• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Subscribers 63 subscribers
  • Views 566 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.

LM5066: How to check the gate driving capability

user4979999
Prodigy 690 points
Part Number: LM5066

Hi,

How to check the gate driving capability? We need to check the selected MOS Qg?

Didn't see any formula about gate driving in execl tool, the maximum MOS number we can key in is 6.

If customer wants to use 8 or more MOS parallel, how to check if  we can support it? Thanks.

  • 0
    TI__Guru** 105361 points
    Hi Chen,

    The gate driving capability is limited by the charge pump current. It is 20uA (typ) for LM5066 device. The device is able to drive more than 6 MOSFETs. However, more MOSFETs in parallel increases effective capacitance at the GATE and hence the start up time.

    You can unlock the execl tool with device name LM5066 .
    Can you share your system requirements? what is the max. load current and output capacitance.

    Best Regards,
    Rakesh
  • 0 in reply to Rakesh
    TI__Prodigy 690 points
    Hi Rakesh,

    How to know it's ok to drive 6 MOS for LM5066I? Any parameter need to check?
    Can we say it should be ok to drive more MOS, but the start up time will be longer, and need to consider SOA/fault timer is suitable or not? If SOA/fault timer is ok to handle, then there's no other concer?
    Need to consider the MOS turn off time? If we use more MOS, the sink current capability is ok?
    No spec right now, RD wants to check the capability first, for previous design, they have 7kW appliction. (48V/150A/~3000uf)
    Thanks.

    Regards,
    Lynn
  • 0 in reply to user4979999
    TI__Guru** 105361 points
    Hi Lynn,

    Higher startup time decreases SOA margin during startup but this can overcome by using slow dv/dt control. The challenge is to have SOA margin during "hot-short" or "start-into short".
    Design tool helps in quick verification. Use the unlocked excel tool and remove the "data validation" condition for Number of MosFETs. Start with PSMN4R8-100BSE MOSFET.

    Best Regards,
    Rakesh
  • 0 in reply to Rakesh
    TI__Guru** 105361 points
    Hi Lynn,

    Please send me filled-up design calculation tool for review.

    Best Regards,
    Rakesh
  • 0 in reply to Rakesh
    TI__Guru** 105361 points
    Hi Lynn,

    Thanks for sending the files for review. As we are taking forward through email, Please close this thread.

    Best Regards,
    Rakesh