Dual-input redundant PoE PD with smooth transition reference design


Design files


This reference design implements an IEEE802.3bt (draft) Power over Ethernet (PoE) Powered Device (PD) with dual redundant inputs and a smooth transition between these inputs and an auxiliary input.  The design consists of a 5V/6A synchronous flyback converter and allows for up to three power supplies (two PoE Power Source Equipment (PSE) supplies and one AC/DC wall adapter auxiliary supply) to be used in order to decrease the probability of power and data loss in your system.

In need of an IEEE802.3bt-ready PSE controller? Check out the TPS23881.

  • Redundant inputs:  two PoE and 48V adapter
  • Continuous output when switching between inputs
  • 84% efficiency with 5V/6A output and PoE input
Output voltage options PMP20859.1
Vin (Min) (V) 42.5
Vin (Max) (V) 57
Vout (Nom) (V) 5
Iout (Max) (A) 6
Output Power (W) 30
Isolated/Non-Isolated Isolated
Input Type DC
Topology Flyback- Synchronous^POE
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A fully assembled board has been developed for testing and performance validation only, and is not available for sale.

Design files & products

Design files

Download ready-to-use system files to speed your design process.

TIDT030.PDF (1112 K)

Test results for the reference design, including efficiency graphs, test prerequisites and more

TIDRX94.PDF (430 K)

Detailed schematic diagram for design layout and components

TIDRX95.PDF (40 K)

Complete listing of design components, reference designators, and manufacturers/part numbers

TIDRX96.PDF (417 K)

Detailed overview of design layout for component placement

TIDRX98.ZIP (1410 K)

Files used for 3D models or 2D drawings of IC components

TIDCEX3.ZIP (1594 K)

Design file that contains information on physical board layer of design PCB

TIDRX97.PDF (2119 K)

PCB layer plot file used for generating PCB design layout


Includes TI products in the design and potential alternatives.

Boost controllers (external switch)

LM502013-100V Wide Vin, Current Mode PWM Boost, Flyback, Sepic Controller

Data sheet: PDF
N-channel MOSFETs

CSD18504Q5A40-V, N channel NexFET™ power MOSFET, single SON 5 mm x 6 mm, 6.6 mOhm

Data sheet: PDF | HTML
N-channel MOSFETs

CSD19534Q5A100-V, N channel NexFET™ power MOSFET, single SON 5 mm x 6 mm, 15.1 mOhm

Data sheet: PDF | HTML
N-channel MOSFETs

CSD19538Q3A100-V, N channel NexFET™ power MOSFET, single SON 3 mm x 3 mm, 61 mOhm

Data sheet: PDF | HTML
Powered devices

TPS2372IEEE 802.3bt PoE high-power PD interface with automatic MPS & autoclass

Data sheet: PDF | HTML
Shunt voltage references

TLV431A1% accuracy, low-voltage, adjustable precision shunt regulator

Data sheet: PDF | HTML
Supervisor & reset ICs

TPS3808Low-quiescent current supervisor with programmable delay & manual reset

Data sheet: PDF | HTML

Technical documentation

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Type Title Date
* Test report Dual-Input Redundant PoE PD With Smooth Transition Reference Design Oct. 21, 2018

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