• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 64 subscribers
  • Views 197 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.

UC2825: Can we use 1A Schottkys to clamp gate drive of UC2825?

Andrew Massey
Prodigy 120 points
Part Number: UC2825

Hi,

In UC2825 datasheet, it shows DO201 Schottky diodes (1N5820) being used to clamp the gate drive outputs to ground.

Will it be OK if we use 1A Schottkys for this instead? (ie SD0805S020S1R0)

SD0805S020S1R0

  • 0
    TI__Expert 6515 points

    Hello Andrew,

    The example from the datasheet is a 50W application. If your system power is low enough for the 1A Schottky diode then that should be fine. 

    Best,

    Jonathan Wong

  • 0 in reply to Jonathan Wong
    Prodigy 120 points

    Hi,

    Thankyou, ours is a 500W Full bridge SMPS using UC2825. It has Gate drive transformers, and we    drive them with UC2825. Please advise if a 1A Schottky is ok to clamp the gate drive to ground in this case?

    Also, when the datasheet says 2A gate drive output, what is the voltage in that test, and what may i ask is the external  series impedance?

    We are trying to assess the impedance of the gate drives in the UC2825.?

  • 0 in reply to Andrew Massey
    TI__Expert 6515 points

    Hello Andrew,

    A 500W SMPS is a very high power system. If a 50W design used a 3A Schottky Diode I would not recommend a lower rated 1A Schottky diode for a much higher power system. 

    Are you referring to the max output pulse current as shown below? The Typical Operating Point (TOP) of the output voltage is 5.10 V so it was most likely tested at this voltage. Keep in mind that this is an old product and the datasheet was lasted updated in 2004 so the tests were conducted many years ago.

    Regards,

    Jonathan Wong