120VAC Input 5V/200mA Flyback Converter With BJT Switch Reference Design


Design files


This reference design creates a 5V at 200mA from a 120VAC Input. This supply is to designed to fit into a very small volume with approximately 10mm total height. The UCC28720 primary side controller with a BJT power switch provides a low cost design. A TPS71433 is also used to provide an additional 3.3V rail. It is important to note the outputs are only functionally (not for safety) isolated from the input.

Output voltage options PMP9059.1
Vin (Min) (V) 85
Vin (Max) (V) 132
Vout (Nom) (V) 5
Iout (Max) (A) .2
Output Power (W) 1
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.

SLUUAR3.PDF (1115 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

SLUC496.ZIP (163 K)

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


PCB layer plot file used for generating PCB design layout


Includes TI products in the design and potential alternatives.

Flyback controllers

UCC28720Constant-voltage, constant-current controller with primary-side regulation for bipolar power devices

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

TPS71480-mA 24-V ultra-low-IQ low-dropout (LDO) voltage regulator

Data sheet: PDF | HTML

Technical documentation

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Type Title Date
Test report PMP9059 Test Results Sep. 13, 2013

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