• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 151 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

WEBENCH® Tools/LM3481: FET used

Jsoe Rivero
Prodigy 10 points
Part Number: LM3481

Tool/software: WEBENCH® Design Tools

I completed a sepic design a few years ago using Webench from TI. The design calculations resulted in the use of FET from Infineon BSC340N08NS3GATMA1 but now that part has a long lead while the FET BSC22DN20NS3GATMA1 is available now. Can I substitute one part for the other? I have the pdf from Webench but I can not tell by looking at the calculations that the replacement part will work. Can you help? Let me know where I can send the Webench pdf analysis so someone can look at it and let me know if the replacement is OK.

Thank you for prompt the help.

Regards,

Jose

  • 0
    TI__Guru* 78270 points
    Hi Jsoe,

    Thank you for using the LM3481. When replacing the FET, you should make sure the new FET is equivalent to the old one, such that the performance can stay similar. I just checked the datasheets of these two FETs, the old one is 80V rated while the new one is 200V rated, not seemingly to be an appropriate substitute. You should find another 80V rated, having the similar Rds(ON) and total gate charge (Qg). The two FETs' Qg are close but the Rds(ON) has 10x difference, meaning your new FET will have more conduction losses.

    In my opinion, BSZ340N08NS3G seems to be a better replacement that what you intended to use.

    Thanks,
    Youhao