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UCC28700: Attention : Pete Goudreau

robin gangopadhya18
Mastermind 6296 points
Part Number: UCC28700
Other Parts Discussed in Thread: UCC28704, UCC28730, UCC28710

Hi Pete

I do no longer have your email address. So hoping I reach you soon through this community posting

Remember we made the modified version of the UCC28700 controller circuit work in my previous job. ( I am now retired!)?

I have a very innovating product using that chip. I have a question about the application though. 

In the  UCC28700 App Note, one reads about this being used as a charger. But is it really? I am sure the portable devices to which  the output of this circuit connects to must have internal battery charging circuit using the  BQ (or similar) type of current control and end of charging cycle control functions.

Do they not?

So in reality, the circuit  using UCC28700 really is just a CV/CC output that is fed to a charge control circuit inside the portable device such as a smart phone. Would it be possible for you to point me to the right library of circuits   that are suggested  by the TI /BQ family( or similar)  folks for charging/power management inside smart phones or portable?

Hoping to hear from you soon.

I am engaged in developing new products through  a company we formed named "Ganmar Technology"...............we will have a series of interesting products, mostly using TI chips.

-robin gangopadhya

  • 0
    TI__Expert 7395 points
    Robin,
    Thanks for your questions. I can't wait to see your innovation! I hope you will share with the community here when available.
    PSR flybacks like UCC28700 and UCC28704 are typically used in AC/DC mobile chargers and tablet/notebook adapters. They will typically provide a 5V output for USB or similar as seen in this reference design: http://www.ti.com/tool/pmp8757

    . Internal to the phone or the computer though there is also a battery charger IC usually like the bq families that are very popular. You can find those family of devices here: www.ti.com/.../battery-charger-ic-overview.page

    Please let me know if that clarifies.

    Regards,
    John
  • 0 in reply to John Stevens
    Mastermind 6296 points

    John

    thnx for the prompt reply.

    Surely, we will seek your evalauation of these products & hope to be included in your design references. These will be manufactured in the USA very competitively  & we will give you our manufacturing partner's contact as well.

    Now, we have more products in the slow cooking fire.

    So need some quick means to locate application chips:

    -an equivalent controller or similar in  control and pkg: but for dc-dc isolated conversion without opto . With very low start up current. I could use the UCC287xx but nor sure if it will operate as well for ranges 36 to 72v typ being 48V?

    I do use the xl spread sheet for calculations but it  has  protected cells: I need to edit them in order to get realistic values- (do you have the password?)  I could have used the Mathcad version, but unfortunately, I do not have any freeware that will open mathcad files. Do you know of any?

    -robin

  • 0 in reply to robin gangopadhya18
    TI__Expert 7395 points

    Robin,

    Yes UCC28700 can work at that voltage range. as long as you size the aux turns ratio to keep the Vdd within Datasheet range. You can also consider devices with integrated HV startup FETs like UCC28710 or UCC28730. These have faster startup and very low standby power. For these devices as long as you can handle the longer startup time they can also start with >30V.

    passwords for the excels are usually the part number all in lower case. but if you unlock TI can't support you on it because we can't guarantee you didn't change things.

    Regards,

    John

  • 0 in reply to John Stevens
    Mastermind 6296 points
    John
    I finally got time to read about the UCC28730 controller. HV pin function is indeed very impressive. Seems it does somewhat better than UCC2700. Maybe.
    It also seems that you might have a different mathcad model or Excel spread sheet calc for the 28730 , different from the 2700 series. Where can I find these?
    BTW: in the new product I have mentioned to be unique innovation, do you suggest I change to 28730 from 2700? I have advantage of not needing 1 large 2512 SMD resistor from HV to VDD or 2 smaller 1206...we have to do this way in order to guarantee breakdown derating under all conditions across the SMD pads, We use 1206 size whenever there is >100V across the pads. That is a great advantage of this chip: noting that HV pin 7 is 2.54mm away from any other pin
    thnx
  • 0 in reply to robin gangopadhya18
    TI__Expert 7395 points

    Robin,

    UCC28730 is newer than UCC28700 and will be more efficient, faster startup, and lower standby power. I would recommend going forward with the UCC28730. The Excel design calculator (and the interface to do a webench design if you prefer that) is on the tools folder for the UCC28730 here:

    Regards,

    John