Off-line (non-isolated) AC/DC power supply architectures reference design for grid applications


Design files


This reference design showcases three non-isolated AC/DC power supply topologies for line-powered applications such as residential circuit interrupters, circuit breakers, home automation equipment and appliances for < 100 mA. The three topologies are:

  • Off-line switcher using inductor
  • AC line regulator using switched capacitor (active-clamped capacitor-drop based power supply)
  • Capacitive-drop regulator (cap-drop power supply)

The trade-off between efficiency, start-up time and solution size is done across architectures for various input and output conditions. The design methodology, test data and comparison is included for system designers to quickly evaluate and customize their solution.

  • Off-line switcher using the UCC28880: High efficiency architecture using a buck converter simplifies the design covering universal input voltage – applications requiring fast startup (< 2 ms), small footprint or need to meet stringent surge requirements
  • Switching capacitor-drop power supply using the TPS7A78: Inductor-less architecture customized for a narrow input voltage range  – high efficiency solution for low current (< 30 mA) and a single chip solution with integrated active rectifier and LDO
  • Capacitor-drop (cap-drop) power supply using an LDO: Simplified solution with passive components and LDO – low-cost solution with low efficiency, high startup time and large footprint
??image.gallery.download_en_US?? 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.

TIDUEQ2.PDF (2807 K)

Reference design overview and verified performance test data


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


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


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

TIDRZH9.PDF (1007 K)

PCB layer plot file used for generating PCB design layout


Includes TI products in the design and potential alternatives.

Flyback controllers

UCC28880High voltage switcher for Non-isolated AC/DC Conversion

Data sheet: PDF | HTML
Linear & low-dropout (LDO) regulators

LP2992250-mA, 16-V, low-dropout voltage regulator with enable

Data sheet: PDF | HTML
Linear & low-dropout (LDO) regulators

TPS7A78120-mA, smart, capacitance-drop, low-dropout (LDO) linear voltage regulator

Data sheet: PDF | HTML

Technical documentation

= Top documentation selected by TI
No results found. Please clear your search and try again.
View all 1
Type Title Date
* Design guide Off-Line (Non-Isolated) AC/DC Power Supply Architectures Reference Design for Gr Apr. 12, 2019

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. ​​​​​​​​