• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 62 subscribers
  • Views 93 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.

UCC2805-Q1: UCC2805-Q1, UCC2803-Q1

seongtaek oh
Prodigy 10 points
Part Number: UCC2805-Q1 
hello? My name is HL mando researcher Seongtaek Oh. 

Currently, we are using UCC2805-Q1 as a Flyback SMPS power device in our internal project. 

Here, the output of the SMPS (= used as gate driver power) requires more load. As a result of taking the duty, I estimate that about 60% to 70% is needed. 

However, the UCC2805 device showed a drop in output voltage when it exceeded 50% Max (=this can be confirmed in the datasheet). 

We would like to replace it with the UCC2803-Q1 device, which increases the Duty Cycle Max to 100%. 

As a result of checking the datasheet, it is determined that only the Duty Cycle Max value increases and the other specifications are completely the same for the two devices. 

Please review whether there will be any issues when replacing only the IC element in the same circuit from UCC2805 to UCC2803.
  • +1
    TI__Guru 51685 points

    Hi,

    UCC2803Q1 duty cycle can be > 50%. A current slope compensation is usually required when a duty cycle > 50% to help resolve subharmonic ripple. You need to add such a current slope compensation in your circuit if your circuit does not have this. The data sheet has a section on slope compensation so you can review that section to make addition to your circuit.

  • 0 in reply to Hong Huang
    Prodigy 10 points 
    Thank you for your kind reply. We plan to reflect the recommendations in the design.