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UCC28063EVM-723: UCC28063

Robert Forsell
Prodigy 40 points
Part Number: UCC28063EVM-723
Other Parts Discussed in Thread: UC2842, UCC28060, UCC28050

Hi,

This UCC28063EVM-723 requires 13V bias source. How do you propose to get the bias source for this design? should I put an ACDC module in parallel with the AC input? also, the Vcc rating for the part is 14 min 21 max. Why does the evm board only require 13V for biasing? Thank you

Bobb

  • 0
    TI__Guru 74015 points
    Hello Robert,

    In a sysntem where a PFC boost is used generaly there is a stepdown converter to step the PFC outrput voltage to a usable voltage. Genererally there is an aux power sypply in the systeme to power all the logic and power supply controllers. You can always design a flyback using a UC2842 for this application.

    The UVLO turnon for the UCC28060 is 12.6V typical. So you need 13 V to turnon it on. The VCC is rated for 21V so voltage spike that could appear during startup from the aux supply does not damage the device. I also don't believe that you want to run a PWM at 21V due to the IC power disipation, besides you only need 12V to drive a fet.

    Regards,

    Mike
  • 0 in reply to Mike O'
    Prodigy 40 points
    Mike,
    I need to design an AC-DC power supply with wide input AC voltage range. The output DC is 390 Vdc is achievable with this design from the UCC28063EVM-723. The only thing it lacks of is the bias source of 12 Vdc. I plan to use a 12 Vdc/500mA module for the logic and power supply controller. The high dc voltage rail is for the switching power stage. Will the flyback design support 390 Vdc output? Thanks
    Bob
  • 0 in reply to Robert Forsell
    Prodigy 40 points
    Mike,
    After thought, I don't think the flyback design can boost the voltage above 85 volts. I have to use the PFC design. Is there any reference design that has the bias source built-in? if not, what is your recommendation? thanks
    Bob.
  • 0 in reply to Robert Forsell
    TI__Guru 74015 points
    Hello Bob,

    What is your power level?

    Regards,

    Mike
  • 0 in reply to Mike O'
    TI__Guru 74015 points
    Hello Bob,

    I thought about this and you might be able to use the aux windings off the boost inductor to power the IC.

    The following link gets you to a 100W PFC evaluation module using the UCC28050. This is a single stage transition mode PFC boost and uses D6 and D5 to develope the VCC voltage. R5, R6 and R7 are used for trickle charge startup. www.ti.com/.../sluu204.pdf

    When applying this technique you will need to make sure that VCC does not see more than 21V. I believe the truns ratio is 8 on that design so with a 390V output the highest voltage this circuitry would deliver is 48.75V. You would have to step this down with a series pass regulator.

    Regards,

    Mike