• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 62 subscribers
  • Views 305 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

UCC28740: Flyback configuration with HV terminal

Conor
Guru 12400 points
Part Number: UCC28740
Other Parts Discussed in Thread: UCC28C42

Tool/software:

Hi,

I am looking into TI products to replace the FA5536P currently used in the product. The datasheet for FA5536P is here. The points to consider when selecting an IC are as follows:

-Current mode
-HV terminal available
-Fsw can be set to around 130kHz
-Dutymax=80%(typ)

I would like to select an IC with functions as close as possible to the FA5536P. In the TI product lineup, I think UCC28740, UCC28C42, etc. are similar products. Is my understanding correct?

I would also like to know if there are any similar or recommended model numbers compared to the above model numbers.

Thanks,

Conor

  • 0
    TI__Guru 50190 points

    Hi Conor,

    The FA5536P is a fixed frequency controller where the startup circuit has a maximum voltage rating of 500V. This is not normally enough margin to support universal input applications.

    The UCC28740 does have high-voltage startup, but this is a valley switching controller which reduces switching losses by using AM/FM control law which will vary the frequency as a function of load. This actually gives the best overall efficiency from light-load to full load.

    The UCC28C42 is a general purpose PWM controller which would require and external high-voltage startup circuit. If standby power consumption and overall efficiency is not a concern simple resistors can work here. This can be set to run at a fixed frequency of 130kHz,

    Other options to consider are:

    1. UCC28750 - Simple CCM capable controller which does not have high-voltage startup

    2. UCG28826 - This is our newest integrated GaN FET controller. It self-biases itself so eliminates the need for the aux-winding on the transformer. 

    I hope this answers your question.