The UCC28720 flyback power supply controller provides isolated-output Constant-Voltage (CV) and Constant-Current (CC) output regulation without the use of an optical coupler. The devices process information from the primary power switch and an auxiliary flyback winding for precise control of output voltage and current.
An internal 700-V start-up switch, dynamically-controlled operating states and a tailored modulation profile support ultra-low standby power without sacrificing start-up time or output transient response.
Control algorithms in the UCC28720 allow operating efficiencies to meet or exceed applicable standards. The output drive interfaces to a bipolar transistor power switch. Discontinuous conduction mode (DCM) with valley switching reduces switching losses. Modulation of switching frequency and primary current peak amplitude (FM and AM) keeps the conversion efficiency high across the entire load and line ranges.
The controller has a maximum switching frequency of 80 kHz and always maintains control of the peak-primary current in the transformer. Protection features help keep primary and secondary component stresses in check. The UCC28720 allows compensation for voltage drop in the cable to be programmed with an external resistor.
| Top documentation | Type | Title | Format options | Date |
|---|---|---|---|---|
| * | Data sheet | UCC28720 Constant-Voltage, Constant-Current Controller With Primary-Side Regulation datasheet (Rev. B) | PDF | HTML | Sep 30, 2015 |
| Application note | Flyback Aux Winding OVP and UVLO Fault Sensing Design and Troubleshooting Tips | PDF | HTML | Aug 31, 2021 | |
| Application note | Minimize Standby Consumption for UCC287XX Family | Aug 1, 2019 | ||
| Application note | Maximum Output Power and Thermal Considerations for UCC28720 and UCC28722 | Dec 6, 2017 | ||
| Application note | Troubleshooting TI PSR controllers | Oct 3, 2016 | ||
| Technical article | Slim down your flyback; lose that excess snubber | PDF | HTML | Feb 15, 2016 | |
| White paper | Control Challenges for Low Power AC/DC Converters | Oct 2, 2015 | ||
| White paper | Control Challenges for Low Power AC/DC Converters (PPT) | Oct 2, 2015 | ||
| Technical article | Designing multiple output converters with primary side sensing | PDF | HTML | Aug 4, 2015 | |
| Application note | 5-W USB Flyback Design Example Using the UCC28722 | Jan 8, 2014 |
For additional terms or required resources, click any title below to view the detail page where available.
This reference design uses the UCC3895 Phase-Shifted Full Bridge controller to implement a high efficiency, 120VAC input to 44Vdc up to 8A output. The power supply is set up to be constant voltage-constant current. The voltage and current are set by fixed resistor values and could (...)
| Package | Pins | CAD symbols, footprints & 3D models |
|---|---|---|
| SOIC (D) | 7 | Ultra Librarian |
Recommended products may have parameters, evaluation modules or reference designs related to this TI product.
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.