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UCC28780: UCC28780 - Is the optical isolation of the clamper drivers and the power transistor driver required?

Part Number: UCC28780
Other Parts Discussed in Thread: UCC27712, ISO7710

Hi All!

I want to build a step-down transformer converter, which will already have a primary-secondary galvanic isolation. 200-400W power.

my questions:

1) I want to make a 200-400watt primary-secondary galvanic isolation flyback converter using UCC28780.

2) I am interested in a simple scheme with a minimum price in the primary part.

3) Open the document

page 53, Figure 54.

I would like to make such a scheme.


In the same document, on page 55, there is a "recommended circuit" Figure 55 + 56 in which you use the "GaN MOSFET PowerIC NV6117and NV6115".

I don’t want to use them, I don’t want to use ISO7710FD opto-isolation, which greatly increases the cost of the project

(see document

, page 6 Figure 4).

I want to use conventional MOSFET transistors from IRF.

Can I do this?

How should I do it ?

Do you have a solution without "GaN MOSFET PowerIC NV6117and NV6115"?


  • Hello Soroka,

    Thanks for your interesting in TI's part.

    UCC28780 is a flyback controller . basically , flyback is used for <150W power level design. so for 200W~400W applications . it maybe will not present a good performance due to the large primary current . and UCC28780 is operation at transition mode.

    If you still want to use UCC28780 in other applications.  of course it can support traditional Silicon Mosfet , what we need is a half-bridge driver . details please find in below reference design schematic.



  • 1) Flyback converters are used, among other things, in the power supply of computers, at capacities of 350-700W.

    these power supplies use dumb-type PWM controllers, without quasi-resonance.

    2) I have my own development on FSFA2100 which works as a flyback converter and produces 450W of power.

    I want to use a controller from Texas Instruments.

    3) I repeat my question: do you need an optical isolation of the drivers?

  • Dear Soroka,

    I repeat my answer : "of course it can support traditional Silicon Mosfet , what we need is a half-bridge driver"  such as UCC27712 indicated in the reference design which I attached in last relpy.

    ISO7710 isolator driver can't directly to driver a silicon MOSFET. for ACF high side GaN FET which integrated driver ,  both of isolator and level shift can driver it. but for high side MOSFET, it need a driver capability , so half-bridge driver is necessary.

    Hope this answered your question.