DC1814A - Demo Manual

DEMO MANUAL
DC1814A
LTC4274A
Single LTPoE++ PSE Controller
Description
Demonstration circuit 1814A features the LTC®4274A,
single port power sourcing equipment (PSE) controller,
capable of delivering up to 90W of LTPoE++® power to a
compatible LTPoE++ powered device (PD). A proprietary
detection/classification scheme allows mutual identification between an LTPoE++ PSE and LTPoE++ PD while
remaining compatible and interoperable with existing
Type 1 (13W) and Type 2 (25.5W) PDs. The LTC4274A
feature set is a superset of the popular LTC4274. These
PSE controllers utilize low RON external MOSFETs and
0.25Ω sense resistors which are especially important at
the LTPoE++ current levels to maintain the lowest possible
heat dissipation.
The LTC4274A is available in multiple power grades,
allowing delivered PD power of 13W, 25.5W, 38.7W,
52.7W, 70W and 90W. The DC1814A has four variations
DC1814A-A, DC1814A-B, DC1814A-C, and DC1814A-D
which accommodate the LTPoE++ power levels (Table 1).
The LTC4274A is configured in the DC1814A as an AUTO
pin high, MID pin high, autonomous midspan power injector; input data from an existing network system is sent out,
along with power, to a PD. The LTC4274A autonomously
detects a PD, turns power on to the port, and disconnects
port power without the need for a microcontroller. A single
55V supply is required to power the DC1814A. A simple
LDO regulator circuit on the board powers the digital supply of the LTC4274A. A SHDN pushbutton shuts down the
port and disables detection. A RESET pushbutton resets
the LTC4274A to the AUTO pin high state.
Design files for this circuit board are available at
http://www.linear.com/demo/DC1814A
L, LT, LTC, LTM, LTPoE++, Linear Technology and the Linear logo are registered trademarks of
Linear Technology Corporation. All other trademarks are the property of their respective owners.
Table 1. DC1814A Power Levels
DEMO BOARD
PSE CONTROLLER
MAXIMUM DELIVERED PD POWER
POWER SUPPLY*
DC1814A-A
LTC4274A-1
38.7W
72W
DC1814A-B
LTC4274A-2
52.7W
72W
DC1814A-C
LTC4274A-3
70W
120W
DC1814A-D
LTC4274A-4
90W
140W
*Recommended DC1814A power supply minimum to avoid drooping in a worst-case scenario with ILIM current at the port. Set the voltage between
54.75V to 57V for LTPoE++ compliance.
dc1814afe
1
DEMO MANUAL
DC1814A
Quick Start Procedure
Demonstration circuit 1814A is easy to set up for evaluating the performance of the LTC4274A. Refer to Figure 1
for proper test equipment setup and follow the procedure
below.
1.Connect a 55V to 57V power supply across AGND (+)
and VEE (–). Size the power supply considering the
maximum power delivered to the PD.
2. Connect an 802.3 Type 1 or Type 2, or LTPoE++ compatible PD to RJ45 connector J1 with an Ethernet cable.
3.Measure the port output voltage to the PD across
VPORT+ and VPORT– test points.
4.(Optional) Connect a PHY to RJ45 connector J2 with
an Ethernet cable for data tests.
Figure 1. DC1814A Setup
2
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DEMO MANUAL
DC1814A
Board Layout
The power path is from VEE to the sense resistor, to the
MOSFET, and out to the port. Select a trace width appropriate for the maximum current.
Proper components placement and board layout with
respect to the LTC4274A is important to provide electrical
robustness and correct operation. The following mentioned
components, also shown in Figure 2, must be close to their
respective LTC4274A pins with no other components in
between on the connection path. Place a 0.1µF capacitor
(C1) directly across the LTC4274A VDD and DGND pins.
Place a 1µF, 100V capacitor (C4) and a SMAJ58A TVS (D3)
directly across the LTC4274A AGND and VEE pins. Place
a 0.22µF, 100V capacitor (C5) directly to the OUT pin and
an AGND plane.
VDD
18
D3
SMAJ58A
19 22 25 26 27 39
C4
0.1µF
100V
GATE
DGND
DGND
DGND
DGND
VEE
VEE
VEE
VEE
VEE
VEE
10
15
16
17
AGND
DGND
30
31
CSRN2512FKR250
32
C5
0.22µF
100V
RS1
0.25Ω
VEE
OUT
U1
LTC4274AIUHF
C1
0.1µF
SENSE
13
VDD
Kelvin sensing is necessary to provide accurate current
readings. The sense resistor used with the LTC4274A must
be 0.25Ω, 1% or better, and with a power rating that can
handle the maximum DC current passed through it. A
dedicated sense trace from the SENSE pin of the LTC4274A
must go directly to the sense resistor solder pad. Avoid
connecting to copper cutouts and other traces. The VEE
side of the sense resistor must also connect to the VEE
pins of the LTC4274A either through a direct trace (Figure
3A), or a VEE copper plane (Figure 3B), without any other
components in between on this connection.
Q1
FDMC86102
OUT
DC1814A F02
Figure 2. LTC4274A Key Application Components for Board Placement
Figure 3. LTC4274IUHF VEE and SENSE Kelvin Connection to Sense Resistor
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3
DEMO MANUAL
DC1814A
Supply Voltages
The LTC4274A also requires a digital 3.3V supply. The
DC1814A uses a simple LDO regulator circuit to power the
3.3V digital supply from the VEE supply. The LTC4274A VDD
supply is allowed to be within 5V above or below AGND. On
the DC1814A, VDD is tied to AGND and DGND is a negative
voltage below AGND. D1, R5, Q2, and R11 generate the
negative voltage referenced to AGND (Figure 4). These
components are sized to handle the power required to
supply the LTC4274A and LEDs on the DC1814A. Contact
Linear Technology Applications for 3.3V options.
Surge Protection
Ethernet ports can be subject to significant cable surge
events. To keep PoE voltages below a safe level and protect
the application against damage, protection components
are required at the main supply, at the LTC4274A supply
pins and at the port. Refer to Figure 5.
R10
1Ω
D23
5.6V
DGND
Q2
CMPTA92
In a high surge environment, a 10Ω, 0805 resistor in series
from supply AGND to the LTC4274A AGND and VDD pin is
recommended. The bulk TVS and capacitance remain on
the supply side of this 10Ω resistor. The LTC4274A supply
pins local TVS and capacitance remain at the LTC4274A
side of this 10Ω resistor.
The port requires a pair of S1B clamp diodes: one from
OUT to supply AGND and one from supply VEE to OUT. The
diodes at the ports steer harmful surges into the supply
rails where they are absorbed by the surge suppressors
and the VEE bypass capacitance. The layout of these paths
must be low impedance.
13
VDD
U1
LTC4274AIUHF
C1
0.1µF
10
15
16
17
DGND
DGND
DGND
DGND
AGND
D1
3.8V
MMSZ4686T1
Bulk transient voltage suppression devices and bulk
capacitance are required across the main PoE supply
and should be sized to accommodate system level surge
requirements. Across the LTC4274A AGND pin and VEE
pin are an SMAJ58A, 58V TVS and a 1μF, 100V bypass
capacitor. These components must be placed close to the
LTC4274A pins.
VEE
VEE
VEE
VEE
VEE
VEE
Select a VEE supply with enough power to sustain the port
at maximum load. Table 1 shows the maximum delivered
PD power as well as a recommended VEE power supply
minimum to avoid drooping in a worst case scenario with
ILIM current.
18 19 22 25 26 27 39
R5
100k
R11
1k
1/4W
VEE
DC1814A F04
Figure 4. DC1814A LDO Circuit for the LTC4274A Digital Supply
4
dc1814afe
DEMO MANUAL
DC1814A
Supply Voltages
10
15
16
17
DGND
DGND
DGND
DGND
R5
100k
18
R11
1k
1/4W
D3
SMAJ58A
19 22 25 26 27 39
C4
1µF
100V
30
31
CSRN2512FKR250
32
C5
0.22µF
100V
RS1
0.25Ω
VEE
OUT
Q2
CMPTA92
U1
LTC4274AIUHF
C1
0.1µF
GATE
VEE
D23
5.6V
VDD
SENSE
D1
3.9V
MMSZ4686T1
CBULK
13
VEE
VEE
VEE
VEE
VEE
VEE
TVSBULK
R10
1Ω
AGND
10Ω
0805
D4
S1B
OUT
Q1
FDMC86102
D5
S1B
VEE
DC1814A F05
Figure 5. High Surge Environment Recommended LTC4274A Protection
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5
DEMO MANUAL
DC1814A
PCB Layout
6
Top Silkscreen
Layer 1. Top Layer
Layer 2. –VIN 1
Layer 3. –VIN 2
Layer 4. Bottom Layer
Bottom Silkscreen
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DEMO MANUAL
DC1814A
Parts List
ITEM
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
DC1814A-A
1
2
3
4
DC1814A-B
1
2
3
4
DC1814A-C
1
2
3
4
DC1814A-D
1
2
3
4
QTY
1
1
1
1
2
4
2
1
1
1
1
4
4
2
2
1
4
1
8
1
1
4
2
1
1
1
REFERENCE
C1
C2
C5
C4
C3, C6
CT1-CT4
D4, D5
D3
D2
D1
D23
E1-E4
F7-F10
J3, J4
J1, J2
R10
R6-R9
R5
R1-R4, RT1-RT4
R11
RS1
MH1-MH4
SW1, SW2
Q1
Q2
T1
PART DESCRIPTION
CAP, 0603 0.1µF 10% 25V X7R
CAP, 4.7µF 20% 63V ALUM.
CAP, 1206 0.22µF 20% 100V X7R
CAP, 1210 1.0µF 10% 100V X7R
CAP, 1808 1000pF 10% 2KV X7R
CAP, 0805 0.01µF 5% 100V X7R
DIODE, RECTIFIER, 100V 1A, SMA
DIODE, TVS 58V 400W SMA
DIODE, TVS, 64V 600W SMB
DIODE, ZENER 3.9V SOD-123
DIODE, ZENER 5.6V 5% SOT23
TESTPOINT, TURRET, 0.094" PBF
FUSE, 3A, 63VDC 1206
CONN, JACK, BANANA
CONN, RJ45, SINGLE PORT
RES, 0603 1.0Ω 5% 1/10W
RES, 0603 10k 5% 1/10W
RES, 0603 100k 5% 1/10W
RES, 0603 75Ω 5% 1/10W
RES, THICK FILM 0805 1.0k 5% 1/4W
RES, 2512 0.25Ω 1% 2W
STAND-OFF, NYLON 0.75"
SWITCH, MOMENTARY PUSHBUTTON
XSTR, MOSFET, N-CHANNEL 100V 2.3A POWER-33
XSTR, PNP, 300V 500MA SOT23 CMPTA92
XFMR, POE+ 1.5A
(Option)
MANUFACTURER/PART NUMBER
TDK C1608X7R1E104K (BAL. FR#1807)
PANASONIC, EEEFK1J4R7R
AVX 12061C224MAT
AVX, 12101C105KAT
TDK C4520X7R3D102K
AVX 08051C103JAT
VISHAY S1B
DIODES INC., SMAJ58A-13-F
DIODES INC., SMBJ64A-13-F
ON SEMI MMSZ4686T1G
FAIRCHILD, BZX84C5V6
MILL-MAX, 2501-2-00-80-00-00-07-0
BEL FUSE C1Q 3
KEYSTONE 575-4
STEWART CONN., SS-7188S-A-NF
VISHAY CRCW06031R00JNEA
YAGEO, RC0603JR-0710KL
YAGEO, RC0603JR-07100KL
YAGEO, RC0603JR-0775RL
PANASONIC, ERJ-P06J102V
STACKPOLE, CSRN2512FKR250
KEYSTONE, 8834(SNAP ON)
WÜRTH, 434 123 050 816
FAIRCHILD FDMC86102
CENTRAL SEMI CMPTA92
WÜRTH ELECTRONICS, 749022016
COILCRAFT ETH1-460L
1
4
1
1
DC1814A
FB1-FB4
U1
GENERAL BOM
FERRITE BEAD, 1k, 0805
IC, LTC4274A-1, SINGLE PORT 38.7W PSE CONTROLLER
FAB, PRINTED CIRCUIT BOARD
TDK MPZ2012S102A
LINEAR LTC4274AIUHF-1
DEMO CIRCUIT 1814A
1
4
1
1
DC1814A
FB1-FB4
U1
GENERAL BOM
FERRITE BEAD, 1k, 0805
IC, LTC4274A-2, SINGLE PORT 52.7W PSE CONTROLLER
FAB, PRINTED CIRCUIT BOARD
TDK MPZ2012S102A
LINEAR LTC4274AIUHF-2
DEMO CIRCUIT 1814A
1
4
1
1
DC1814A
FB1-FB4
U1
GENERAL BOM
FERRITE BEAD, 1k, 0805
IC, LTC4274A-3, SINGLE PORT 70W PSE CONTROLLER
FAB, PRINTED CIRCUIT BOARD
TDK MPZ2012S102A
LINEAR LTC4274AIUHF-3
DEMO CIRCUIT 1814A
1
4
1
1
DC1814A
FB1-FB4
U1
GENERAL BOM
FERRITE BEAD, 1300Ω, 1812
IC, LTC4274A-4, SINGLE PORT 90W PSE CONTROLLER
FAB, PRINTED CIRCUIT BOARD
TAIYO YUDEN FBMH4532HM132-T
LINEAR LTC4274AIUHF-4
DEMO CIRCUIT 1814A
dc1814afe
7
A
B
C
D
J3
VEE
(-)
J4
(55V TO 57V)
MAIN PS
INPUTS
(+)
AGND
E2
E1
5
4.7uF
63V
C2
SMBJ64A
D2
+
VEE
D1
3.9V
MMSZ4686T1
1
1
100K
R5
D23
5.6V
2
2
R11
1.0K
1/4W
10
15
16
17
C1
0.1uF
36
33
13
4
DGND
DGND
DGND
DGND
MID
AUTO
VDD
R7
10K
TP2
VDD
D3
SMAJ58A
Q2
CMPTA92
TP1
DGND
R10
1
SHDN
SW1
RESET
SW2
FOR HIGH SURGE ENVIRONMENTS
ADD A 10 OHM, 0805 RESISTOR
AT THIS LOCATION
2. INSTALL SHUNTS AS SHOWN.
1. ALL RESISTORS ARE IN OHMS, 0603.
ALL CAPACITORS ARE IN MICROFARADS, 0603.
4
R8
SCL
10K
R6
10K
RS1
0.25
CSRN2512FKR250
C4
1.0uF
100V
SDA
10K
R9
9
10
7
NOTE: UNLESS OTHERWISE SPECIFIED
3
1
14
18
MSD
35
RESET
34
SHDN
AGND
38
SCL
3
SDAIN
37
INT
VEE
VEE
VEE
VEE
VEE
VEE
19
22
25
26
27
39
1
SDAOUT
1
2
3
4
5
6
7
8
DNC
FDMC86102
Q1
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
R3
75
20
5
13
T1: WURTH 749022016
COILCRAFT ETH1-460L
15
14
12
16
9
11
10
18
17
8
7
19
6
21
22
4
24
23
3
T1
1
2
FB1
SEE TABLE
3
C5
0.22uF
100V
VEE
D5
S1B
D4
S1B
VPORT -
VPORT +
90W
-D
2
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
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.
JK
DILIAN R.
PCB DES.
APP ENG.
SCALE = NONE
C6
1000pF
2kV
CT4 0.01uF
0805 100V
CT3 0.01uF
0805 100V
CT2 0.01uF
0805 100V
U1
DATE:
N/A
SIZE
10
9
FB1, FB2, FB3, FB4
SS-7188S-A-NF
J1
DATE
9/26/11
3/28/13
12/8/15
4/29/11
TM
Tuesday, December 08, 2015
1
DEMO CIRCUIT 1814A
LTC4274AIUHF FAMILY
SHEET 1
PSE CONTROLLER
1
OF 1
REV.
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
FBMH4532HM132-T
MPZ2012S102A
MPZ2012S102A
MPZ2012S102A
SINGLE PORT LTPoE++
IC NO.
APPROVED
DATA AND POWER OUT
1
2
3
4
5
6
7
8
TECHNOLOGY
LTC4274AIUHF-4
LTC4274AIUHF-3
LTC4274AIUHF-2
TITLE: SCHEMATIC
1
DESCRIPTION
REVISION HISTORY
PRODUCTION
DILIAN R.
POWER LEVEL UPDATE DILIAN R.
T1 OPTION
DILIAN R.
DILIAN R.
SURGE RESISTOR
LTC4274AIUHF-1
F10
C1Q 3
3A, 1206
1
1a
1b
1c
REV
CT1 0.01uF
0805 100V
_
_
_
ECO
SEE TABLE
FB4
RT4
75
RT3
75
RT2
75
RT1
75
APPROVALS
70W
CUSTOMER NOTICE
52.7W
-C
38.7W
-WATT PSE
-B
-A
FB3
F9
C1Q 3
3A, 1206
F7
C1Q 3
3A, 1206
FB2
2
ASSEMBLY VERSION
E4
E3
NOTE: FOR TEMPERATURE SENSITIVE 90W
APPLICATIONS, TWO OF THE 749012013 MAY BE
F8
USED AS AN ALTERNATE TO T1 WHICH HAS A
C1Q 3
HIGHER CURRENT RATING
3A, 1206
C3
1000pF
2kV
R4
75
R2
75
R1
75
3
U1
LTC4274AIUHF
8
2
9
11
12
20
21
23
24
28
29
SS-7188S-A-NF
J2
DATA IN
5
AD1
6
AD0
SENSE
30
AD3
4
AD2
GATE
31
OUT
8
32
5
A
B
C
D
DEMO MANUAL
DC1814A
Schematic Diagram
dc1814afe
DEMO MANUAL
DC1814A
Assembly Drawing
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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
dc1814afe
9
DEMO MANUAL
DC1814A
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
10 Linear Technology Corporation
dc1814afe
LT 0116 REV E • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507 ● www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2011
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