UCC28911: Dual output 12V and 3.3V schematic: UCC28911

prabhu k

Part Number: UCC28911
Other Parts Discussed in Thread: UCC2819,

Tool/software:

Hi,

In our design we are using UCC28911D part, can you please suggest transformer part and schematic for dual output generation: 12V and 3.3V outputs?

1 month ago

0 Mike O' 1 month ago

TI__Guru* 86266 points

Hello,

I am reviewing this and will get back to you shortly.

Regards,

0 prabhu k 1 month ago in reply to Mike O'

Prodigy 175 points

Hello Mike,

Great
Thank you for your support.

0 Mike O' 1 month ago in reply to prabhu k

TI__Guru* 86266 points

Hello,

I don’t know of any off the shelf transformers that you can use for this design.

Typically, you have to design custom magnetics for fly back converters based on your input voltage, output voltage and power level.

I found these application notes on ti.com that can help you design multi output fly back converters using the UCC2819 that you might find helpful.

https://www.ti.com/document-viewer/lit/html/SSZTCD3

https://www.ti.com/lit/an/snva562/snva562.pdf

Regards,

0 prabhu k 1 month ago

Prodigy 175 points

Hi Mike,

Sorry for delay, Can you please suggest flyback transformer for dual output12V & 5V (500mA) and also single output transformer for 12V(500mA)?

0 Ning Tan 1 month ago in reply to prabhu k

TI__Genius 12795 points

Prabhu,

You can refer to our existing ref designs for ideas on the transformer design and example part number, but transformer recommendation is beyond the scope of this forum.

Thanks for the understanding

0 prabhu k 23 days ago in reply to Ning Tan

Prodigy 175 points

Hi Ning,

I am getting 0.4V at transformer output voltage instead of 12V, please check below circuit. could you please review and suggest any corrections required.

0 Mike O' 23 days ago in reply to prabhu k

TI__Guru* 86266 points

Hello,

I reviewed your schematic and I would recommend adding a snubber across D3.

You can use this to reduce ringing to help with EMI and improve overall switch node ring signatures coupled through the transformer.

If you are not starting up, you might be shutting down due to a fault. The following link will link will bring you to an application note that discusses primary fault sensing, similar to what the UCC28911 uses. It describes how it works and the issues with it and how to resolve them. I believe this information will help you troubleshoot your design.

https://www.ti.com/lit/pdf/sluaac5

Regards,

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UCC28911: Dual output 12V and 3.3V schematic: UCC28911