70-W flyback and 37-W boost power reference design


Design files


This reference design uses two LM5155 devices to make a flyback and boost power stage. The flyback creates an isolated 28 Vdc bus from a 24 +/-10% Vdc bus and the boost creates a 37 Vdc bus from the output of the flyback. The flyback can be loaded up to 70 W and the boost can be loaded up to 37-W. All components are placed on one side of the board to reduce assembly complexity and cost. Both power stages achieve over 90% efficiency across output conditions.

  • High efficiency flyback and boost power stage
  • Compact size (2" x 3.75") minimizes solution size area
  • Single-side assembly and 2-layer PCB for reduced manufacturing costs
Output voltage options PMP22151.1 PMP22151.2
Vin (Min) (V) 18 27
Vin (Max) (V) 29 29
Vout (Nom) (V) 28 37
Iout (Max) (A) 2.5 1
Output Power (W) 70 37
Isolated/Non-Isolated Isolated Non-Isolated
Input Type DC DC
Topology Flyback- CCM Boost- Non Sync

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.

TIDT150.PDF (2754 K)

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

TIDM336.PDF (165 K)

Detailed schematic diagram for design layout and components

TIDM337.PDF (292 K)

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

TIDM338.PDF (131 K)

Detailed overview of design layout for component placement

TIDM340.ZIP (880 K)

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


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

TIDM339.PDF (587 K)

PCB layer plot file used for generating PCB design layout


Includes TI products in the design and potential alternatives.

Boost controllers (external switch)

LM51552.2-MHz wide VIN, 1.5-A MOSFET driver, non-synchronous boost controller

Data sheet document-pdfAcrobat PDF open-in-new HTML
Shunt voltage references

ATL431LILow-IQ programmable shunt regulator offered in an ultra-small DQN package

Data sheet document-pdfAcrobat PDF open-in-new HTML

Technical documentation

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Type Title Date
* Test report 70-W Flyback and 37-W Boost Power Reference Design Nov. 19, 2019

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