1
dc2476aafb
DEMO MANUAL DC2476A-A
Description
LT4295, LT4321
High Efficiency IEEE 802.3bt (PoE++, Type 4, 62W/71W) PD
with Flyback DC/DC Converter and Auxiliary Supply Input
Demonstration Circuit 2476A is an IEEE 802.3bt (Draft2.2)
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 IEEE 802.3af (PoE, Type 1), IEEE
802.3at (PoE+, Type 2), and IEEE 802.3bt (PoE++, Type 3
and 4) compliant interfacing and power supply control. It
utilizes an external, low RDS(on) (30mΩ 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, LTPoE++ and the Linear logo are registered trademarks of
Analog Devices, Inc. All other trademarks are the property of their respective owners.
performance summary
BoarD photo
delivery efficiency and ease thermal design. This solution
replaces the eight diodes typically found in a passive PoE
rectifier bridge.
The DC2476A-A accepts up to 71W of delivered power
from a power sourcing equipment (PSE) via the RJ45
connector (J1) or a local 48V DC power supply using the
auxiliary supply input. When both supplies are connected,
the auxiliary supply input has priority over the PoE input.
The DC2476A-A supplies a 24V output at up to 2.7A.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2476A-A
PARAMETER CONDITIONS VALUE
Port Voltage (VPORT) At RJ45 37V to 57V
Auxiliary Voltage From AUX+ to AUX– Terminals 37V to 57V
Output Voltage (VOUT) 24V (Typical)
Output Current (IOUT) 2.7A (Max)
Output Voltage Ripple VPORT = 41.2V, IOUT = 2.7A 200mVP-P (Typical)
Load Regulation 0.5% (Typical)
Efficiency VPORT = 50V, IOUT = 2.7A, End-to-End 91.5% (Typical)
Switching Frequency 250kHz (Typical)
Top Side Bottom Side
2
dc2476aafb
DEMO MANUAL DC2476A-A
typical performance characteristics
Figure 1. Thermal Pictures (Conditions: VPORT=57V, VOUT=24V, IOUT=2.7A)
Figure 2. Efficiency (End-to-End) Figure 3. Load Regulation
Top Side Bottom Side
3
dc2476aafb
DEMO MANUAL DC2476A-A
typical performance characteristics
Figure 4. Switch Node Waveforms (Conditions: VPORT=57V, VOUT=24V, IOUT=2.7A)
4
dc2476aafb
DEMO MANUAL DC2476A-A
typical performance characteristics
Figure 5. Output Voltage Ripple (Conditions: VPORT=41.2V, VOUT=24V, IOUT=2.7A)
5
dc2476aafb
DEMO MANUAL DC2476A-A
typical performance characteristics
Figure 6. Load Transient Response (Conditions: VPORT=41.2V, Load Step: 1.35A to 2.7A to 1.35A)
6
dc2476aafb
DEMO MANUAL DC2476A-A
typical performance characteristics
Figure 7. Gain and Phase Margin of the Flyback DC/DC Converter (Conditions: VPORT=57V, VOUT=24V, IOUT=2.7A)
CROSSOVER FREQUENCY GAIN MARGIN PHASE MARGIN
3.8kHz 18dB 64°
7
dc2476aafb
DEMO MANUAL DC2476A-A
Quick start proceDure
Power over Ethernet (PoE) Input
1. Disconnect auxiliary supply if it is connected to AUX+
and AUX– inputs of the DC2476A-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 DC2476A using a
CAT5e or CAT6 Ethernet cable. (See Note.)
5. After the LED (D4) on the DC2476A is lit, check the
output voltage using a voltmeter. Output voltage should
be within 24.0V±0.3V.
6. Turn on the electronic load and increase its load cur-
rent up to 2.7A. 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 connected
to the DC2476A-A is provided in Table 1.
Note: An 802.3bt PSE has not yet been released. In the
interim, an LTPoE++
®
compliant PSE (DC1814A-D)
may be used to provide power to the DC2476A-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 DC2476A-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
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
75% Logic High/25% Logic Low, Toggle at 976Hz ±7% 71W
LTPoE++, 90W Logic Low 71W
VOLT
METER
+
–AM
METER
+
–
ELECTRONIC
LOAD
+
–
OSCILLOSCOPE
+
–
DC2476AA F09
IEEE 802.3bt
PSE
CAT5e
OR CAT6
CABLE
+
–
DC POWER
SUPPLY
+
–
8
dc2476aafb
DEMO MANUAL DC2476A-A
Quick start proceDure
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
DC2476A as shown in Figure 9. Turn on the auxiliary
supply and set its current limit to 2A. Then increase its
output voltage to 48V.
4. Once the LED (D4) on the DC2476A is lit, check the
output voltage using a voltmeter. Output voltage should
be within 24.0V ±0.3V.
5. Turn on the electronic load and increase its load cur-
rent up to 2.7A. 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%.
Figure 9. Setup Diagram for Auxiliary Supply Input
VOLT
METER
+
–AM
METER
+
–
ELECTRONIC
LOAD
+
–
OSCILLOSCOPE
+
–
AUXILIARY
SUPPLY
+–
DC2476AA F09
9
dc2476aafb
DEMO MANUAL DC2476A-A
parts list
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
DC2476A General BOM
1 2 CG1, CG2 CAP, CER, X7R 1000pF 2kV 10% 1808 MURATA, GR442QR73D102KW01L
2 4 CT1, CT2, CT3, CT4 CAP, CER, X7R 0.01µF 100V 20% 0805 MURATA, GRM21BR72A103MA01L
3 0 C1 CAP, CER, OPT 2kV 1812 OPT
4 1 C6 CAP, ELEC, 22µF 100V 10% 8x10.2 SUNCON, 100CE22KX
5 2 C7, C29 CAP, CER, X7R 2.2µF 100V 10% 1210 MURATA, GRM32ER72A225KA35
6 1 C10 CAP, CER, X7R 10nF 100V 20% 0603 MURATA, GRM188R72A103KA01D
7 1 C11 CAP, CER, X7R 0.047µF 100V 20% 0603 KEMET, C0603C473M1RACTU
8 1 C12 CAP, CER, X7R 0.047µF 100V 10% 0805 MURATA, GRM21BR72A473KA01L
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 C24 CAP, CER, X7R 0.1µF 25V 20% 0603 MURATA, GRM188R71E104KA01D
14 1 C26 CAP, CER, X7R 100pF 16V 10% 0402 AVX, 0402YC101KAT2A
15 0 C27 CAP, CER, X7R OPT 6.3V 10% 0402 OPT
16 1 C30 CAP, CER, X7R OPT 250V 10% 1206 AVX, 12061C103MAT2A
17 1 D1 DIODE, SCHOTTKY, PDS5100H 100V POWERDI5 DIODES INC, PDS5100H
18 3 D2, D16, D19 DIODE, TVS, PTVS58VS1UR 58V SOD123 NXP, PTVS58VS1UR
19 1 D3 DIODE, ZENER, MMSZ5252BS 24V SOD323 DIODES INC, MMSZ5256BS
20 1 D13 DIODE, SCHOTTKY, BAT46WJ, 115 100V SOD323 NXP, BAT46WJ, 115
21 1 D15 DIODE, BAV19WS 120V SOD323 DIODES 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 ISO1 OPTO, TLP291(GR-TP, E) TOSHIBA, TLP291(GR-TP, E)
25 2 J1, J2 CONN, RJ-45, SS-6488-NF-K1 STEWART CONNECTOR, SS-6488-NF-K1
26 4 J3, J4, J5, J6 CONN, BANANA JACK KEYSTONE, 575-4
27 1 L2 IND, 4.7µH WURTH, 744316470
28 1 L3 IND, CMC, 3.5mH, PCA, EPZ3109G-LF
29 1 L4 IND, 100µH COILCRAFT, DO1608C-104MLB
30 0 L6 IND, OPT OPT
10
dc2476aafb
DEMO MANUAL DC2476A-A
parts list
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
31 1 Q1 MOSFET, N-CH, PSMN040-100MSE 100V 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, FMMT723
35 8 Q11, Q12, Q13, Q14, Q15,
Q16, Q17, Q18
MOSFET, N-CH, PSMN040-100MSE 100V LFPAK33 NXP, PSMN040-100MSE
36 8 RT1, RT2, RT3, RT4, RT5,
RT6, RT7, RT8
RES, CHIP, 75Ω 5% 0603 PANASONIC, ERJ-3GEYJ750V
37 1 R5 RES, CHIP, 8.2Ω 5% 0805 PANASONIC, ERJ-P6WJ8R2J
38 1 R6 RES, CHIP, 3.3K 5% 0603 VISHAY, CRCW06033K30FKEA
39 1 R7 RES, CHIP, 20Ω 5% 0805 VISHAY, CRCW080520R0JNEA
40 2 R12, R28 RES, CHIP, 0 5% 0603 PANASONIC, ERJ-3GEY0R00V
41 1 R13 RES, CHIP, 100Ω 5% 0603 PANASONIC, ERJ-3GEYJ101V
42 1 R15 RES, CHIP, 15Ω 5% 0603 VISHAY, CRCW060315R0FKEA
43 1 R17 RES, CHIP, 2.00K 1% 0603 VISHAY, CRCW06032K00FKEA
44 1 R18 RES, CHIP, 10K 5% 0603 VISHAY, CRCW060310K0JNEA
45 1 R21 RES, CHIP, 174K 1% 0603 VISHAY, CRCW0603174KFKEA
46 1 R22 RES, CHIP, 107K 5% 0603 VISHAY, CRCW0603107KFKEA
47 2 R27, R31 RES, CHIP, 0Ω SHUNT 0402 VISHAY, CRCW04020000Z0EA
48 1 R29 RES, CHIP, 52.3K 1% 0603 PANASONIC, ERJ-3EKF5232V
49 0 R32 RES, CHIP, OPT 1% 1812 OPT
50 0 R33 RES, CHIP, OPT 5% 0805 OPT
51 1 R34 RES, CHIP, 0Ω SHUNT 0603 PANASONIC, ERJ-3GEY0R00V
52 1 T3 XFMR, SMD GATE DRIVE, PE-68386NL PULSE, PE-68386NL
53 0 T3 (ALTERNATE) XFMR, SMD GATE DRIVE, EPA4271GE-LF PCA, EPA4271GE-LF
54 1 T4 TRANSFORMER, ETHERNET, 749022016 WURTH, 749022016
55 0 T4 (ALTERNATE) TRANSFORMER, ETHERNET, ETH1-460LD COILCRAFT, ETH1-460LD
56 0 T4 (ALTERNATE) TRANSFORMER, ETHERNET, EPG4260S-LF PCA, EPG4260S-LF
57 1 U1 IC, PD & SWITCHER CONTROLLER, LT4295IUFD QFN28 LINEAR TECH, LT4295IUFD#PBF
58 1 U3 IC, POE IDEAL BRIDGE CONTROLLER, LT4321IUF QFN16 LINEAR TECH, LT4321IUF#PBF
59 4 MH1-MH4 STAND-OFF, NYLON 0.50" TALL (SNAP ON) KEYSTONE, 8833
60 2 STENCILS (TOP & BOTTOM) STENCIL, DC2476A
11
dc2476aafb
DEMO MANUAL DC2476A-A
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
DC2476A-A
1 1 C2 CAP, CER, X5R 10µF 50V 10% 1210 MURATA, GRM32ER61H106KA12
2 0 C3 CAP, CER, X5R OPT 50V 10% 1210 OPT
3 1 C4 CAP, ELEC, 47µF 35V 20% PANASONIC, EEE-FK1V470P
4 0 C5 CAP, ELEC, OPT 35V 20% OPT
5 1 C8 CAP, CER, U2J 330pF 630V 5% 1206 MURATA, GRM31A7U2J331JW31
6 1 C9 CAP, CER, U2J 220pF 630V 5% 1206 MURATA, GRM31A7U2J221JW31
7 1 C16 CAP, CER, X7R 0.1µF 25V 10% 0805 MURATA, GRM21BR71E104KA01L
8 1 C22 CAP, CER, X7R 3.3nF 25V 10% 0603 MURATA, GRM188R71E332KA01D
9 1 C23 CAP, CER, X7R 4.7nF 2kV 1812 MURATA, GR443DR73D472KW01L
10 1 C25 CAP, CER, X7R 330pF 25V 10% 0603 AVX, 06033C331KAT2A
11 0 D18 DIODE, DIODE INC, OPT 30V SOD323 OPT
12 1 L5 IND, 1µH WURTH, 744316100
13 1 Q2 MOSFET, N-CH, BSC320N20NS3 200V SUPERSO8 INFINEON, BSC320N20NS3
14 1 Q4 MOSFET, N-CH, BSC190N15NS3 150V SUPERSO8 INFINEON, BSC109N10NS3 G
15 2 R3, R4 RES, CHIP, 51Ω 5% 2010 VISHAY, CRCW201051R0JNEF
16 2 R8, R9 RES, CHIP, 36Ω 5% 2010 PANASONIC, ERJ-12ZYJ360U
17 1 R10 RES, CHIP, 3.65K 1% 0603 VISHAY, CRCW06033K65FKEA
18 1 R11 RES, CHIP, 5.23K 5% 0603 VISHAY, CRCW06035K23FKEA
19 1 R14 RES, CHIP, 15mΩ 1% 2010 VISHAY, WSL2010R0150FEA
20 1 R16 RES, CHIP, 0Ω SHUNT 0805 VISHAY, CRCW08050000Z0EA
21 1 R19 RES, CHIP, 118Ω 1% 0805 PANASONIC, ERJ-6ENF1180V
22 1 R20 RES, CHIP, 52.3 1% 0805 VISHAY, CRCW080552R3FKEA
23 1 R23 RES, CHIP, 36K 5% 0603 VISHAY, CRCW060336K0FKEA
24 1 R24 RES, CHIP, 51K 5% 0603 VISHAY, CRCW060351K0JNEA
25 1 R25 RES, CHIP, 20K 5% 0603 PANASONIC, ERJ-3EKF2002V
26 1 R26 RES, CHIP, 4.7K 5% 0603 YAGEO, RC0603JR-074K7L
27 0 R30 RES, CHIP, OPT 5% 0805 OPT
28 0 R35 RES, CHIP, OPT 5% 2010 OPT
29 1 T1 XFMR, PWR TRAN, EPC3630G-LF PCA, EPC3630G-LF
30 0 T1 (ALTERNATE) XFMR, PWR TRAN, 750316231 WURTH, 750316231
31 1 FAB, PRINTED CIRCUIT BOARD DEMO CIRCUIT 2476A
parts list
12
dc2476aafb
DEMO MANUAL DC2476A-A
schematic Diagram
5
5
4
4
3
3
2
2
1
1
D
D
C
C
B
B
A
A
T2P
-VOUT
+VOUT
___
GND
37V-57V
24V/2.7A
DC-DC CONVERTER WITH AUXILIARY POWER INPUT
*CHANGE R19 TO 64.9 OHM AND R20 TO 80.6 OHM
TO MAKE THE DC2476A CLASSIFY AS 62W PD.
OPTIONAL COMPONENTS
+VOUT
+VOUT
VPORTP
+VOUT
VCC
VCC
VPORTP
VPORTN
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
KAUNG H.
PRODUCTION1 1 9-6-2016
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
KAUNG H.
PRODUCTION1 1 9-6-2016
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
KAUNG H.
PRODUCTION1 1 9-6-2016
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
1
Wednesday, August 02, 2017
12
HIGH EFFICIENCY IEEE 802.3bt (TYPE 4) PD WITH FLYBACK
N/A
LT4295IUFD, LT4321IUF
K. HTOO
K. HTOO
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
1
Wednesday, August 02, 2017
12
HIGH EFFICIENCY IEEE 802.3bt (TYPE 4) PD WITH FLYBACK
N/A
LT4295IUFD, LT4321IUF
K. HTOO
K. HTOO
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
1
Wednesday, August 02, 2017
12
HIGH EFFICIENCY IEEE 802.3bt (TYPE 4) PD WITH FLYBACK
N/A
LT4295IUFD, LT4321IUF
K. HTOO
K. HTOO
0.1uF
C16
0805
C3
OPT
J4
E12
D19
PTVS58VS1UR
2 1
OPT
L6
D18
OPT
21
330pF
C8
1206
R13
100
R19*
118
0805
2.2uF
100V
1210
X7R
C7
100pF
C26
25V
1uH
L5
744316100
D15
BAV19WS
2 1
R8
36
2010
2.2uF
100V
1210
X7R
C29
R16
0
0805
R7
20
0.047uF
C12
100V
1uF
C17
OPT
C27
6.3V
D16
PTVS58VS1UR
2 1
E3
R31
0
PE-68386NL
T3
1
3
6
4
J5
R11
5.23K
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
D13
BAT46WJ,115
12
R30
OPT
0805
R29
52.3K
100uH
L4
DO1608C-104
4.7uH
L2
WURTH
744316470
ISO1
TLP291(GR-TP,E)
12
43
330pF
C25
E5
PBSS5140T
Q5
1
23
R22
107K
R17
2.00K
C10
10nF
100V
R5
8.2
0805
E2
R14
15m
2010
+
22uF
100V
8x10.2
C6
R12
0
PDS5100H
D1
2
1
3
L3
3.5mH
EPZ3109G
4 3
21
D4
LED
R34
0
Q2
BSC320N20NS3
200V
6
4
5
8
7
1
2
3
HSS
R3
51
2010
OPT
C15
Q1
PSMN040-100MSE
6
4
5
8
7
1
2
3
OPT
C21
R15
15
J6
4.7nF
C23
+
C5
OPT
T1
EPC3630G-LF
1
11
86
4
7
12
5
2
3
R33
OPT
R4
51
2010
R25
20K
0.1uF
C24
R20*
52.3
0805
R18
10K
Q7
FMMT723
3 2
1
E11
R24
51K
OPT
C19
R35
OPT
E6
R21
174K
J3
+
C4
35V
47uF
EEE-FK1V470P
3.3nF
C22
R9
36
2010
R27
0
C2
X5R
50V
1210
10uF
2.2nF
C20
R26
4.7K
PBSS4140T
Q6
1
2 3
220pF
C9
1206
Q4
BSC190N15NS3
150V
6
4
5
8
7
1
2
3
OPT
C1
R32
OPT
R23
36K
R2
3K
R10
3.65K
R6
3.3K
10uF
C13
10V
1206
OPT
C18
D17
PMEG1020EA
2 1
VPRI_SG
SG
VPRI_SW
PG
VSEC_SW
VPRI_P
VSEC_SG
VSEC_P
PG
VAUX_P
FB
FB VSEC_P
13
dc2476aafb
DEMO MANUAL DC2476A-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
DC-DC CONVERTER AND AUXILIARY POWER INPUT
VPORTN
VPORTP
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
KAUNG H.
PRODUCTION1 1 9-6-2016
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
KAUNG H.
PRODUCTION1 1 9-6-2016
REVISION HISTORY
DESCRIPTION DATEAPPROVEDECO REV
KAUNG H.
PRODUCTION1 1 9-6-2016
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
1
Tuesday, November 15, 2016
22
HIGH EFFICIENCY IEEE 802.3bt (TYPE 4) PD WITH FLYBACK
K. HTOO
K. HTOO
N/A
LT4295IUFD, LT4321IUF
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
1
Tuesday, November 15, 2016
22
HIGH EFFICIENCY IEEE 802.3bt (TYPE 4) PD WITH FLYBACK
K. HTOO
K. HTOO
N/A
LT4295IUFD, LT4321IUF
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
1
Tuesday, November 15, 2016
22
HIGH EFFICIENCY IEEE 802.3bt (TYPE 4) PD WITH FLYBACK
K. HTOO
K. HTOO
N/A
LT4295IUFD, LT4321IUF
CT12
RT3
75
J2
SS-6488-NF-K1
1
2
3
4
5
6
7
8
910
CT2
0.01uF
100V
0805
Q16
PSMN040-100MSE
6
4
5
8
7
1
2
3
CT1
0.01uF
100V
0805
R28
0
Q18
PSMN040-100MSE
6
4
5
8
7
1
2
3
Q17
PSMN040-100MSE
6
4
5
8
7
1
2
3
CT4
0.01uF
100V
0805
Q15
PSMN040-100MSE
6
4
5
8
7
1
2
3
RT7
75
RT2
75
RT5
75
CT45
C11
0.047uF
100V
CG1
1000pF
2KV
1808
0.01uF
C30
1206
Q14
PSMN040-100MSE
6
4
5
8
7
1
2
3
D3
MMSZ5252BS
24V
2 1
RT4
75
Q11
PSMN040-100MSE
6
4
5
8
7
1
2
3
Q12
PSMN040-100MSE
6
4
5
8
7
1
2
3
Q13
PSMN040-100MSE
6
4
5
8
7
1
2
3
CT3
0.01uF
100V
0805
CG2
1000pF
2KV
1808
CT78
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
J1
SS-6488-NF-K1
1
2
3
4
5
6
7
8
910
RT6
75
RT1
75
RT8
75
D2
PTVS58VS1UR
2 1
CT36
T4 749022016
D- 3
TD 1
X+
14
X-
16
D+ 11
D- 9
D- 6
D+ 8
X-
13
TD 4
D+ 5
D+ 2
TX
15 TD 10
TD 7
D- 12
TX
18
X+
17
X-
19
TX
21
X+
20
X-
22
TX
24
X+
23
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
POE_CT12
POE_CT78
POE_CT45
Shield
POE_CT36
Shield
14
dc2476aafb
DEMO MANUAL DC2476A-A
LINEAR TECHNOLOGY CORPORATION 2016
LT 0817 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