background image

1

DEMO MANUAL DC2911A

Rev. 0

DESCRIPTION

LT4293, LT4321 

IEEE 802.3bt and LTPoE++ 

Interoperable Powered Device 

Demonstration circuit 2911A is an IEEE 802.3bt compli-

ant and LTPoE++ interoperable Power over Ethernet (PoE) 

Powered Device (PD). It features the 

LT

®

4293

 PD interface 

controller and the 

LT4321

 PoE ideal diode bridge controller.

The  LT4293 provides LTPoE++, IEEE 802.3af (PoE, 

Type 1), IEEE 802.3at (PoE+, Type 2), and IEEE 802.3bt 

(PoE++, Type 3 and 4) compliant interfacing. It utilizes an 

external, low R

DS(ON)

 (30mΩ typical) N-channel MOSFET 

for the Hot Swap function to improve efficiency. 
Power good (PWRGD) output indicates the PD control-

ler is ready to provide power to the downstream load. 

This signal can be used to enable an isolated power sup-

ply. The 

T2P

 output indicates the available power from 

the Power Sourcing Equipment (PSE). This signal 

All registered trademarks and trademarks are the property of their respective owners.

PERFORMANCE SUMMARY

BOARD PHOTOS

communicates allocated power from either LTPoE++ 

or IEEE 802.3bt-compliant PSEs to the downstream 

PD circuitry.
The LT4321 controls eight low R

DS(ON)

 (57mΩ typical) 

N-channel MOSFETs to further improve end-to-end power 

delivery efficiency and ease thermal design. This solution 

replaces the eight diodes typically found in a passive PoE 

rectifier bridge.
The DC2911A accepts up to 90W of delivered power from 

a 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.

Design files for this circuit board are available

.

Description
Performance Summary
Board Photos
Typical Performance Characteristics
Quick Start Procedure
Schematic Diagram

PARAMETER

CONDITIONS

VALUE

Port Voltage (V

PORT

)

At RJ45

37V to 57V

Auxiliary Voltage

From AUX+ to AUX– Terminals

37V to 57V

Efficiency

V

PORT

 = 48V, I

OUT

 = 1.5A

99.2% (Typical)

T2P

 Switching Frequency

Connected to an IEEE 802.3bt or LTPoE++ PSE 

That Allocates at Least 38.7W

840Hz (Typical)

Top Side

Bottom Side

Содержание DC2911A

Страница 1: ...ed trademarks and trademarks are the property of their respective owners PERFORMANCE SUMMARY BOARD PHOTOS communicates allocated power from either LTPoE or IEEE 802 3bt compliant PSEs to the downstrea...

Страница 2: ...JP1 and JP2 on the DC2911A board In this configuration any PSE with enough power will turn on this PD Choose a power level from Table 1 and select the corresponding shunt positions 4 Connect the outpu...

Страница 3: ...E Figure 4 Setup Diagram for DC2911A with a DC DC Converter a Microprocessor and an LTPoE PSE QUICK START PROCEDURE DC DC CONVERTER PSE TYPE TO P OPTO ENABLE VIN CAT5e OR CAT6 CABLE RJ45 RJ45 IEEE802...

Страница 4: ...P15 JP16 8 71 3W 90W JP17 JP18 Table 2 T2P Response vs PSE Type PSE TYPE T2P RESPONSE 1 PoE 13W Logic High 2 PoE 25 5W Logic Low 3 PoE 51W 50 Logic Low 4 PoE 71 3W 25 Logic Low LTPoE 90W 75 Logic Low...

Страница 5: ...t limit to 2A Then increase its output voltage to 48V 4 Once the LED D3 on the DC2911A is lit check the output voltage using a voltmeter Output voltage should be within 37V to 57V 5 Verify T2P respons...

Страница 6: ...Z Aux Power N A CLASS 5 40W Hi Z 13W 1 Event Low Z 25 5W 2 Event Low Z 25 5W 3 Event 50 40W 4 Event 50 40W 4 Event 50 40W 4 Event 50 40W 4 Event 75 38 7W 3 Event 75 38 7W 3 Event 75 38 7W 3 Event 75...

Страница 7: ...RES 52 3k 1 1 10W 0603 VISHAY CRCW060352K3FKEA 29 2 R11 R18 RES 0 1 10W 0603 VISHAY CRCW06030000Z0EA 30 1 R12 RES 8 2 1 8W 1 0805 VISHAY CRCW08058R20FKEA 31 1 R13 RES 3 3k 1 10W 5 0603 VISHAY CRCW060...

Страница 8: ...SPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY CONTA...

Страница 9: ...SUPPLIED FOR USE WITH ADI PARTS SCALE NONE www analog com 1 Thursday November 29 2018 2 2 IEEE 802 3bt COMPLIANT LTPoE ERIC H N A LT4293IDD LT4321IUF DEMO CIRCUIT 2911A KIM T INTEROPERABLE POWERED DEV...

Страница 10: ...isclose or transfer any portion of the Evaluation Board to any other party for any reason Upon discontinuation of use of the Evaluation Board or termination of this Agreement Customer agrees to prompt...

Отзывы: