Table of Contents
Advertisement
Quick Links
Description
Demonstration circuit 1814A features the
single port power sourcing equipment (PSE) controller,
capable of delivering up to 90W of LTPoE ++
compatible LTPoE ++ powered device (PD). A proprietary
detection/classification scheme allows mutual identifica-
tion 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 R
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).
Table 1. DC1814A Power Levels
DEMO BOARD
DC1814A-A
DC1814A-B
DC1814A-C
DC1814A-D
*Recommended DC1814A power supply minimum to avoid drooping in a worst-case scenario with I
54.75V to 57V for LTPoE ++ compliance.
Arrow.com.
Downloaded from
Single LTPoE ++ PSE Controller
LTC
4274A,
®
power to a
®
external MOSFETs and
ON
PSE CONTROLLER
LTC4274A-1
LTC4274A-2
LTC4274A-3
LTC4274A-4
DEMO MANUAL
The LTC4274A is configured in the DC1814A as an AUTO
pin high, MID pin high, autonomous midspan power injec-
tor; 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 sup-
ply 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.
MAXIMUM DELIVERED PD POWER
38.7W
52.7W
70W
90W
current at the port. Set the voltage between
LIM
DC1814A
LTC4274A
POWER SUPPLY*
72W
72W
120W
140W
dc1814afe
1
Advertisement
Table of Contents
Related Manuals for Linear Technology 1814A
Summary of Contents for Linear Technology 1814A
- Page 1 The LTC4274A is available in multiple power grades, L, LT, LTC, LTM, LTPoE ++ , Linear Technology and the Linear logo are registered trademarks of allowing delivered PD power of 13W, 25.5W, 38.7W, Linear Technology Corporation. All other trademarks are the property of their respective owners.
-
Page 2: Quick Start Procedure
Quick start proceDure 2. Connect an 802.3 Type 1 or Type 2, or LTPoE ++ compat- Demonstration circuit 1814A is easy to set up for evaluat- ing the performance of the LTC4274A. Refer to Figure 1 ible PD to RJ45 connector J1 with an Ethernet cable. -
Page 3: Board Layout
DEMO MANUAL DC1814A BoarD Layout The power path is from VEE to the sense resistor, to the Proper components placement and board layout with MOSFET, and out to the port. Select a trace width appro- respect to the LTC4274A is important to provide electrical priate for the maximum current. -
Page 4: Supply Voltages
LTC4274A and LEDs on the DC1814A. Contact The port requires a pair of S1B clamp diodes: one from Linear Technology Applications for 3.3V options. OUT to supply AGND and one from supply VEE to OUT. The diodes at the ports steer harmful surges into the supply... - Page 5 DEMO MANUAL DC1814A suppLy VoLtages 10Ω 0805 LTC4274AIUHF BULK BULK 3.9V 5.6V 0.1µF MMSZ4686T1 DGND DGND DGND DGND CMPTA92 25 26 27 39 100k 1µF SMAJ58A 0.22µF 100V 1/4W 100V 0.25 CSRN2512FKR250 FDMC86102 DC1814A F05 Figure 5. High Surge Environment Recommended LTC4274A Protection dc1814afe Arrow.com.
-
Page 6: Pcb Layout
DEMO MANUAL DC1814A pcB Layout Top Silkscreen Layer 1. Top Layer Layer 2. –VIN 1 Layer 3. –VIN 2 Layer 4. Bottom Layer Bottom Silkscreen dc1814afe Arrow.com. Arrow.com. Arrow.com. Arrow.com. Arrow.com. Arrow.com. Downloaded from Downloaded from Downloaded from Downloaded from Downloaded from Downloaded from... -
Page 7: Parts List
GENERAL BOM FB1-FB4 FERRITE BEAD, 1k, 0805 TDK MPZ2012S102A IC, LTC4274A-1, SINGLE PORT 38.7W PSE CONTROLLER LINEAR LTC4274AIUHF-1 FAB, PRINTED CIRCUIT BOARD DEMO CIRCUIT 1814A DC1814A-B DC1814A GENERAL BOM FB1-FB4 FERRITE BEAD, 1k, 0805 TDK MPZ2012S102A IC, LTC4274A-2, SINGLE PORT 52.7W PSE CONTROLLER... -
Page 8: Schematic Diagram
DEMO MANUAL DC1814A schematic Diagram dc1814afe Arrow.com. Arrow.com. Arrow.com. Arrow.com. Arrow.com. Arrow.com. Arrow.com. Arrow.com. Downloaded from Downloaded from Downloaded from Downloaded from Downloaded from Downloaded from Downloaded from Downloaded from... -
Page 9: 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 representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. - Page 10 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.
Need help?
Do you have a question about the 1814A and is the answer not in the manual?
Questions and answers