1
dc2539aafb
DEMO MANUAL
DC2539A-A
Description
LT4295, LT4321
High Efficiency IEEE802.3bt (PoE++, Type 3, 51W) PD
with Flyback DC/DC Converter and Auxiliary Power Input
Demonstration circuit 2539A is an IEEE802.3bt (Draft 2.1)
compliant Power over Ethernet (PoE) Powered Device
(PD). It features the LT
®
4295 PD interface and switch-
ing regulator controller and the LT4321 PoE ideal diode
bridge controller.
The LT4295 provides IEEE802.3af (PoE, Type 1),
IEEE802.3at (PoE+, Type 2), and IEEE802.3bt (PoE++,
Type 3) compliant interfacing and power supply control. It
utilizes an external, low RDS(ON) (57mΩ typical) N-channel
FET for the hot swap function to improve efficiency. The
LT4295 controls a DC/DC converter that utilizes a highly
efficient Flyback topology with synchronous rectification.
The LT4321 controls eight low RDS(ON) (30mΩ typical)
N-channel FETs to further improve end-to-end power
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Analog
Devices, Inc. All other trademarks are the property of their respective owners.
performance summary
BoarD photos
delivery efficiency and ease thermal design. This solution
replaces the eight diodes typically found in a passive PoE
rectifier bridge.
The DC2539A-A accepts up to 51W of delivered power
from a Power Sourcing Equipment (PSE) via the RJ45
connector (J1) or a local 48VDC power supply using the
auxiliary supply input. When both supplies are connected,
the auxiliary supply input has priority over the PoE input.
The DC2539A-A supplies a 12V output at up to 3.9A.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2539A-A
Specifications are at TA = 25°C
Top Side Bottom Side
PARAMETER CONDITIONS VALUE
Port Voltage (VPORT) At RJ45 37V to 57V
Auxiliary Voltage From AUX+ to AUX– Terminals 37V to 57V
Output Voltage (VOUT) 12V (Typical)
Output Current (IOUT) 3.9A (Max)
Output Voltage Ripple VPORT = 42.5V, IOUT = 3.9A 54mVP-P (Typical)
Load Regulation ±0.4% (Typical)
Efficiency VPORT = 50V, IOUT = 3A, End-to-End 91.5% (Typical)
Switching Frequency 250kHz (Typical)
2
dc2539aafb
DEMO MANUAL
DC2539A-A
typical performance characteristics
Top Side Bottom Side
Figure 2. Efficiency (End-to-End)
Figure 1. Thermal Pictures (Conditions: VPORT = 57V, VOUT = 12V, IOUT = 3.9A)
3
dc2539aafb
DEMO MANUAL
DC2539A-A
typical performance characteristics
Figure 3. Load Regulation
4
dc2539aafb
DEMO MANUAL
DC2539A-A
typical performance characteristics
Figure 5. Output Voltage Ripple (Conditions: VPORT = 42.5V, VOUT = 12V, IOUT = 3.9A)
Figure 4. Switch Node Waveforms (Conditions: VPORT = 57V, VOUT = 12V, IOUT = 3.9A)
5
dc2539aafb
DEMO MANUAL
DC2539A-A
typical performance characteristics
Figure 6. Load Transient Response (Conditions: VPORT = 42.5V, Load Step: 2A to 4A to 2A)
6
dc2539aafb
DEMO MANUAL
DC2539A-A
typical performance characteristics
Figure 7. Gain and Phase Margin of the Flyback DC/DC Converter (Conditions: VPORT = 57V, VOUT = 12V, IOUT = 3.9A)
CROSSOVER FREQUENCY GAIN MARGIN PHASE MARGIN
≈5.8kHz ≈20dB ≈63°
7
dc2539aafb
DEMO MANUAL
DC2539A-A
Quick start proceDure
Power Over Ethernet (PoE) Input
1 Disconnect auxiliary supply if it is connected to AUX+
and AUX– inputs of the DC2539A-A.
2 Place and connect test equipment (voltmeter, ammeter,
oscilloscope, and electronic load) as shown in Figure 8.
3 Turn down the electronic load to a minimum value and
turn off the electronic load.
4 Connect the output of the IEEE 802.3bt compliant PSE
to the RJ45 connector (J1) of the DC2539A using a
CAT5e or CAT6 Ethernet cable. (See note.)
5 After the LED (D4) on the DC2539A is lit, check the
output voltage using a voltmeter. Output voltage should
be within 12.0V±0.2V.
6 Turn on the electronic load and increase its load cur-
rent up to 3.9A. Observe the output voltage regulation,
efficiency, and other parameters.
7 Verify T2P response with an oscilloscope as shown
in Figure 8. The T2P response to the type of PSE con-
nected to the DC2539A-A is provided in Table 1.
Note: An 802.3bt PSE has not yet been released. In
the interim, an LTPoE++
®
compliant PSE (DC1814A-B)
may be used to provide power to the DC2539A-A. The
LTPoE++ classification will not be 802.3bt compliant, but
the PSE will provide a compatible detection and power
output. Specifically, the T2P output of the DC2539A-A
is different from the behavior stated in Table 1 and will
indicate connection to a Type 2 PSE. Otherwise PD
behavior will be unaffected.
Figure 8. Setup Diagram for PoE Input
IEEE802.3bt
PSE
CAT5e
OR CAT6
CABLE
+
–
DC POWER
SUPPLY
+
–
VOLT
METER
+
–AM
METER
+
–
ELECTRONIC
LOAD
+
–
OSCILLOSCOPE
DC2539 F08
+
–
Table 1. T2P Response
PSE T2P Response Negotiated PD Input Power
IEEE
Logic High 13W
Logic Low 25.5W
50% Logic High/50% Logic Low, Toggle at 976Hz ±7% 51W
LTPoE++, 52.7W Logic Low 51W
8
dc2539aafb
DEMO MANUAL
DC2539A-A
Auxiliary Supply Input
1. Place and connect test equipment (voltmeter, ammeter,
oscilloscope, and electronic load) as shown in Figure 9.
2. Turn down the electronic load to a minimum value and
turn off the electronic load.
3. Connect the output of the auxiliary supply to the
DC2539A as shown in Figure 9. Turn on the auxiliary
supply and set its current limit to 2A. Then increase its
output voltage to 48V.
Quick start proceDure
4. Once the LED (D4) on the DC2539A is lit, check the
output voltage using a voltmeter. Output voltage should
be within 12.0V±0.2V.
5. Turn on the electronic load and increase its load cur-
rent up to 3.9A. Observe the output voltage regulation,
efficiency, and other parameters.
6. Verify T2P response with an oscilloscope as shown
in Figure 9. The T2P response during auxiliary power
operation is: 75% Logic High/25% Logic Low, Toggle
at 976Hz ±7%
VOLT
METER
+
–AM
METER
+
–
ELECTRONIC
LOAD
+
–
OSCILLOSCOPE
DC2539 F09
+
–
AUXILIARY
SUPPLY
+–
Figure 9. Setup Diagram for Auxiliary Supply Input
9
dc2539aafb
DEMO MANUAL
DC2539A-A
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
DC2539A General BOM
1 1 CG1 CAP, CER, X7R 1000pF 2kV 10% 1808 MURATA GR442QR73D102KW01L
2 1 CG2 CAP, CER, X7R 0.01µF 100V 20% 1206 AVX 12061C103MAT2A
3 0 C1 CAP, CER, OPT 2kV 1812 OPT
4 0 C5 CAP, CER, X7U OPT 6.3V 10% 1210 OPT
5 1 C6 CAP, ELEC, 10µF 100V 20% 6.3 × 7.7 SUNCON 100CE10KX
6 1 C7, C29 CAP, CER, X7R 2.2µF 100V 10% 1210 MURATA GRM32ER72A225KA35
7 1 C10 CAP, CER, X7R 10nF 100V 20% 0603 MURATA GRM188R72A103KA01D
8 2 C11, C12 CAP, CER, X7R 0.047µF 100V 10% 0603 KEMET C0603C473K1RACTU
9 1 C13 CAP, CER, X7R 10µF 10V 10% 1206 MURATA GRM31CR71A106KA01L
10 0 C15, C18, C19, C21 CAP, CER, X5R OPT 2kV 20% 1812 OPT
11 1 C17 CAP, CER, X7R 1µF 25V 10% 0603 MURATA GRM188R71E105KA12
12 1 C20 CAP, CER, X7R 2.2nF 25V 10% 0603 MURATA GRM188R71E222KA01
13 1 C23 CAP, CER, X7R 4.7nF 2kV 1812 MURATA GR443DR73D472KW01L
14 1 C26 CAP, CER, X7R 100pF 16V 0402 AVX, 0402YC101KAT2A
15 0 C27 CAP, CER, X7R OPT 6.3V 10% 0402 OPT
16 1 D1 DIODE, SCHOTTKY, PMEG10020 100V SOD128 NXP PMEG10020AELPX
17 3 D2, D16, D19 DIODE, TVS, PTVS58VS1UR 58V SOD123 NXP PTVS58VS1UR
18 1 D3 DIODE, ZENER, MMSZ5252BS 24V SOD323 DIODES INC MMSZ5252BS
19 1 D4 DIODE, LED GREEN ROHM SML-010FTT86L
20 1 D13 DIODE, SCHOTTKY, NXP, BAT46W 100V SOD323 NXP BAT46WJ,115
21 1 D15 DIODE, DIODE INC, BAV19WS 120V SOD323 DIODE INC BAV19WS
22 1 D17 DIODE, SCHOTTKY, PMEG1020EA 10V SOD323 NXP PMEG1020EA
23 8 E2, E3, E4, E5, E6, E9,
E11, E12
TP, TURRET, PAD150-094 0.094" MILL-MAX 2501-2-00-80-00-00-07-0
24 1 J1 CONN, INTEGRATED JACK, 7499511001A WURTH 7499511001A
25 1 J2 CONN, RJ45 JACK, SS-6488-NF-K1 STEWART CONNECTOR SS-6488-NF-K1
26 2 J3, J4 CONN, BANANA, 575-4 0.175" KEYSTONE 575-4
27 1 L2 IND, 4.7µH WURTH 744316470
28 1 L4 IND, 100µH COILCRAFT DO1608C-104
29 0 L5 IND, OPT OPT
30 9 Q11, Q12, Q13, Q14,
Q15, Q16, Q17, Q18
MOSFET, N-CH, PSMN075-100MSE 100 LFPAK33 NXP PSMN075-100MSE
31 1 Q1 MOSFET, N-CH, PSMN040-100MSE 100 LFPAK33 NXP PSMN040-100MSE
32 1 Q5 TRANSISTOR, PNP, PBSS5140T 40V SOT23 NXP PBSS5140T
33 1 Q6 TRANSISTOR, NPN, PBSS4140T 40V SOT23 NXP PBSS4140T
34 1 Q7 TRANSISTOR, PNP, FMMT723 100V SOT23 DIODES INC FMMT723TA
35 4 RT1, RT2, RT3, RT4 RES, CHIP, 75Ω 5% 0603 NIC NRC06J750TRF
36 1 R5 RES, CHIP, 8.2Ω 5% 0805 NIC NRC10J8R2TRF
37 1 R6 RES, CHIP, 3.3k 5% 0603 NIC NRC06J332TRF
38 1 R7 RES, CHIP, 20Ω 5% 0805 VISHAY CRCW080520R0JNEA
39 1 R12 RES, CHIP, 0Ω 5% 0603 NIC NRC06ZOTRF
parts list
10
dc2539aafb
DEMO MANUAL
DC2539A-A
parts list
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
40 1 R13 RES, CHIP, 100Ω 5% 0603 VISHAY CRCW0603100RFKEA
41 1 R15 RES, CHIP, 15Ω 5% 0603 NIC NRC06J150TRF
42 1 R17 RES, CHIP, 2.00k 1% 0603 NIC NRC06F2001TRF
43 1 R18, RES, CHIP, 10k 5% 0603 YAGEO RC0603JR-0710KL
44 1 R21 RES, CHIP, 174k 1% 0603 VISHAY CRCW0603174KFKEA
45 1 R22 RES, CHIP, 107k 1% 0603 NIC NRC06F1073TRF
46 2 R27, R31 RES, CHIP, 0Ω SHUNT 0402 NIC NRC04ZOTRF
47 1 R28 RES, CHIP, 0Ω SHUNT 0603 NIC NRC06ZOTRF
48 1 R29 RES, CHIP, 52.3k 1% 0603 VISHAY CRCW060352K3FKEA
49 0 R32 RES, CHIP, OPT 5% 1812 OPT
50 0 R33 RES, CHIP, OPT 5% 0805 OPT
51 1 T3 XFMR, SMD GATE DRIVE, EPA4271GE PCA EPA4271GE
52 0 T3 (ALTERNATE) XFMR, SMD GATE DRIVE, PE-68386NL PULSE PE-68386NL
53 1 U3 IC, POE IDEAL BRIDGE CONTROLLER LT4321IUF
QFN16
LINEAR TECH LT4321IUF
54 2 STENCIL (TOP & BOTTOM) STENCIL DC2539A
DC2539A-A
1 1 C2 CAP, CER, X5R 10µF 16V 10% 1210 MURATA GRM32DR61C106KA01
2 1 C3 CAP, CER, X5R 10µF 16V 10% 1210 MURATA GRM32DR61C106KA01
3 1 C4 CAP, ELEC, 47µF 35V 20% 6.0X5.8 PANASONIC EEH-ZA1V470P
4 1 C8 CAP, CER, U2J 330pF 630V 5% 1206 MURATA GRM31A7U2J331JW31
5 1 C9 CAP, CER, U2J 220pF 630V 5% 1206 MURATA GRM31A7U2J221JW31
6 1 C16 CAP, CER, X7R 1µF 25V 10% 0805 MURATA GRM21BR71E105KA99L
7 1 C22 CAP, CER, X7R 3.3nF 25V 10% 0603 AVX 06033C332KAT2A
8 1 C24 CAP, CER, X7R 0.1µF 25V 20% 0603 MURATA GRM188R71E104KA01D
9 1 C25 CAP, CER, X7R 330pF 25V 10% 0603 AVX 06033C331KAT2A
10 0 D18 DIODE, OPT 40V SOD323 OPT
11 1 L1 IND, 220nH WURTH 744316022
12 1 L3 IND, CMC, 6mH, COILCRAFT UA8085-AL
13 1 Q2 MOSFET, N-CH, 150V SOP ADVANCE TOSHIBA TPH1500CNH
14 1 Q4 MOSFET, N-CH, 150V SOP ADVANCE TOSHIBA TPH1500CNH
15 1 R2 RES, CHIP, 1.5k 5% 0805 NIC NRC10J152TRF
16 1 R3 RES, CHIP, 75Ω 5% 1206 VISHAY CRCW120675R0JNEA
17 1 R4 RES, CHIP, 75Ω 5% 1206 VISHAY CRCW120675R0JNEA
18 1 R8 RES, CHIP, 39Ω 5% 1206 VISHAY CRCW120639R0JNEA
19 1 R9 RES, CHIP, 39Ω 5% 1206 VISHAY CRCW120639R0JNEA
20 1 R10 RES, CHIP, 5.62k 1% 0603 VISHAY CRCW06035K62FKEA
21 1 R11 RES, CHIP, 5.23k 1% 0603 YAGEO RC0603FR-075K23L
11
dc2539aafb
DEMO MANUAL
DC2539A-A
parts list
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
22 1 R14 RES, CHIP, 20mΩ 1% 2010 VISHAY WSL2010R0200FEA
23 1 R16 RES, CHIP, 0Ω, Shunt, 0805 VISHAY CRCW08050000Z0EA
24 1 R19 RES, CHIP, 47.5Ω 1% 0805 VISHAY CRCW080547R5FKEA
25 1 R20 RES, CHIP, 150Ω 1% 0805 VISHAY CRCW0805150RFKEA
26 0 R23 RES, CHIP, OPT 5% 0603 OPT
27 1 R24 RES, CHIP, 30k 5% 0603 VISHAY CRCW060330K1JNEA
28 1 R25 RES, CHIP, 10k 5% 0603 YAGEO RC0603JR-0710KL
29 1 R26 RES, CHIP, 4.7k 5% 0603 NIC NRC06J472TRF
30 0 R30 RES, CHIP, OPT 5% 0805 OPT
31 1 T1 XFMR, FLYBACK TRANSFORMER, EPC3633G PCA EPC3633G
32 0 T1 (ALTERNATE) XFMR, FLYBACK TRANSFORMER, 750316116 WURTH 750316116
33 1 U1 IC, PD & SWITCHER CONTROLLER, LT4295IUF
QFN28
LINEAR TECH LT4295IUF
34 1 ISO1 IC, TRANSISTOR OUTPUT OPTOCOUPLER, SO4 TOSHIBA TLP291(GR-TP,SE)
35 4 MH1-MH4 STAND-OFF, NYLON 0.50" TALL (SNAP ON) KEYSTONE 8833
36 1 FAB, PRINTED CIRCUIT BOARD DEMO CIRCUIT 2539A
12
dc2539aafb
DEMO MANUAL
DC2539A-A
schematic Diagram
5
5
4
4
3
3
2
2
1
1
D
D
C
C
B
B
A
A
VPORTP
-VOUT
+VOUT
VPORTN
GND
OPTIONAL COMPONENTS
37V-57V
T2P
___
AUX+
AUX -
12V/3.9A
FLYBACK DC-DC CONVERTER AND AUXILIARY POWER INPUT
VPRI_SG
SG
VPRI_SW
PG
VSEC_SW
VSEC_P
VPRI_P
PG
VSEC_SG
FB VSEC_P
VAUX_P
FB
+VOUT
+VOUT
VPORTP VCC
VCC
+VOUT
VPORTP
VPORTN
REVISION HISTORY
DESCRIPTION DATE
APPROVED
ECO REV
KAUNG H.
PRODUCTION1 2 9-20-2016
REVISION HISTORY
DESCRIPTION DATE
APPROVED
ECO REV
KAUNG H.
PRODUCTION1 2 9-20-2016
REVISION HISTORY
DESCRIPTION DATE
APPROVED
ECO REV
KAUNG H.
PRODUCTION1 2 9-20-2016
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. SCALE = NONE
www.linear.com
2
Tuesday, September 20, 2016
12
HIGH EFFICIENCY IEEE 802.3bt (PoE++, Type 3, 51W) PD WITH
K. HTOO
K. HTOO
N/A
LT4295IUFD, LT4321IUF
DEMO CIRCUIT 2539A-A
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. SCALE = NONE
www.linear.com
2
Tuesday, September 20, 2016
12
HIGH EFFICIENCY IEEE 802.3bt (PoE++, Type 3, 51W) PD WITH
K. HTOO
K. HTOO
N/A
LT4295IUFD, LT4321IUF
DEMO CIRCUIT 2539A-A
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. SCALE = NONE
www.linear.com
2
Tuesday, September 20, 2016
12
HIGH EFFICIENCY IEEE 802.3bt (PoE++, Type 3, 51W) PD WITH
K. HTOO
K. HTOO
N/A
LT4295IUFD, LT4321IUF
DEMO CIRCUIT 2539A-A
D13
BAT46WJ,115
12
Q1
PSMN040-100MSE
6
4
5
8
7
1
2
3
4.7uH
L2
WURTH
744316470
R26
4.7K
3.3nF
C22
1uF
C16
0805
R33
OPT
exposed pad, solder side
U1
LT4295IUFD
VPORT 28
HSGATE 26
HSSRC 25
SWVCC 23
DNC
22
VCC 21
VIN 24
PG 20
FB31
14
ISEN- 16
ISEN+ 17
SG 18
AUX
2
RCLASS++
3
RCLASS
4
GND
19
VCC
6
VCC
7
VCC
8
T2P
5
SFST
11
RLDCMP
15
VCC
9
GND
1
ITHB 13
FFSDLY 12
NC
27
ROSC
10
GND_EP
29
PBSS4140T
Q6
1
2 3
R20
150
0805
R18
10K
E11
D16
PTVS58VS1UR
2 1
R23
OPT
Q7
FMMT723
3 2
1
E3
R10
5.62K
OPT
C19
T1
EPC3633G-LF
1
11
86
4
7
12
5
2
3
PBSS5140T
Q5
1
23
R25
10K
Q2
TPH1500CNH
6
4
5
8
7
1
2
3
R22
107K
R16
0
0805
D1
PMEG10020
2 1
R17
2.00K
220pF
C9
1206
R6
3.3K
OPT
C21
R19
47.5
0805
R9
39
1206
L3
6mH
UA8085-BL
4 3
21
220nH
L1
744316022
R3
75
1206
E9
C10
10nF
100V
2.2uF
100V
1210
X7R
C29
Q4
TPH1500CNH
6
4
5
8
7
1
2
3
330pF
C25
R15
15
R30
OPT
0805
R5
8.2
0805
R27
0
R31
0
D18
OPT
21
EPA4271GE
T3
1
3
6
4
C2
X5R
16V
1210
10uF
E4
ISO1
TLP291(GR-TP,E)
12
43
D17
PMEG1020EA
2 1
E2
2.2uF
100V
1210
X7R
C7 R7
20
0805
R14
20m
2010
E12
R4
75
1206
J4
0.047uF
C12
100V
HSS
OPT
L5
4.7nF
C23
330pF
C8
1206
2.2nF
C20
R35
OPT
1uF
C17
+
C4
47uF
35V
EEH-ZA1V470P
R21
174K
R12
0
R11
5.23K
100uH
L4
DO1608C-104
+
10uF
100V
6.3x7.7
C6
D15
BAV19WS
2 1
R24
30K
R29
52.3K
D4
LED
E6
+
C5
OPT
OPT
C1
OPT
C15
OPT
C27
6.3V
D19
PTVS58VS1UR
2 1
10uF
C13
10V
1206
E5 R34
0
OPT
C18
C3
10uF
1210
X5R
16V
J3
R32
OPT
R8
39
1206
100pF
C26
25V
0.1uF
C24
R2
1.5K
R13
100
13
dc2539aafb
DEMO MANUAL
DC2539A-A
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
schematic Diagram
5
5
4
4
3
3
2
2
1
1
D
D
C
C
B
B
A
A
OUT
TO
PHY
IN FROM
PoE+
PSE
PoE IDEAL DIODE BRIDGE
FLYBACK DC-DC CONVERTER AND AUXILIARY POWER INPUT
POE_CT45
POE_CT78
POE_CT12
POE_CT36
BG12
BG36
POE_CT36
TG36
TG45
POE_CT45
POE_CT12 POE_CT78
TG12
BG45
TG45
BG36
TG36
BG12
TG78
BG78
VPORTN
BG78
POE_CT78
TG78
POE_CT45
POE_CT12
POE_CT36
TG12
BG45
VPORTN
VPORTP
VPORTN
VPORTP
REVISION HISTORY
DESCRIPTION DATE
APPROVED
ECO REV
KAUNG H.
PRODUCTION1 2 9-20-2016
REVISION HISTORY
DESCRIPTION DATE
APPROVED
ECO REV
KAUNG H.
PRODUCTION1 2 9-20-2016
REVISION HISTORY
DESCRIPTION DATE
APPROVED
ECO REV
KAUNG H.
PRODUCTION1 2 9-20-2016
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. SCALE = NONE
www.linear.com
2
Tuesday, September 20, 2016
22
HIGH EFFICIENCY IEEE 802.3bt (PoE++, Type 3, 51W) PD WITH
K. HTOO
K. HTOO
N/A
LT4295IUFD, LT4321IUF
DEMO CIRCUIT 2539A-A
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. SCALE = NONE
www.linear.com
2
Tuesday, September 20, 2016
22
HIGH EFFICIENCY IEEE 802.3bt (PoE++, Type 3, 51W) PD WITH
K. HTOO
K. HTOO
N/A
LT4295IUFD, LT4321IUF
DEMO CIRCUIT 2539A-A
SIZE
DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. SCALE = NONE
www.linear.com
2
Tuesday, September 20, 2016
22
HIGH EFFICIENCY IEEE 802.3bt (PoE++, Type 3, 51W) PD WITH
K. HTOO
K. HTOO
N/A
LT4295IUFD, LT4321IUF
DEMO CIRCUIT 2539A-A
1
2
3
6
4
5
7
8
4 X 12nF
4 X 75 Ohms
1nF 2kV
J1
7499511001A
TRD1+ 11
TRCT1 12
TRD1- 10
TRD2+ 4
TRCT2 6
TRD2- 5
TRD3+ 3
TRCT3 1
TRD3- 2
TRD4+ 8
TRCT4 7
TRD4- 9
VC2 14
VC1 13
VC3 15
VC4 16
SHIELD
17 SHIELD
18
CT36
D3
MMSZ5252BS
24V
2 1
CG1
1000pF
1808
2KV
Q17
PSMN075-100MSE
6
4
5
8
7
1
2
3
D2
PTVS58VS1UR
2 1
Q11
PSMN075-100MSE
6
4
5
8
7
1
2
3
CT45
RT4
75
CT78
R28
0
Q18
PSMN075-100MSE
6
4
5
8
7
1
2
3
CG2
0.01uF
100V
1206
Q12
PSMN075-100MSE
6
4
5
8
7
1
2
3
Q13
PSMN075-100MSE
6
4
5
8
7
1
2
3
J2
SS-6488S-A-NF
1
2
3
4
5
6
7
8
910
Q14
PSMN075-100MSE
6
4
5
8
7
1
2
3
C11
0.047uF
100V
Q15
PSMN075-100MSE
6
4
5
8
7
1
2
3
RT1
75
Q16
PSMN075-100MSE
6
4
5
8
7
1
2
3
RT3
75
EP
U3
LT4321IUF
TG36
1
IN36
2
IN45
3
TG45
4
TG78
5
IN78
6
BG78
7
BG45
8
OUTP 12
EN 11
EN 10
OUTN 9
TG12 16
IN12 15
BG12 14
BG36 13
17
OUTN
CT12
RT2
75
14
dc2539aafb
DEMO MANUAL
DC2539A-A
© LINEAR TECHNOLOGY CORPORATION 2016
LT 0517 REV B • PRINTED IN USA
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions:
This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT
OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete
in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety
measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union
directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations.
If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date
of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU
OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS
FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR
ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims
arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all
appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or
agency certified (FCC, UL, CE, etc.).
No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance,
customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.
LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive.
Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and
observe good laboratory practice standards. Common sense is encouraged.
This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC application
engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
