
90
100

70°C

25°C

200
01

10100

Frequency (MHz)

1000

010

20

30

405060Current (mA)

802.3af specification:
45 dB min at 30 MHz
40 dB min at 60 MHz
33 dB min at 100 MHz

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 489-4

Revised 12/22/21© 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.