Flyback SMPS design

Swaminath Katte62

Prodigy 120 points

Other Parts Discussed in Thread: UCC28C43, UCC28742

Hi,

I am going to design a flyback smps with below given specifications

Output voltage- 6.5A

Output Current-3A

Efficiency- 85%

I have below queries

1 How to select switching frequency

2. What would be the duty cycle (Min and Max)

3. Max input range that can be acheived

4. Controller selection?

Thanks and Regards,

Swaminath aktte

over 6 years ago

0 Eric Faraci over 6 years ago

TI__Expert 8210 points

Swaminath

We recommend that you use webench http://www.ti.com/design-resources/design-tools-simulation/webench-power-designer.html to help determine which TI device works best for your specification.

Note that TI has two different type of controllers that work for flyback. The first are fixed frequency controllers, where the designer can select the operating frequency. The controller adjusts the duty cycle to regulate the output voltage. Example of this is UCC28C43. The second is a variable frequency controller, where the controller adjusts the frequency and/or duty cycle to regulate the output. Example of this is UCC28742.

The following video goes into more details on the different control types for flyback https://training.ti.com/understanding-basics-flyback-converter

I also recommend that you use our Power Stage Designer tool http://www.ti.com/tool/POWERSTAGE-DESIGNER to determine what the duty cycle and other conditions are for a specific operating point.

Best Regards,

Eric

0 Swaminath Katte62 over 6 years ago in reply to Eric Faraci

Prodigy 120 points

Hi,

Thank you !

I go through these basics and use tool to design my power supply.

Best Regards,

Swaminath

Power management

Power management forum

Flyback SMPS design