85-480VAC Input, Triple Ouput (12V/0.7A) AC/DC Flyback Reference Design


Design files


This reference design generates three separate isolated 12V/0.77A outputs from either an 85-265VAC single phase input or a 200-480VAC-LL three phase input.  The UCC28700 controls a flyback converter power stage.  The primary side regulation feature of the UCC28700 eliminates the need for an optocoupler, reducing cost and complexity.  The three outputs are isolated from each other and can be stacked in series to generate higher output voltages.

  • Accepts 3 phase input voltages up to 480VAC, as well as single phase 85-264VAC
  • Generates three separate isolated 12V/0.7A outputs that can be stacked in series or in parallel for different output voltages/currents
  • Delivers 25W total output power
  • Start-up time <200ms (at 230VAC or higher), <400ms (115VAC
  • Features 960V N-channel power MOSFET switch
  • Primary Side Regulation eliminates optocoupler, reduces cost, increases reliability
Output voltage options PMP10344.2
Vin (Min) (V) 85
Vin (Max) (V) 480
Vout (Nom) (V) 12
Iout (Max) (A) .7
Output Power (W) 8.4
Isolated/Non-Isolated Isolated
Input Type AC
Topology Flyback- DCM^Flyback- Non Sync^Flyback- Quasi Resonant
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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.

TIDUAI6.PDF (5272 K)

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


Detailed schematic diagram for design layout and components


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


Detailed overview of design layout for component placement


PCB layer plot file used for generating PCB design layout


Includes TI products in the design and potential alternatives.

Flyback controllers

UCC28700Constant-voltage, constant-current PWM with PSR & Programmable cable compensation

Data sheet: PDF | HTML

Technical documentation

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Type Title Date
* Test report PMP10344 Test Results Sep. 01, 2015

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