120VAC Input, 48V/12V 32W Flyback Reference Design


Design files


This reference design uses the UCC28740 flyback controller to generate both 12-V/1-A and 48-V/0.4-A outputs from a 120-V AC input. The valley switching of the UCC28740 allows this design to provide an efficiency of over 89%; no load losses are less than 80 mW.

  • Peak efficiency approaches 90%
  • Losses at no load are less than 80 mW
  • 120-Vac input generates outputs of 12 V/1 A and 48 V/0.4 A
  • Board length is approximately 64 mm
  • Test report is available
Output voltage options PMP9727.1 PMP9727.2
Vin (Min) (V) 85 85
Vin (Max) (V) 132 132
Vout (Nom) (V) 48 12
Iout (Max) (A) .4 1
Output Power (W) 19.2 12
Isolated/Non-Isolated Isolated Isolated
Input Type AC AC
Topology Flyback- DCM^Flyback- Non Sync^Flyback- Quasi Resonant Flyback- DCM^Flyback- Non Sync^Flyback- Quasi Resonant
Personal electronics
?? View video with transcript Video

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.

TIDUAB9.PDF (2731 K)

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

TIDRG47.PDF (119 K)

Detailed schematic diagram for design layout and components

TIDRG48.PDF (81 K)

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

TIDRG49.PDF (59 K)

Detailed overview of design layout for component placement


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


Includes TI products in the design and potential alternatives.

Flyback controllers

UCC28740Constant-Voltage, Constant-Current (CVCC) Flyback controller with Secondary Side Regulation (SSR)

Data sheet: PDF | HTML
Shunt voltage references

TL431Adjustable precision shunt regulator

Data sheet: PDF | HTML

Technical documentation

= Top documentation selected by TI
No results found. Please clear your search and try again.
View all 2
Type Title Date
* Test report PMP9727 Test Results Jul. 16, 2015
Technical article Power Tips: Voltage mode or current mode? Oct. 02, 2015

Support & training

TI E2E™ forums with technical support from TI engineers

View all forum topics

Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.

If you have questions about quality, packaging or ordering TI products, see TI support. ​​​​​​​​