Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

  • State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 64 subscribers
  • Views 81 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

UCC2818-EP: UCC2818-EP and UC2854-EP

Rahamadullah A
Prodigy 130 points
Part Number: UCC2818-EP
Other Parts Discussed in Thread: UC2854B-EP, UC2854, UCC2818

Tool/software:

Hi TI team

I would like to know which among these PFC ICs (UCC2818-EP and UC2854-EP) can have <5%THD on the input current for input frequency of 360Hz to 800Hz at input voltage 115Vrms?

Please advise.

  • 0
    TI__Mastermind 32500 points

    Hello Rahamadullah, 

    Actually, both UCC2818-EP and UC2854B-EP PFC controllers are capable of achieving <5% THDi at wide-range avionics input frequencies.
    (The -EP version of UC2854 only comes in the "B" suffix version.)

    UCC2818 and UCC2854 have been successfully used in avionics applications for decades.  It is more challenging to reach <5% distortion at 800Hz input, but it can be done at high load levels. In particular, THD can be held low as long as inductor current operates in CCM, but gets worse rapidly when the current becomes DCM.
    It’s better if the current ripple is relatively low.  That means higher inductance which is a larger, heavier part.

    Low THDi at lighter loads (compared to full power) is more challenging however, and may require extraordinary design measures to maintain.  
    But a swinging-choke design using a metal-alloy powder core can allow higher ripple at max load and less ripple at lighter loads.

    Regards,
    Ulrich