• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 64 subscribers
  • Views 424 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.

bq77PL900 Using N-Channel Mosfets

Todd Petersen
Prodigy 60 points
Other Parts Discussed in Thread: BQ77PL900

Hello,   I've been looking at the bq77PL900 and purchased the evaluation board.   I'm having trouble finding the appropriate P-Channel MOSFETS that meet my 600 amp requirement for my battery pack.   Instead, i've deided on a current dividing circuit that uses N-Channel Mosfets (IRFS3004 from International Rectifier).    I'm having difficulty converting the PMOS driver to an NMOS driver.     Can anyone assist me in creating one that will make the chip function properly?

Todd

  • 0
    Prodigy 231 points

    Hello Todd,

    I was once looking into similar problems. As it is a low priority project, I never (not yet) got around to actually design or build something in this direction. What difficulties in converting the driver are you referring to, exactly?

    Joerg

  • 0 in reply to Jörg Selig
    Intellectual 370 points

    Hello,

    unfortunately, this topic has not yet received a response by TI.
    PMOS economically choice is not the most favorable, this choice always surprise me. 
    Why BQ77910 designed with NMOS and BQ77PL900 with PMOS?
    We use BQ77PL900 in large quantities now with PMOS structure but we have a project where we need imperatively NMOS.
    I would like to say here that this circuit is remarkable, wonderfully thought out in terms of safety and functionalities and price / performance ratio is by far the best on the 5S-10S segment market.
    The difficulty is not so much changes for NMOS but rather to detect the presence of a charger on output.

    if NMOS charge and discharge are open there is no path for ground charger detect... and out of shutdown is impossible. 
    I think using an opto-coupler for do it.

    I guess that TI engineer team has always thought about this case, and i hope they will support us in this reflection.

    Best regards.